Patent Publication Number: US-11641842-B2

Title: Methods for enabling pet ownership

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 15/984,857 filed May 21, 2018, which claims priority to Provisional Patent Appl. Ser. No. 62/510,842 filed May 25, 2017, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Cat allergens are produced by cats and can affect pet owners. Allergens can be spread throughout the environment inhabited or frequented by the cat including litter boxes, bedding, counters, floors, etc. 
     Symptoms of cat allergies range from mild rhinitis and conjunctivitis to life-threatening asthmatic responses, and cat allergies are a major roadblock to cat ownership. For example, cat allergy is the primary reason given by cat owners for returning cats to animal shelters. 
     Most cat allergies are caused by a small stable glycoprotein called Fel d1 (Feline domesticus allergen number 1). Cat allergens such as Fel d1 can be released from the litter box into the surrounding area. For example, cats often scratch and shift the cat litter, creating dust by which the cat allergens become airborne in the surrounding area. Similarly, scooping the cat litter can circulate cat allergens into the air. 
     Fel d1 can be particularly problematic because it is lightweight (35 kDa) and thus remains suspended in the air for an extended amount of time. Furthermore, Fel d1 is a sticky protein and consequently adheres to articles within the area surrounding the litter box, such as carpets, walls, furniture, clothing, and curtains, thereby making this allergen difficult to remove after it has circulated from the litter box. 
     SUMMARY 
     The present disclosure relates generally to enabling an individual having a cat allergy to have a cat as a pet. Additionally, such methods can be used for matching prospective pet owners to prospective pets. 
     Accordingly, in a general embodiment, a method of enabling an individual having a cat allergy to have a cat as a pet can comprise quantitatively determining a threshold in the individual for an environmental level of an allergen produced by the cat and selecting a cat or a breed of cat that produces an environmental level of the allergen that is less than the threshold. 
     Additionally, in another embodiment, a method of enabling an individual having a cat allergy to have a cat as a pet can comprise lowering the allergens disseminated by the cat by treating the environment inhabited by the cat during a time period where the cat expresses elevated allergens. 
     Further, in still another embodiment, a method of enabling an individual having a cat allergy to have a cat as a pet can comprise identifying a cat from a plurality of cats based on the identified cat producing less allergen relative to the other cats of the plurality of cats. 
     Yet, in another embodiment, a method of matching a prospective cat owner to a cat can comprise of identifying a cat from a plurality of cats based on the identified cat producing less allergen relative to the other cats of the plurality of cats. 
     Additional features and advantages are described herein and will be apparent from the following Detailed Description and the Figures. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1    shows a perspective view of an embodiment of an apparatus provided by the present disclosure. 
         FIG.  2    shows a schematic diagram of an embodiment of an apparatus provided by the present disclosure. 
         FIG.  3    shows a flowchart of an embodiment of a method provided by the present disclosure. 
         FIG.  4    shows a flowchart of an embodiment of a method provided by the present disclosure. 
         FIG.  5    is a graph of experimental results obtained in Example 1. 
         FIG.  6    is a graph of experimental results obtained in Example 2. 
         FIG.  7    is a graph of experimental results obtained in Example 3. 
     
    
    
     DETAILED DESCRIPTION 
     As used in this disclosure and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. The words “comprise,” “comprises” and “comprising” are to be interpreted inclusively rather than exclusively. Likewise, the terms “include,” “including” and “or” should all be construed to be inclusive, unless such a construction is clearly prohibited from the context. However, the devices disclosed herein may lack any element that is not specifically disclosed. Thus, a disclosure of an embodiment using the term “comprising” includes a disclosure of embodiments “consisting essentially of” and “consisting of” the components identified. 
     The term “pet” means any animal which can produce and/or carry an allergen. The pet can be an avian, bovine, canine, equine, feline, hicrine, lupine, murine, ovine, or porcine animal. The pet can be any suitable animal, and the present disclosure is not limited to a specific pet animal. The term “companion animal” means a dog or a cat. 
     While the terms “individual,” “subject” and “patient” are often used herein to refer to a human, the present disclosure is not so limited. Accordingly, these terms refer to any animal, mammal or human. 
     Ranges are used herein in shorthand to avoid listing every value within the range. Any appropriate value within the range can be selected as the upper value or lower value of the range. Moreover, the numerical ranges herein include all integers, whole or fractions, within the range. 
     All percentages expressed herein are by weight of the total weight of the food composition unless expressed otherwise. When reference is made to the pH, values correspond to pH measured at 25° C. with standard equipment. As used herein, “about” or “substantially” in reference to a number is understood to refer to numbers in a range of numerals, for example the range of −10% to +10%, preferably −5% to +5%, more preferably −1% to +1%, and even more preferably −0.1% to +0.1% of the referenced number. 
     The methods and devices and other advances disclosed herein are not limited to particular methodologies, protocols, and reagents because, as the skilled artisan will appreciate, they may vary. Further, the terminology used herein is for the purpose of describing particular embodiments only and does not limit the scope of that which is disclosed or claimed. 
     Unless defined otherwise, all technical and scientific terms, terms of art, and acronyms used herein have the meanings commonly understood by one of ordinary skill in the art in the field(s) of the present disclosure or in the field(s) where the term is used. Although any compositions, methods, articles of manufacture, or other means or materials similar or equivalent to those described herein can be used, the preferred devices, methods, articles of manufacture, or other means or materials are described herein. 
     In one embodiment, a method of enabling an individual having a cat allergy to have a cat as a pet can comprise quantitatively determining a threshold in the individual for an environmental level of an allergen produced by the cat; and selecting a cat or a breed of cat that creates an environmental level of the allergen that is less than the threshold. 
     Generally, the allergen can be any allergen produced by the cat. In one embodiment, the allergen is Fel d1. Additionally, in one embodiment, quantitatively determining a threshold can include positioning a first allergen source comprising the allergen in a chamber, distributing the allergen from the allergen source in the chamber, having the individual in the chamber, and measuring the symptoms of the individual, as described herein. In one aspect, the allergen source can comprise a predetermined concentration of the allergen and the individual is symptomatic at the predetermined concentration, thereby providing the threshold of the individual. Additionally, in another aspect, the distributing of the allergen can be performed for a predetermined time period. In one embodiment, quantitatively determining a threshold can include exposing the individual to a predetermined concentration of allergen from an allergen source such that the individual is symptomatic, thereby providing the threshold of the individual. 
     The allergen source can be any material having the cat allergen. In one embodiment, the allergen source can be cat hair and the exposing of the allergen can be performed for a predetermined time period. 
     Generally, the present methods can be used with any cat or to match any cat with any prospective owner. As such, in generally, cats can be quantified as high, medium, and low allergen producers where high allergen producers produce an average salivary Fel d1 concentration from 10 to 100, or higher, μg/ml, where medium allergen producers produce a salivary Fel d1 concentration between 5 and 10 μg/ml, and where low allergen producers produce a salivary Fel d1 concentration between 0.01 and 5 μg/ml. In some aspects, the cat can produce a salivary Fel d1 concentration of less than 4, 3, 2, or even 1 μg/ml. In other aspects, the cat can produce a salivary Fel d1 concentration of more than 10, 15, 20, 25, 30, or even 50 μg/ml. While the threshold can be individually determined for any subject, in one embodiment, the threshold can be higher than the Fel d1 concentration present in an environment, such as a home, where the cat is a high allergen producer. In one aspect, the cat can be a medium allergen producer. In another aspect, the cat can be a low allergen producer. 
     In another embodiment, a method of enabling an individual having a cat allergy to have a cat as a pet can comprise lowering the allergens disseminated by the cat by treating the environment inhabited by the cat during a time period where the cat expresses elevated allergens. 
     Lowering the allergens or treating the environment can be by any method that removes or degrades the allergen, or otherwise inhibits the binding of the allergen in a human. In one embodiment, treating the environment can include shampooing the cat to remove allergen from the cat. In another embodiment, treating the environment can include wiping, contacting, or cleaning a member selected from the group consisting of counters, floors, furniture, bedding, and walls, with an antibody that binds to the allergen. In still another embodiment, treating the environment includes oral administering to the cat antibodies that bind to the allergens. In one aspect, the antibodies can be polyclonal antibodies. In another aspect, the antibodies can be part of a food composition. Generally, the elevated allergens can be measured as a correlation to an average salivary Fel d1 concentration produced by the cat. In one aspect, the allergens can be lowered by at least 50%. In other aspects, the allergens can be lowered by 60%, 70%, 80%, 90%, 95%, or even 99%. 
     While the present methods can be used at any time during the year, the present inventors have discovered that some cats can produce a season high allergen load at specific periods of year. As such, in one embodiment, the time period can be from November to February. In another aspect, the time period can be from July to September. Regardless of time period, the present methods include enabling cat ownership by treating a cat having elevated levels of Fel d1 whether it be at a specific time of the year or a period specific to an individual cat. 
     In addition to the above, a method of enabling an individual having a cat allergy to have a cat as a pet or a method of matching a prospective cat owner to a cat can comprise identifying a cat from a plurality of cats based on the identified cat producing less allergen relative to the other cats of the plurality of cats. In one aspect, the cat can be a high Fel d1 producer. In another aspect, the cat can be a medium Fel d1 producer. In still another aspect, the cat can be a low Fel d1 producer. 
     Various apparatuses can be used to determine the threshold of an owner or prospective owner as well as environment level produced by the cat. The following description provides an example of such apparatuses. 
       FIGS.  1  and  2    generally illustrate an embodiment of an apparatus  10  provided by the present disclosure. The apparatus  10  can generate and can measure environmental levels of an allergen as discussed in detail hereafter. The apparatus  10  can comprise a housing  20 , an allergen source  30 , and an air circulation device  41 . The housing  20  is preferably portable; in an embodiment, the housing  20  is a collapsible tent. As used herein, a “collapsible” article is capable of being configured into a smaller size without causing damage to the article, preferably without the need for tools. 
     The housing  20  can form a chamber. Although the housing  20  can be air-tight, the housing  20  does not have to be air-tight, and an embodiment of the housing  20  merely forms a closed system such that the tested allergen does not exit the interior of the housing  20  during use of the apparatus  10  and additional allergen does not enter the interior of the housing  20  during use of the apparatus  10 . 
     As shown in  FIG.  1   , the housing  20  can comprise a frame  22  that supports a shell  24  to form the chamber. In an embodiment, the frame  22  is made of a metal material. Preferably the shell  24  is made of non-porous material. The shell  24  can define the interior of the housing  20 . For example, the shell  24  can form a majority of the outer surface of the housing  20  (e.g. substantially all of the outer surface of the housing  20 ) and/or a majority of the inner surface of the housing  20  (e.g. substantially all of the inner surface of the housing  20 ). 
     Preferably at least a portion of the housing  20  can be folded to enable transportation and compact storage. For example, at least a portion of the frame  22  and/or at least a portion of the shell  24  can be folded to enable transportation and compact storage of the housing  20 . The housing  20  can be arranged in (i) an operative configuration in which the housing  20  defines an interior and (ii) a storage/transport configuration in which the housing  20  defines an interior that is smaller relative to the operative configuration or in which the housing  20  does not define an interior e.g. the housing  20  is folded completely upon itself. For example, the frame  22  can comprise one or more poles that can be configured in (i) an operative configuration in which the poles are inserted into each other at their ends to form a substantially rigid and/or stable arrangement and (ii) a storage/transport configuration in which the poles are in a compact arrangement, such as laying side-by-side with each other. The poles can be hollow and connected to each other by one or more cords, such as rubber ropes, that pass through the interiors of the poles to enable a user to move the housing  20  between configurations and arrange the housing  20  in the desired configuration. 
     The shell  24  is preferably flexible; for example, the shell  24  can comprise a fabric such as polyester, a plastic such as flexible polyvinyl, and/or linoleum. The shell  24  can be made of a material that can be easily cleaned, for example with isopropyl or ethanol solutions, such that no measurable allergen remains in the housing  20  after cleaning. In an embodiment, the housing  20  is at least partially disposable; for example, the frame  22  and/or the shell  24  can be disposable. As used herein, a “disposable” article is designed for a single use after which it is recycled or is disposed as solid waste. For example, a disposable article is not permanently fixed in position in a building, and a disposable article can be moved from its position without damaging the article. 
     The shell  24  can be connected to the frame  22  to form the housing  20 . For example, a portion of the shell  24  can be reversibly attachable to and removable from the frame  22 . Alternatively or additionally, a portion of the shell  24  can be fixedly attached to and/or integral with the frame  22 . The shell  24  can comprise a door  26  that opens and closes, for example by a zipper. The bottom of the shell  24  can be secured to a solid surface, for example by floor tape  27 . In an embodiment, the shell  24  does not have an integrated floor; additionally or alternatively, a portion of the shell  24  can comprise an integrated floor. If the bottom of the shell  24  is secured to a solid surface, preferably the solid surface does not have carpet. 
     Referring again to  FIGS.  1  and  2   , the housing  20  in the operative configuration can have any size, preferably at least large enough to contain a human seated on a chair or stool  28 . The housing  20  in the operative configuration can have a width  21 . As non-limiting examples, the width  21  can be at least three feet, preferably at least four feet, more preferably at least five feet, most preferably at least six feet, and/or the width  21  can be at most nine feet, preferably at most eight feet, more preferably at most seven feet. In an embodiment, the width  21  is about six feet, but the housing  20  in the operative configuration is not limited to a specific distance of the width  21 . 
     The housing  20  in the operative configuration can have a depth  23  perpendicular to the width  21 . As non-limiting examples, the depth  23  can be at least three feet, preferably at least four feet, more preferably at least five feet, most preferably at least six feet, and/or the depth  23  can be at most nine feet, preferably at most eight feet, more preferably at most seven feet. In an embodiment, the depth  23  is about six feet, but the housing  20  in the operative configuration is not limited to a specific distance of the depth  23 . 
     As shown in  FIG.  1   , the housing  20  in the operative configuration can have a height  25 . As non-limiting examples, the height  25  can be at least four feet, preferably at least five feet, more preferably at least six feet, and/or the height  25  can be at most ten feet, preferably at most nine feet, more preferably at most eight feet. In an embodiment, the height  25  is about seven feet, but the housing  20  in the operative configuration is not limited to a specific distance of the height  25 . Preferably the width  21  is substantially the same for the majority of the height  25  of the housing  20  and/or the depth  23  is substantially the same for the majority of the height  25  of the housing  20 , although the housing  20  can taper at the top end thereof in a non-limiting embodiment shown in  FIG.  1   . 
     As noted above, the housing  20  in the transport/storage configuration defines an interior that is smaller relative to the operative configuration or does not define an interior e.g. the housing  20  is folded completely upon itself. For example, at least one of the width  21 , the depth  23  or the height  25  is less in the transport/storage configuration than the operative configuration, and preferably all three are less in the transport/storage configuration than the operative configuration. In an embodiment, the housing  20  in the transport/storage configuration can be positioned within and carried by a conventional backpack. 
     Referring to  FIG.  2   , the allergen source  30  can be positioned within the housing  20 . The allergen source  30  can be any source of an allergen, preferably an allergen from a pet, more preferably from a companion animal, most preferably from a cat. For example, the allergen source  30  can be a cat litter box that contains cat litter soiled by urine and/or feces. As another example, the allergen source  30  can be an open container in which cat hair is positioned. An “allergen” is any substance that can produce an immune response in some individuals but is otherwise harmless to such individuals. 
     The air circulation device  41  can be positioned within the housing  20 . The air circulation device  41  can be any device that suspends and/or distributes at least a portion of the allergen from the allergen source  30 . For example, the air circulation device  41  can be at least one mechanical fan comprising a rotating arrangement of vanes or blades that extend from a hub. In a preferred embodiment, the air circulation device  41  can comprise a primary fan, and the apparatus  10  can comprise an additional air circulation device  42  that can comprise a secondary fan such as an oscillating fan. An “oscillating fan” is a fan for which the hub rotates on at least two axes, namely the axis of rotation of the vanes/blades and another axis that is different than the axis of rotation of the vanes/blades. Preferably the other axis of the oscillating fan is perpendicular to the axis of rotation of the vanes/blades. 
     The air circulation device  41  and the additional air circulation device  42  can direct air to circulate the allergen from the allergen source  30  into the environment of the interior of the housing  20 . For example, the air circulation device  41  can be positioned to blow or otherwise direct air at and/or across the allergen source  30 , and the additional air circulation device  42  can be positioned on the directly opposite side of the allergen source  30  from the air circulation device  41  to blow or otherwise direct air in the opposite direction and thus produce air turbulence adjacent to and/or above the allergen source  30 . This air turbulence can maintain particles from the allergen source  30  in suspension in the environment of the interior of the housing  20  during testing. For example, in an embodiment where the allergen source  30  comprises a cat litter box, the air turbulence from the air circulation device  41  and the additional air circulation device  42  can distribute and/or suspend cat litter particles in the interior of the housing  20 . 
     The apparatus  10  can comprise a collection device  50  that can be positioned within the housing  20 . The collection device  50  can be any device capable of collecting the allergen and/or particles comprising the allergen. In an embodiment, the collection device  50  comprises one or more petri plates  52 . As a non-limiting example, the one or more petri plates  52  can comprise 10 cm petri plates pre-coated with a 2% gelatin solution from cold water fish skin. The one or more petri plates  52  can be positioned adjacent to each other or in different locations in the housing  20 . As a non-limiting example, some of the petri plates  52  can be positioned on the floor approximately 10 cm from the edge of the allergen source  30 , and some of the petri plates  52  can be positioned on a table  54 , such as a 1 m table approximately 1 m from the allergen source  30 . 
     The air circulation device  41  and the additional air circulation device  42  can be activated for a predetermined time period, and the material collected by the collection apparatus  50  can be extracted after the predetermined time period. The collected material can be extracted using any compound capable of removing the allergen from the collection device  50 , for example a solution of phosphate buffered saline, 0.1% polysorbate  20  such as TWEEN® 20, and 0.15% antimicrobial such as KATHON® (“PBS-Tk”). 
     Then the material extracted from the collection device  50  can be assayed to determine the quantity of allergen emitted from the allergen source  30  during the predetermined time period. In an embodiment, the extracted material can be assayed to determine the quantity of Fel d1 emitted from a soiled cat litter box during a predetermined time period. For example, the extracted material can be assayed for Fel d1 using a commercially available Fel d1 enzyme-linked immunosorbent assay (ELISA) kit such as Product Code EL-FD1 from Indoor Biotechnologies. The allergen can be quantitated as ng/plate/hour. 
     As discussed in further detail in Example 1 later in this application, the present inventors verified the effectiveness of the apparatus  10 . For example, two soiled litter boxes from the same cat were used for different amounts of time (in days). The longer the cat had used the litter box (allergen source  30 ), the higher the level of Fel d1 that was emitted into the housing  20  by the litter box (allergen source  30 ), collected by the collection device  50 , and quantitated by assay. 
     In a preferred embodiment, the apparatus  10  is configurable. For example, one or more of the allergen source  30 , the air circulation device  41 , the additional air circulation device  42 , or the collection device  50  can be movable relative to the housing  20  e.g. not fixedly attached to the housing  20 . As another example, the shell  24  can comprise portals for sampling or injecting allergen e.g. at least a portion of the allergen source  30  can be positioned exterior relative to the housing  20 , and/or at least a portion of the collection device  50  can be positioned exterior relative to the housing  20 . As yet another example, a pipe can be attached to and/or insert through the shell  24 . The pipe can be used to establish and/or maintain a desired pressure in the interior of the housing  20 , for example a positive pressure, a negative pressure, or an ambient pressure. If a pipe is used, preferably the apparatus  10  still provides the closed system in which the tested allergen does not exit the interior of the housing  20  during use of the apparatus  10  and additional allergen does not enter the interior of the housing  20  during use of the apparatus  10 . 
     Another aspect of the present disclosure is a method  100  of generating and measuring environmental levels of an allergen, for example an allergen from a companion animal such as a cat. An embodiment of the method  100  is generally illustrated in  FIG.  3   . The method  100  can employ the apparatus  10  and/or another apparatus. 
     In Step  102 , air can be directed at and/or across a first allergen source that is preferably contained within a chamber that provides a closed system. The chamber can contain one or more collection devices. Additionally or alternatively, one or more collection devices can be outside of the chamber but have access to the interior of the chamber through one or more portals. Step  102  is preferably performed for a predetermined time period. 
     One or more air circulation devices, preferably positioned within the chamber, can direct the air at and/or across the first allergen source during Step  102 . The one or more air circulation devices can be any device capable or suspending and/or distributing the allergen in the chamber. In an embodiment, a primary fan can be positioned to blow or otherwise direct air at and/or across the first allergen source. A secondary oscillating fan can be positioned on the directly opposite side of the first allergen source from the primary fan to blow or otherwise direct air in the opposite direction and thus produce air turbulence adjacent to and/or above the first allergen source. This air turbulence can maintain particles from the first allergen source in suspension in the environment of the interior of the housing during testing. 
     In Step  104 , material collected by the one or more collection devices can be extracted, for example after Step  102  is completed. Each of the one or more collection devices can be any device capable of collecting the allergen and/or particles comprising the allergen. For example, the one or more collection devices can comprise petri plates at various positions within the chamber. The material can be extracted using any compound capable of removing the allergen from the one or more collection devices, for example a phosphate-buffered solution. 
     In Step  106 , the extracted material can be assayed to determine the quantity of the allergen collected by the one or more collection devices. Any assay capable of identifying a quantity of the allergen can be used, for example an ELISA kit. The quantity of the allergen collected by the one or more collection devices during the test can be indicative of the quantity of allergen emitted by the allergen source during the test. 
     In an embodiment, the method  100  can measure the effectiveness of various approaches implemented to reduce environmental levels of an airborne allergen. In such an embodiment, the method  100  can be repeated with a second allergen source that is different than the first allergen source. In such an embodiment, Steps  102 ,  104  and  106  are preferably performed the same as they were previously performed, other than the different allergen sources. 
     The second allergen source can be a cat litter box that has been subjected to at least one different condition than the first cat litter box and/or has at least one different characteristic relative to the first cat litter box. For example, the first allergen source can be a first cat litter box used by a first specific cat, and the second allergen source can be a second cat litter box used by a second specific cat. Other than the different specific cats, the first and second cat litter boxes can be subjected to one or more same or similar conditions, for example the same type of cat litter, one or more of the same location, the same time period of use, or the same amount of waste matter deposited therein. In this example, the method  100  can determine which of the specific cats sheds less allergen. By using the method  100  to measure which specific cat sheds less allergen, an individual can select a cat that minimizes or prevents the individual&#39;s exposure to the allergen. 
     As another example, the first allergen source can be a first cat litter box used by a first breed of cat, and the second allergen source can be a second cat litter box used by a second breed of cat. Other than the different breeds of cat, the first and second cat litter boxes can be subjected to one or more same or similar conditions, for example the same type of cat litter, one or more of the same location, the same time period of use, or the same amount of waste matter deposited therein. In this example, the method  100  can determine which breed of cat sheds less allergen. By using the method  100  to measure which breed of cat sheds less allergen, an individual can select a breed of cat that minimizes or prevents the individual&#39;s exposure to the allergen. 
     As yet another example, the first allergen source can be a first cat litter box containing a first type of cat litter, and the second allergen source can be a second cat litter box containing a second type of cat litter. Other than the different types of cat litter, the first and second cat litter boxes can be subjected to one or more same or similar conditions, for example one or more of the same location, the same time period of use, the same amount of waste matter deposited therein, use by the same breed of cat, or use by the same specific cat. In this example, the method  100  can determine which of the first and second types of cat litter is more effective at preventing emission of the allergen from the litter box. By using the method  100  to measure which type of cat litter is more effective at preventing emission of the allergen from the litter box, an individual can select a type of cat litter that minimizes or prevents the individual&#39;s exposure to the allergen. 
     As still another example, the first allergen source can be a first cat litter box used by a cat that has been provided a first diet, and the second allergen source can be a second cat litter box used by a cat that has been provided a second diet. The cat that has been provided the first diet can be the same breed or the same specific cat as the cat that has been provided the second diet. Other than the different diets of the cat(s), the first and second cat litter boxes can be subjected to one or more same or similar conditions, for example one or more of the same location, the same time period of use, the same amount of waste matter deposited therein, the same type of cat litter, use by the same breed of cat, or use by the same specific cat. In this example, the method  100  can determine which of the first and second diets results in the cat producing less of the allergen relative to the other diet. By using the method  100  to measure which diet is more effective at preventing allergen production, an individual can administer a diet to the cat that minimizes or prevents the individual&#39;s exposure to the allergen. 
     As an even further example, the first allergen source can be an allergen source that collected allergen in a first location, such as a first room of a house, and the second allergen source can be an allergen source that collected allergen in a second location different than the first location, such as a second room of the house. Other than the location at which the allergen sources are positioned, the first and second allergen sources can be subjected to one or more same or similar conditions, for example the same time period of use and/or use by the same specific cat. In this example, the method  100  can determine which of the locations contains less of the allergen relative to the other location. By using the method  100  to determine which location contains more allergen, an individual can avoid the location to thereby minimize or prevent exposure to the allergen. 
     The second allergen source can be used in the same chamber as the first allergen source after the testing of the first allergen source is completed and preferably after the chamber is cleaned. Alternatively, the second allergen source can be used in a different chamber than the first allergen source, for example substantially contemporaneously; the chambers are preferably substantially the same, for example the same dimensions and/or the same materials. 
     In another embodiment, a method  200  can expose a subject, preferably one or more human subjects, to an allergen to evaluate the symptoms of the subject. The method  200  can employ the apparatus  10  and/or another apparatus. 
     In Step  202 , which is optional, the subject is absent while a chamber that provides a closed system is loaded with an allergen. In an embodiment, the subject can be absent during a predetermined time in which air is directed at and/or across a first allergen source contained within the chamber. For example, the allergen can be distributed in the apparatus for a predetermined time period without the subject, such as thirty-six hours. 
     The chamber can contain one or more collection devices. Additionally or alternatively, one or more collection devices can be outside of the chamber but have access to the interior of the chamber through one or more portals. 
     In Step  204 , the subject is present in the chamber that provides a closed system while the allergen is distributed and/or circulated therein. In an embodiment, the subject can be present in the chamber during a predetermined time in which air is directed at and/or across a first allergen source contained within the chamber. For example, the subject can be within the chamber with the allergen circulating for a predetermined time period, such as four to eight hours. 
     One or more air circulation devices, preferably positioned within the chamber, can direct the air at and/or across the first allergen source during Steps  202  and  204 . The one or more air circulation devices can be any device capable or suspending and/or distributing the allergen in the chamber. In an embodiment, a primary fan can be positioned to blow or otherwise direct air at and/or across the first allergen source. A secondary oscillating fan can be positioned on the directly opposite side of the first allergen source from the primary fan to blow or otherwise direct air in the opposite direction and thus produce air turbulence adjacent to and/or above the first allergen source. This air turbulence can maintain particles from the first allergen source in suspension in the environment of the interior of the housing during testing. 
     In Step  206 , material collected by the one or more collection devices can be extracted, for example after Step  204  is completed. Each of the one or more collection devices can be any device capable of collecting the allergen and/or particles comprising the allergen. For example, the one or more collection devices can comprise petri plates at various positions within the chamber. The material can be extracted using any compound capable of removing the allergen from the one or more collection devices, for example a phosphate-buffered solution. 
     In Step  208 , the extracted material can be assayed to determine the quantity of the allergen collected by the one or more collection devices during the test. Any assay capable of identifying a quantity of the allergen can be used, for example an ELISA kit. The quantity of the allergen collected by the one or more collection devices during the test can be indicative of the quantity of allergen emitted by the allergen source during the test. 
     In Step  210 , the symptoms, if any, of the subject in response to the airborne allergen can then be evaluated to determine the sensitivity of the subject to the allergen. The symptoms, if any, of the subject can be correlated to the quantity of the allergen emitted from the allergen source during these test. 
     The method  200  can measure the symptoms of the subject at various environmental levels of the allergen. In such an embodiment, Steps  202 ,  204 ,  206  and  208  can be repeated, for example with the predetermined time period of Step  204  being different, or with a second allergen source different from the first allergen source (subjected to at least one different condition and/or has at least one different characteristic, e.g. the amount of the allergen in the allergen source is different). The method  200  can be used determine a threshold amount of allergen at which symptoms are induced in the subject. The threshold amount of allergen for the subject can be used to select an appropriate pet for the subject to own, for example a specific breed of cat or a specific cat, such that the pet does not induce allergic symptoms in the subject or induces tolerable allergic symptoms in the subject. 
     In an embodiment of the method  200 , a predetermined amount of the allergen can be provided in the allergen source. For example, hair from a cat may be assayed to determine the concentration of the allergen in the hair, and then the hair may be provided in the allergen source in an amount that contains the desired amount of allergen. The predetermined amount of the allergen can be used to determine the symptoms of the subject in response to the predetermined amount, and various predetermined amounts can be used to determine a threshold amount of allergen that must be exceeded to induce the symptoms in the specific subject. 
     EXAMPLES 
     By way of example and not limitation, the following non-limiting examples are illustrative of apparatuses and methods of generating and measuring environmental levels of an allergen in embodiments provided by the present disclosure. 
     Example 1 
     A first experiment was performed regarding differential loading of environmental chambers using different mass amounts of cat hair from the same cat. Three environmental chambers were loaded with 1, 0.5 or 0.25 g of cat hair from the cat “Montana.” Dust was collected using petri plates coated with 0.2% gelatin for 72 hours. 
     The dust was extracted from the petri plates and analyzed for Fel d1 using a commercially available ELISA kit (Indoor Pharmaceuticals). The level of Fel d1 was then normalized to time (ng Fel d1/plate/hour). Each dust collection was done in triplicate. Results are shown in the table below and  FIG.  5    and show that the amount of allergen source corresponds closely to the level detected in the environmental chamber. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Fel d1 Levels in ECs 
                   
               
               
                   
                 grams or hair 
                 ng Fel d1/plate/hr 
                 SD 
               
               
                   
                   
               
             
            
               
                   
                  1.0 g 
                 0.087 
                 0.015 
               
               
                   
                  0.5 g 
                 0.060 
                 0.006 
               
               
                   
                 0.25 g 
                 0.015 
                 0.006 
               
               
                   
                   
               
            
           
         
       
     
     Example 2 
     A second experiment was performed in which three environmental chambers were loaded with 1 g of hair from three different cats, namely high, medium and low level Fel d1-producing cats. The level of Fel d1 for each cat was determined by measuring the Fel d1 in their hair and normalizing to mass amount of hair (ng Fel d1/mg hair). The hair from each cat was measured in triplicate. 
     Fel d1 levels in the cat hair used to load the environmental chambers are shown in the table below. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Cat 
                 ng Fel d1/mg hair 
               
               
                   
                   
               
             
            
               
                   
                 Montana 
                 828 ng/mg hair 
               
               
                   
                 Stymie 
                 277 ng/mg hair 
               
               
                   
                 Koala 
                  16 ng/mg hair 
               
               
                   
                   
               
            
           
         
       
     
     The dust was extracted from the petri plates and analyzed for Fel d1 as previously described in Example 1. Results are shown in the table below and  FIG.  6    and show that the allergen production of the cat corresponds closely to the level detected in the environmental chamber. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                   
                 House Fel D1 levels 
                   
               
               
                   
                 Location 
                 ng Fel d1/plate/hr 
                 SD 
               
               
                   
                   
               
             
            
               
                   
                 JL 
                 0.055 
                 0.0076 
               
               
                   
                 CT CR (cat) 
                 0.049 
                 0.0028 
               
               
                   
                 CT BR (no cat) 
                 0.009 
                 0.0086 
               
               
                   
                   
               
            
           
         
       
     
     Example 3 
     A third experiment was performed in which the level of Fel d1 in homes of cat owners was determined by collecting dust using the method described previously in Example 1. Dust was collected in “cat rooms” and “cat-free rooms” when possible in the same household. Dust was collected for 5 days (120 hours). Results are shown in the table below and  FIG.  7    and show that the allergen production of the cat corresponds closely to the level detected in the environmental chamber. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                   
                 House Fel D1 levels 
                   
               
               
                   
                 Location 
                 ng Fel d1/plate/hr 
                 SD 
               
               
                   
                   
               
             
            
               
                   
                 JL 
                 0.055 
                 0.0076 
               
               
                   
                 CT CR (cat) 
                 0.049 
                 0.0028 
               
               
                   
                 CT BR (no cat) 
                 0.009 
                 0.0086 
               
               
                   
                   
               
            
           
         
       
     
     Example 4 
     Adult domestic shorthair cats were enrolled at two different locations: St. Joseph, Mo.—Study 1 (N=27) and Fergus, Ontario—Study 2 (N=37). Data collection started in the spring for Study 1 and in the fall for Study 2. In Study 1, 74% (N=20) of cats were male and 26% (N=7) were female. In Study 2, 19% (N=7) of cats were male and 81% (N=30) were female. All cats were either spayed or neutered. At the start of the study, the cats were on average 7.89 years old (SD=4.92) for Study 1 and 8.70 years old (SD=2.63) for Study 2. The cats weighed an average of 5.43 kg (SD=0.22) for Study 1 and 3.57 kg (SD=0.27) for Study 2. In addition to weight, the body condition score for each cat was measured. A body condition score was assigned to each cat based on a 9-point scale (1-3 too thin, 4-5 ideal, and 6-9 too heavy) (Laflamme, 1997). The average BCS was 6.34 (SD=0.53) for Study 1 and 6.51 (SD=0.67) for Study 2. 
     In both studies, salivary Fel d1 was measured twice a day, every other day for a year duration. Not all the saliva collections were performed as planned, the cause of the interruptions included: unrelated health issues, moving cats into a new building, and the removal of cats due to their enrollment in concurrent studies. 
     The average number of days where salivary Fel d1 was measured was 144.43 (SD=11.25) for study 1 and 128.11 (SD=43.83) for study 2. Cats were measured at two points during the day, during the morning and during the afternoon. 
     Saliva collection was performed with commercially available Salivette® (Sarstedt, Nümbrecht, Germany) following the manufacturer&#39;s instructions (Park et al., 2008; Poll et al., 2007). Cat saliva samples were obtained by letting cats chew on Salivette that absorbs saliva. The saliva was then extracted by centrifuging the Salivettes, then they were stored at −80° C. until they were analyzed with a commercial Fel d1 ELISA kit (Indoor Technologies). The samples inventory of study 2 included if the amount of saliva collected was below 100 μl. 
     About 0.2 grams of hair was collected by grooming each cat with a new grooming brush. The hair was then stored in individual plastic bags at 2-8° C. until extraction. Extractions were performed in triplicates by weighing 15 to 30 mg of hair, then adding 200 μl of PBS 0.1% for each mg of hair. After overnight shaking, the supernatant was transferred to a new tube, centrifuged at 1000 g for 10 min, then transferred and centrifuged once again. The resulting supernatant was stored at −20° C. until it was analyzed with the same commercial Fel d1 ELISA kit used in measuring salivary Fel d1. The final result on the Fel d1 analysis was the average of the 3 extracts per hair collection. 
     To examine the relationship between alternative methods of measuring Fel d1, a comparison was done between salivary and hair Fel d1 measures using a subset of cats from study 1. These two were strongly related to each other (r=0.85, p&lt;0.01), even though there was a year gap between when the salivary Fel d1 and hair Fel d1 were collected. 
     Saliva data (μg Fel d1/ml of saliva) collected twice daily every other day over a year from study 1 and study 2 is presented in table 5. Saliva data (μg Fel d1/ml of saliva) collected once daily every other day over a year from Study 1 and Study 2 is presented in table 6. 
     
       
         
           
               
               
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                   
                 Study 1 
                 Study 2 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Average 
                   
                   
                 Average 
                   
                   
               
               
                   
                 (μg Fel d1/ml 
                 Number of 
                 Number of 
                 (μg Fel d1/ml 
                 Number of 
                 Number of 
               
               
                   
                 of saliva) 
                 measures 
                 cats 
                 of saliva) 
                 measures 
                 cats 
               
               
                   
               
               
                 January 
                 5.84 
                 590 
                 24 
                 11.35 
                  907 
                 37 
               
               
                 February 
                 5.08 
                 528 
                 16 
                 10.54 
                  926 
                 37 
               
               
                 March 
                 4.50 
                 416 
                 16 
                  7.48 
                  902 
                 37 
               
               
                 April 
                 4.70 
                 542 
                 23 
                  7.37 
                  923 
                 37 
               
               
                 May 
                 6.38 
                 958 
                 26 
                  6.60 
                  956 
                 37 
               
               
                 June 
                 6.73 
                 604 
                 24 
                  6.36 
                  950 
                 37 
               
               
                 July 
                 7.12 
                 612 
                 24 
                  7.56 
                  897 
                 37 
               
               
                 August 
                 7.18 
                 635 
                 24 
                  5.83 
                 1013 
                 37 
               
               
                 September 
                 7.50 
                 565 
                 24 
                  6.53 
                  857 
                 37 
               
               
                 October 
                 6.97 
                 606 
                 24 
                  5.82 
                  977 
                 37 
               
               
                 November 
                 7.19 
                 240 
                 24 
                  8.65 
                  953 
                 37 
               
               
                 December 
                 5.85 
                 624 
                 24 
                 15.37 
                  720 
                 37 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                   
                 Study 1 
                 Study 2 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Average 
                   
                   
                 Average 
                   
                   
               
               
                   
                 (μg Fel d1/ml 
                 Number of 
                 Number of 
                 (μg Fel d1/ml 
                 Number of 
                 Number of 
               
               
                   
                 of saliva) 
                 measures 
                 cats 
                 of saliva) 
                 measures 
                 cats 
               
               
                   
               
               
                 January 
                 6.50 
                 295 
                 24 
                 12.68 
                 461 
                 37 
               
               
                 February 
                 5.51 
                 264 
                 16 
                 12.13 
                 465 
                 37 
               
               
                 March 
                 4.76 
                 208 
                 16 
                  8.30 
                 443 
                 37 
               
               
                 April 
                 5.04 
                 271 
                 23 
                  8.11 
                 465 
                 37 
               
               
                 May 
                 6.63 
                 479 
                 26 
                  7.12 
                 479 
                 37 
               
               
                 June 
                 7.25 
                 302 
                 24 
                  7.35 
                 477 
                 37 
               
               
                 July 
                 8.02 
                 306 
                 24 
                  8.16 
                 454 
                 37 
               
               
                 August 
                 7.89 
                 318 
                 24 
                  6.08 
                 506 
                 37 
               
               
                 September 
                 8.32 
                 283 
                 24 
                  6.82 
                 432 
                 37 
               
               
                 October 
                 7.69 
                 303 
                 24 
                  6.63 
                 496 
                 37 
               
               
                 November 
                 7.70 
                 120 
                 24 
                  9.05 
                 486 
                 37 
               
               
                 December 
                 6.24 
                 312 
                 24 
                 17.55 
                 354 
                 37 
               
               
                   
               
            
           
         
       
     
     As shown in Table 5 and 6, the expression of Fel d1 varied monthly. In one aspect, the higher expression time period can be from November to February. In another aspect, the high expression time period can be from July to September. Additionally, individual expressions for each cat is shown in Table 7 and 8, shown in μg/ml (microgram Fel d1 per ml of saliva). Saliva data (μg Fel d1/ml of saliva) collected twice daily every other day over a year from Study 1 and Study 2 is presented in table 7. Saliva data (μg Fel d1/ml of saliva) collected once daily every other day over a year from Study 1 and Study 2 is presented in table 8. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 7 
               
               
                   
                   
               
               
                   
                   
                 Average 
               
               
                   
                 Cat ID 
                 (μg/ml) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Cat #1 
                 0.36 
               
               
                   
                 Cat #2 
                 0.49 
               
               
                   
                 Cat #3 
                 1.02 
               
               
                   
                 Cat #4 
                 1.08 
               
               
                   
                 Cat #5 
                 1.14 
               
               
                   
                 Cat #6 
                 1.20 
               
               
                   
                 Cat #7 
                 1.24 
               
               
                   
                 Cat #8 
                 1.52 
               
               
                   
                 Cat #9 
                 1.61 
               
               
                   
                 Cat #10 
                 1.74 
               
               
                   
                 Cat #11 
                 2.11 
               
               
                   
                 Cat #12 
                 2.11 
               
               
                   
                 Cat #13 
                 2.53 
               
               
                   
                 Cat #14 
                 2.54 
               
               
                   
                 Cat #15 
                 2.58 
               
               
                   
                 Cat #16 
                 3.01 
               
               
                   
                 Cat #17 
                 3.30 
               
               
                   
                 Cat #18 
                 3.44 
               
               
                   
                 Cat #19 
                 3.88 
               
               
                   
                 Cat #20 
                 3.95 
               
               
                   
                 Cat #21 
                 3.98 
               
               
                   
                 Cat #22 
                 3.99 
               
               
                   
                 Cat #23 
                 4.16 
               
               
                   
                 Cat #24 
                 4.17 
               
               
                   
                 Cat #25 
                 4.22 
               
               
                   
                 Cat #26 
                 4.24 
               
               
                   
                 Cat #27 
                 4.36 
               
               
                   
                 Cat #28 
                 4.46 
               
               
                   
                 Cat #29 
                 4.54 
               
               
                   
                 Cat #30 
                 4.64 
               
               
                   
                 Cat #31 
                 4.95 
               
               
                   
                 Cat #32 
                 5.04 
               
               
                   
                 Cat #33 
                 5.29 
               
               
                   
                 Cat #34 
                 5.72 
               
               
                   
                 Cat #35 
                 5.76 
               
               
                   
                 Cat #36 
                 6.42 
               
               
                   
                 Cat #37 
                 6.50 
               
               
                   
                 Cat #38 
                 6.62 
               
               
                   
                 Cat #39 
                 6.68 
               
               
                   
                 Cat #40 
                 6.80 
               
               
                   
                 Cat #41 
                 7.29 
               
               
                   
                 Cat #42 
                 7.87 
               
               
                   
                 Cat #43 
                 8.04 
               
               
                   
                 Cat #44 
                 8.20 
               
               
                   
                 Cat #45 
                 8.71 
               
               
                   
                 Cat #46 
                 8.50 
               
               
                   
                 Cat #47 
                 9.36 
               
               
                   
                 Cat #48 
                 9.27 
               
               
                   
                 Cat #49 
                 9.28 
               
               
                   
                 Cat #50 
                 9.38 
               
               
                   
                 Cat #51 
                 11.07 
               
               
                   
                 Cat #52 
                 11.44 
               
               
                   
                 Cat #53 
                 11.78 
               
               
                   
                 Cat #54 
                 11.87 
               
               
                   
                 Cat #55 
                 14.19 
               
               
                   
                 Cat #56 
                 15.02 
               
               
                   
                 Cat #57 
                 14.80 
               
               
                   
                 Cat #58 
                 16.61 
               
               
                   
                 Cat #59 
                 17.11 
               
               
                   
                 Cat #60 
                 18.34 
               
               
                   
                 Cat #61 
                 20.47 
               
               
                   
                 Cat #62 
                 21.99 
               
               
                   
                 Cat #63 
                 23.36 
               
               
                   
                 Cat #64 
                 35.04 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                 TABLE 8 
               
               
                   
                   
               
               
                   
                   
                 Average 
               
               
                   
                 Cat ID 
                 (μg/ml) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Cat #1 
                 0.37 
               
               
                   
                 Cat #2 
                 0.50 
               
               
                   
                 Cat #3 
                 1.10 
               
               
                   
                 Cat #4 
                 1.10 
               
               
                   
                 Cat #5 
                 1.28 
               
               
                   
                 Cat #6 
                 1.38 
               
               
                   
                 Cat #7 
                 1.38 
               
               
                   
                 Cat #8 
                 1.64 
               
               
                   
                 Cat #9 
                 1.72 
               
               
                   
                 Cat #10 
                 1.88 
               
               
                   
                 Cat #11 
                 2.03 
               
               
                   
                 Cat #12 
                 2.13 
               
               
                   
                 Cat #13 
                 2.70 
               
               
                   
                 Cat #14 
                 2.59 
               
               
                   
                 Cat #15 
                 2.55 
               
               
                   
                 Cat #16 
                 3.01 
               
               
                   
                 Cat #17 
                 3.35 
               
               
                   
                 Cat #18 
                 3.70 
               
               
                   
                 Cat #19 
                 4.20 
               
               
                   
                 Cat #20 
                 4.57 
               
               
                   
                 Cat #21 
                 4.03 
               
               
                   
                 Cat #22 
                 4.07 
               
               
                   
                 Cat #23 
                 4.54 
               
               
                   
                 Cat #24 
                 4.42 
               
               
                   
                 Cat #25 
                 4.32 
               
               
                   
                 Cat #26 
                 4.48 
               
               
                   
                 Cat #27 
                 4.63 
               
               
                   
                 Cat #28 
                 4.83 
               
               
                   
                 Cat #29 
                 5.05 
               
               
                   
                 Cat #30 
                 4.80 
               
               
                   
                 Cat #31 
                 5.42 
               
               
                   
                 Cat #32 
                 5.42 
               
               
                   
                 Cat #33 
                 5.60 
               
               
                   
                 Cat #34 
                 5.90 
               
               
                   
                 Cat #35 
                 5.50 
               
               
                   
                 Cat #36 
                 6.91 
               
               
                   
                 Cat #37 
                 6.57 
               
               
                   
                 Cat #38 
                 7.49 
               
               
                   
                 Cat #39 
                 7.61 
               
               
                   
                 Cat #40 
                 6.59 
               
               
                   
                 Cat #41 
                 7.85 
               
               
                   
                 Cat #42 
                 7.23 
               
               
                   
                 Cat #43 
                 8.33 
               
               
                   
                 Cat #44 
                 8.81 
               
               
                   
                 Cat #45 
                 8.84 
               
               
                   
                 Cat #46 
                 9.29 
               
               
                   
                 Cat #47 
                 11.41 
               
               
                   
                 Cat #48 
                 11.91 
               
               
                   
                 Cat #49 
                 10.92 
               
               
                   
                 Cat #50 
                 10.56 
               
               
                   
                 Cat #51 
                 12.59 
               
               
                   
                 Cat #52 
                 12.45 
               
               
                   
                 Cat #53 
                 12.11 
               
               
                   
                 Cat #54 
                 15.60 
               
               
                   
                 Cat #55 
                 15.26 
               
               
                   
                 Cat #56 
                 17.60 
               
               
                   
                 Cat #57 
                 15.77 
               
               
                   
                 Cat #58 
                 18.20 
               
               
                   
                 Cat #59 
                 17.67 
               
               
                   
                 Cat #60 
                 19.71 
               
               
                   
                 Cat #61 
                 23.22 
               
               
                   
                 Cat #62 
                 24.34 
               
               
                   
                 Cat #63 
                 25.20 
               
               
                   
                 Cat #64 
                 42.45 
               
               
                   
                   
               
            
           
         
       
     
     As shown in Tables 7 and 8, felines produce Fel d1 in varying amounts. As such, low, medium, and high Fel d1 producers can be quantified. Low Fel d1 producers can include felines that produce Fel d1 in an amount ranging from 0.01 to 5 micrograms per ml of saliva (μg/ml). Medium Fel d1 producers can include felines that produce Fel d1 in an amount ranging from between 5 and 10 micrograms per ml of saliva (μg/ml). High Fel d1 producers can include felines that produce Fel d1 in an amount from 10 to 100 micrograms per ml of saliva (μg/ml). Felines producing more than 100 micrograms per ml of saliva can also be deemed high Fel d1 producers. 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.