§ 3.6 Primary enclosures. Primary enclosures for dogs and cats must meet the following minimum requirements: ( a ) *General requirements.* ( 1 ) Primary enclosures must be designed and constructed of suitable materials so that they are structurally sound. The primary enclosures must be kept in good repair.
( 2 ) Primary enclosures must be constructed and maintained so that they: ( i ) Have no sharp points or edges that could injure the dogs and cats;
( ii ) Protect the dogs and cats from injury;
( iii ) Contain the dogs and cats securely;
( iv ) Keep other animals from entering the enclosure;
( v ) Enable the dogs and cats to remain dry and clean;
( vi ) Provide shelter and protection from extreme temperatures and weather conditions that may be uncomfortable or hazardous to all the dogs and cats;
( vii ) Provide sufficient shade to shelter all the dogs and cats housed in the primary enclosure at one time;
( viii ) Provide all the dogs and cats with easy and convenient access to clean food and water;
( ix ) Enable all surfaces in contact with the dogs and cats to be readily cleaned and sanitized in accordance with § 3.11(b) of this subpart, or be replaceable when worn or soiled;
( x ) Have floors that are constructed in a manner that protects the dogs' and cats' feet and legs from injury, and that, if of mesh or slatted construction, do not allow the dogs' and cats' feet to pass through any openings in the floor;
( xi ) Provide sufficient space to allow each dog and cat to turn about freely, to stand, sit, and lie in a comfortable, normal position, and to walk in a normal manner; and
( xii ) If the suspended floor of a primary enclosure is constructed of metal strands, the strands must either be greater than 1 ⁄ 8 of an inch in diameter (9 gauge) or coated with a material such as plastic or fiberglass. The suspended floor of any primary enclosure must be strong enough so that the floor does not sag or bend between the structural supports.
( b ) *Additional requirements for cats* — ( 1 ) *Space.* Each cat, including weaned kittens, that is housed in any primary enclosure must be provided minimum vertical space and floor space as follows: ( i ) Each primary enclosure housing cats must be at least 24 in. high (60.96 cm);
( ii ) Cats up to and including 8.8 lbs (4 kg) must be provided with at least 3.0 ft2 (0.28 m2);
( iii ) Cats over 8.8 lbs (4 kg) must be provided with at least 4.0 ft2 (0.37 m2);
( iv ) Each queen with nursing kittens must be provided with an additional amount of floor space, based on her breed and behavioral characteristics, and in accordance with generally accepted husbandry practices. If the additional amount of floor space for each nursing kitten is equivalent to less than 5 percent of the minimum requirement for the queen, such housing must be approved by the attending veterinarian in the case of a research facility, and, in the case of dealers and exhibitors, such housing must be approved by the Administrator; and
( v ) The minimum floor space required by this section is exclusive of any food or water pans. The litter pan may be considered part of the floor space if properly cleaned and sanitized.
( 2 ) *Compatibility.* All cats housed in the same primary enclosure must be compatible, as determined by observation. Not more than 12 adult nonconditioned cats may be housed in the same primary enclosure. Queens in heat may not be housed in the same primary enclosure with sexually mature males, except for breeding. Except when maintained in breeding colonies, queens with litters may not be housed in the same primary enclosure with other adult cats, and kittens under 4 months of age may not be housed in the same primary enclosure with adult cats, other than the dam or foster dam. Cats with a vicious or aggressive disposition must be housed separately.
( 3 ) *Litter.* In all primary enclosures, a receptacle containing sufficient clean litter must be provided to contain excreta and body wastes.
( 4 ) *Resting surfaces.* Each primary enclosure housing cats must contain a resting surface or surfaces that, in the aggregate, are large enough to hold all the occupants of the primary enclosure at the same time comfortably. The resting surfaces must be elevated, impervious to moisture, and be able to be easily cleaned and sanitized, or easily replaced when soiled or worn. Low resting surfaces that do not allow the space under them to be comfortably occupied by the animal will be counted as part of the floor space.
( 5 ) *Cats in mobile or traveling shows or acts.* Cats that are part of a mobile or traveling show or act may be kept, while the show or act is traveling from one temporary location to another, in transport containers that comply with all requirements of § 3.15 other than the marking requirements in § 3.15(a)(6). When the show or act is not traveling, the cats must be placed in primary enclosures that meet the minimum requirements of this section.
( c ) *Additional requirements for dogs* — ( 1 ) *Space.* ( i ) Each dog housed in a primary enclosure (including weaned puppies) must be provided a minimum amount of floor space, calculated as follows: Find the mathematical square of the sum of the length of the dog in inches (measured from the tip of its nose to the base of its tail) plus 6 inches; then divide the product by 144. The calculation is: (length of dog in inches + 6) × (length of dog in inches + 6) = required floor space in square inches. Required floor space in inches/144 = required floor space in square feet.
( ii ) Each bitch with nursing puppies must be provided with an additional amount of floor space, based on her breed and behavioral characteristics, and in accordance with generally accepted husbandry practices as determined by the attending veterinarian. If the additional amount of floor space for each nursing puppy is less than 5 percent of the minimum requirement for the bitch, such housing must be approved by the attending veterinarian in the case of a research facility, and, in the case of dealers and exhibitors, such housing must be approved by the Administrator.
( iii ) The interior height of a primary enclosure must be at least 6 inches higher than the head of the tallest dog in the enclosure when it is in a normal standing position: *Provided* That, prior to February 15, 1994, each dog must be able to stand in a comfortable normal position.
( 2 ) *Compatibility.* All dogs housed in the same primary enclosure must be compatible, as determined by observation. Not more than 12 adult nonconditioned dogs may be housed in the same primary enclosure. Bitches in heat may not be housed in the same primary enclosure with sexually mature males, except for breeding. Except when maintained in breeding colonies, bitches with litters may not be housed in the same primary enclosure with other adult dogs, and puppies under 4 months of age may not be housed in the same primary enclosure with adult dogs, other than the dam or foster dam. Dogs with a vicious or aggressive disposition must be housed separately.
( 3 ) *Dogs in mobile or traveling shows or acts.* Dogs that are part of a mobile or traveling show or act may be kept, while the show or act is traveling from one temporary location to another, in transport containers that comply with all requirements of § 3.15 other than the marking requirements in § 3.15(a)(6). When the show or act is not traveling, the dogs must be placed in primary enclosures that meet the minimum requirements of this section.
( 4 ) *Prohibited means of primary enclosure.* Permanent tethering of dogs is prohibited for use as primary enclosure. Temporary tethering of dogs is prohibited for use as primary enclosure unless approval is obtained from APHIS.
( d ) Innovative primary enclosures not precisely meeting the floor area and height requirements provided in paragraphs (b)(1) and (c)(1) of this section, but that provide the dogs or cats with a sufficient volume of space and the opportunity to express species-typical behavior, may be used at research facilities when approved by the Committee, and by dealers and exhibitors when approved by the Administrator.
(Approved by the Office of Management and Budget under control number 0579-0093) [56 FR 6486, Feb. 15, 1991, as amended at 62 FR 43275, Aug. 13, 1997; 63 FR 3023, Jan. 21, 1998; 63 FR 37482, July 13, 1998; 83 FR 25555, June 4, 2018; 85 FR 28798, May 13, 2020]