Patent Description:
If the cat can be induced to drink more, this can dilute the urine and thereby ameliorate feline urinary conditions resulting from low hydration. This dilution acts at two levels: first, by reducing the electrolyte concentration in the urine (assuming the cat is not drinking more simply to compensate for higher dietary salt), and then by increasing micturition frequency and therefore reducing the amount of time spent by the urine in the bladder. Cats generally drink only about <NUM> millilitres of water per kilo of body weight per day, and it is difficult to increase spontaneous drinking. Providing moist food helps to increase water intake in an animal that does not drink very much, but it is not sufficient, either because there is still not enough water ingested or because it does not sufficiently increase diuresis. In addition, cats exhibiting a urological syndrome are often obese or carry excess weight. Thus, when it is desired to treat urinary disorders, and in particular FLUTD, providing a moist food may be preferable, but it is not sufficient, i.e., the food does not provide sufficient hydration, may not be accepted by the cat, or even may induce an additional excess weight and/or obesity if the amount distributed is poorly controlled.

Certain cat foods which contain certain omega-<NUM> polyunsaturated fatty acids such as docosahexaenoic acid ("DHA") and eicosapentaenoic acid ("EPA") are known, e.g., as disclosed in <CIT>. Certain cat foods are also known to contain both omega-<NUM> and omega-<NUM> polyunsaturated in particular amounts and ratios such as disclosed in <CIT>. However, there is no disclosure in the prior art of any effect of such fatty acids in the diet on hydration. Information on single nucleotide polymorphisms (SNPs) in cats is provided by the "Feline Genome Project" (www. edu/Catgenetics/Feline Genome Project/FGP_GR_Markers.

Therefore, there exists today a need for methods and compositions to increase hydration in cats, thereby treating, reducing, inhibiting or ameliorating urinary conditions such as FLUTD.

It has been surprisingly discovered that controlling the ratio of certain omega-<NUM> and omega-<NUM> polyunsaturated fatty acids in cat food will result in increased hydration of cats, in particular, the ratio of arachidonic acid ("AA") to EPA. We have found that a high AA to EPA ratio increases urine flow as measured by urine specific gravity in both young and mature adult cats without dehydrating the animal. Blood osmolity indicates that the animals have increased hydration, most likely through increased water intake.

Our studies measured the effect of diets having high vs. low ratios of AA:EPA on both urine specific gravity and relative super saturation (RSS). A high RSS means that a stone is more likely to form (more solutes with which to form stones). Urine specific gravity is positively correlated to (RSS). Cats receiving the high AA:EPA foods had lower urine specific gravity and an improved (lowered) RSS, corresponding to a reduced risk of stone formation.

The present invention concerns the use of a diagnostic kit for identifying a cat as being at elevated risk of developing a disease or condition results from low hydration, as defined in the claims. The kit comprises a sequence specific oligonucleotide probe which recognizes one or more SNPs selected from chrB4. <NUM>, chrB4. <NUM>, and chrB4.

The level of hydration in a cat can be improved by feeding the cat a food comprising arachidonic acid and eicosapentaenoic acid wherein the ratio of arachidonic acid to eicosapentaenoic acid is <NUM>:<NUM> or greater and the amount of arachidonic acid is <NUM> to <NUM>% dry weight. A disease or condition in a cat resulting from low hydration can be treated by feeding the cat a food containing arachidonic acid and eicosapentaenoic acid wherein the ratio of arachidonic acid to eicosapentaenoic acid is <NUM>:<NUM> or greater and the amount of arachidonic acid is <NUM> to <NUM>% dry weight.

The cat food can be a palatable, nutritionally complete cat food composition comprising arachidonic acid and eicosapentaenoic acid in an amount effective to improve the hydration in a cat, wherein the food composition, together with water, is palatable and nutritionally complete as a sole diet for the cat, and wherein the ratio of arachidonic acid to eicosapentaenoic acid, on a dry weight basis, is <NUM>:<NUM> or greater, and the ratio, on a dry weight basis, of omega-<NUM> fatty acids to omega-<NUM> fatty acids in the composition is <NUM>:<NUM> to less than <NUM>:<NUM>.

It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention, which is only defined by the claims.

The following description is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

All percentages expressed herein are on a weight by dry matter basis unless specifically stated otherwise.

In the context of the invention, the term "treating" or "treatment", as used herein, means reversing, alleviating, mitigating or inhibiting the progress of the disorder or condition to which such term applies, or one or more symptoms of such disorder or condition. As used herein and in the appended claims, the singular forms "a", "an", and "the" include plural reference unless the context clearly dictates otherwise.

Urine specific gravity is a measurement of urine dilution. The higher the specific gravity value the more dense/concentrated the urine is. The normal range for urine specific gravity in a cat is typically between <NUM> and <NUM>. A very low specific gravity is indicative of renal failure, whereas a high urine specific gravity means that the urine is more concentrated and therefore it is more likely that stones will precipitate and cause problems.

Urine specific gravity is regulated by a combination of (a) urine production through glomerular filtration into the collecting ducts of the kidney and (b) resorption of water from the collecting duct to go back in to the blood stream. This process is in part regulated by the eicosanoid prostaglandin E2 (PGE2). PGE2 binds to prostaglandin E receptors on the kidney tubular cell and through activation of second messengers, regulates the water and sodium channels that regulate water and sodium balance in the body.

The inventors have discovered a genetic locus containing the prostaglandin E synthase <NUM> gene, a key enzyme in the pathway that makes PGE2 from AA, using a whole genome association study between the genotypes of cats and their individual urine specific gravity. Furthermore ,it has been discovered that different ratios of AA (the precursor for PGE2) to EPA in the diet of cats correlate with their urine specific gravities. Thus, it has been discovered that regulating the amount of AA in the diet can lower urine specific gravity in cats. It also has been found that even though the urine is more dilute in cats fed the composition of the invention, their blood osmolality is also decreased indicating that these animals are drinking more water and that their overall water balance is increased, i.e., they are more hydrated.

A high relative super saturation ("RSS") is indicative of a propensity to form urine stones, for both oxalate and struvite stones. It has been discovered that a decline in specific gravity is correlated to a decline in RSS. Therefore, the biological benefit of a more hydrated urine in cats is a reduced risk of stone formation.

The cat food compositions described herein can be nutritionally complete cat food compositions. A nutritionally complete composition provides a diet that includes sufficient nutrients for maintenance of normal health of a healthy cat. A nutritionally complete composition is palatable and, together with water, provides the sole source of all of the nutrition necessary for maintenance of normal health in a healthy cat. Nutritionally complete compositions are familiar to one of skill in the art. For example, nutrients and ingredients such as those disclosed herein as well as others suitable for animal feed compositions, and recommended amounts thereof, may be found, for example, in the Official Publication of the Associate of American Feed Control Officials ("AAFCO"), Inc. , Nutrient Requirements of Dogs and Cats, <NUM>. For example, nutritionally complete foods may contain protein, fat, carbohydrate, dietary fiber, amino acids, minerals, vitamins, and other ingredients in amounts known by those of skill in the art.

Protein may be supplied by any of a variety of sources known by those skilled in the art, including plant sources, animal sources, or both. Animal sources include, for example, meat, meat by-products, seafood, dairy, eggs, etc. Meats include, for example, the flesh of poultry, fish, and mammals (e.g., cattle, pigs, sheep, goats, and the like). Meat by-products include, for example, lungs, kidneys, brain, livers, and stomachs and intestines (freed of all or essentially all their contents). The protein can be intact, almost completely hydrolyzed, or partially hydrolyzed. Typical protein amounts in the composition of the invention are at least about <NUM>% (or from about <NUM>% to about <NUM>%, or from about <NUM>% to about <NUM>%, or from about <NUM>% to about <NUM>%).

Fat can be supplied by any of a variety of sources known by those skilled in the art, including meat, meat by-products, fish oil, and plants. Plant fat sources include wheat, flaxseed, rye, barley, rice, sorghum, corn, oats, millet, wheat germ, corn germ, soybeans, peanuts, and cottonseed, as well as oils derived from these and other plant fat sources. The compositions of the invention typically contain at least about <NUM>% (or from about <NUM>% to about <NUM>%, or from about <NUM>% to about <NUM>%, or from about <NUM>% to about <NUM>%) total fat.

AA may be provided from a variety of natural sources. Liver, e.g., chicken liver, is relatively high in AA. Fish oil, on the other hand, is relatively high in EPA, thus not adding fish oil is preferred to avoid high AA:EPA ratios. In addition to AA and EPA, fatty acids which may be included as part of the fat component in the compositions of the present invention include other omega-<NUM> and omega-<NUM> fatty acids such as DHA, alpha-linolenic acid, gamma-linolenic acid, linoleic acid, octadecatetraenoic acid (stearidonic acid), or mixtures thereof. The ratio, on a dry weight basis, of omega-<NUM> to omega-<NUM> fatty acids in the compositions of the invention is typically <NUM>:<NUM> or greater, in another embodiment at least <NUM>:<NUM> to less than <NUM>:<NUM>, in another embodiment about <NUM>:<NUM> to <NUM>:<NUM>, in another embodiment about <NUM>:<NUM> to <NUM>:<NUM>.

Carbohydrate may be supplied by any of a variety of sources known by those skilled in the art, including oat fiber, cellulose, peanut hulls, beet pulp, parboiled rice, corn starch, corn gluten meal, and any combination of those sources. Grains supplying carbohydrate include, but are not limited to, wheat, corn, barley, and rice. Carbohydrate content of foods may be determined by any number of methods known by those of skill in the art. Generally, carbohydrate percentage may be calculated as nitrogen free extract ("NFE"), which may be calculated as follows: NFE=<NUM>%-moisture %-protein %-fat %-ash %-crude fiber %.

Dietary fiber refers to components of a plant which are resistant to digestion by an animal's digestive enzymes. Dietary fiber includes soluble and insoluble fibers. Soluble fiber are resistant to digestion and absorption in the small intestine and undergo complete or partial fermentation in the large intestine, e.g., beet pulp, guar gum, chicory root, psyllium, pectin, blueberry, cranberry, squash, apples, oats, beans, citrus, barley, or peas. Insoluble fiber may be supplied by any of a variety of sources, including cellulose, whole wheat products, wheat oat, corn bran, flax seed, grapes, celery, green beans, cauliflower, potato skins, fruit skins, vegetable skins, peanut hulls, and soy fiber. Crude fiber includes indigestible components contained in cell walls and cell contents of plants such as grains, e.g., hulls of grains such as rice, corn, and beans. Typical fiber amounts in the composition of the invention are from about <NUM> to <NUM>%, or about1% to about <NUM>%.

Amino acids, including essential amino acids, may be added to the compositions of the present invention as free amino acids, or supplied by any number of sources, e.g., crude protein, to the compositions of the present invention. Essential amino acids are amino acids that cannot be synthesized de novo, or in sufficient quantities by an organism and thus must be supplied in the diet. Essential amino acids vary from species to species, depending upon the organism's metabolism. For example, it is generally understood that the essential amino acids for dogs and cats (and humans) are phenylalanine, leucine, methionine, lysine, isoleucine, valine, threonine, tryptophan, histidine and arginine. In addition, taurine, while technically not an amino acid but a derivative of cysteine, is an essential nutrient for cats.

The cat food compositions described herein may also contain one or more minerals and/or trace elements, e.g., calcium, phosphorus, sodium, potassium, magnesium, manganese, copper, zinc, choline, or iron salts, in amounts required to avoid deficiency and maintain health. These amounts are known by those of skill in the art, for example, as provided in the Official Publication of the Associate of American Feed Control Officials, Inc. ("AAFCO"), Nutrient Requirements of Dogs and Cats, <NUM>. Typical mineral amounts are about <NUM> to about <NUM>% or about <NUM>% to about <NUM>%.

The cat food compositions described herein may also include vitamins in amounts required to avoid deficiency and maintain health. These amounts, and methods of measurement are known by those skilled in the art. For example, the Official Publication of the Associate of American Feed Control Officials, Inc. ("AAFCO"), Nutrient Requirements of Dogs and Cats, <NUM> provides recommended amounts of such ingredients for dogs and cats. As contemplated herein, useful vitamins may include, but are not limited to, vitamin A, vitamin B. <NUM>, vitamin B. <NUM>, vitamin B. <NUM>, vitamin B. <NUM>, vitamin C, vitamin D, vitamin E, vitamin H (biotin), vitamin K, folic acid, inositol, niacin, and pantothenic acid. Typical vitamin amounts in the composition of the invention are about from <NUM> to about <NUM>% or about <NUM>% to about <NUM>%.

The cat food compositions described herein may additionally comprise other additives such as palatability enhancers and stabilizers in amounts and combinations familiar to one of skill in the art. Stabilizing substances include, for example, substances that tend to increase the shelf life of the composition. Other examples of other such additive potentially suitable for inclusion in the compositions of the invention include, for example, preservatives, colorants, antioxidants, flavorants, synergists and sequestrants, packaging gases, stabilizers, emulsifiers, thickeners, gelling agents, and humectants. Examples of emulsifiers and/or thickening agents include, for example, gelatin, cellulose ethers, starch, starch esters, starch ethers, and modified starches. The concentration of such additives in the composition typically may be up to about <NUM>% by weight. In some embodiments, the concentration of such additives (particularly where such additives are primarily nutritional balancing agents, such as vitamins and minerals) is from about <NUM>% to about <NUM>% by weight. In some embodiments, the concentration of such additives (again, particularly where such additives are primarily nutritional balancing agents) is from about <NUM>% to about <NUM>% by weight.

Cat foods can have any consistency or moisture content, e.g., the cat food compositions described herein may be, for example, a dry, moist or semi-moist animal food composition. For instance, the moisture content can be from about <NUM>% to about <NUM>% of the total weight of the composition. "Semi-moist" refers to a food composition containing from about <NUM> to about <NUM>% moisture. "Moist" food refers to a food composition that has a moisture content of about <NUM> to <NUM>% or greater. "Dry" food refers to a food composition with about <NUM> to about <NUM>% moisture content and is often manufactured in the form of small bits or kibbles.

In preparing a cat food composition as described herein in wet or canned form, any ingredient (e.g., AA, EPA) generally may, for example, be incorporated into the composition during the processing of the formulation, such as during and/or after mixing of other components of the composition. Distribution of these components into the composition can be accomplished by conventional means. For example, ground animal and poultry proteinaceous tissues are mixed with the other ingredients, including fish oils, cereal grains, other nutritionally balancing ingredients, special-purpose additives (e.g., vitamin and mineral mixtures, inorganic salts, cellulose and beet pulp, bulking agents, and the like); and water that is sufficient for processing is also added. These ingredients preferably are mixed in a vessel suitable for heating while blending the components. Heating of the mixture may be effected using any suitable manner, such as, for example, by direct steam injection or by using a vessel fitted with a heat exchanger. Following the addition of the last ingredient, the mixture is heated to a temperature range of from about <NUM>° F. ) to about <NUM>° F. In some embodiments, the mixture is heated to a temperature range of from about <NUM>° F. ) to about <NUM>° F. Temperatures outside these ranges are generally acceptable, but may be commercially impractical without use of other processing aids. When heated to the appropriate temperature, the material will typically be in the form of a thick liquid. The thick liquid is filled into cans. A lid is applied, and the container is hermetically sealed. The sealed can is then placed into conventional equipment designed to sterilize the contents. This is usually accomplished by heating to temperatures of greater than about <NUM>° F. ) for an appropriate time, which is dependent on, for example, the temperature used and the composition.

Cat food compositions can alternatively be prepared in a dry form using conventional processes. Typically, dry ingredients, including, for example, animal protein, plant protein, grains, etc., are ground and mixed together. Moist or liquid ingredients, including fats, oils, animal protein, water, etc., are then added to and mixed with the dry mix. The mixture is then processed into kibbles or similar dry pieces. Kibble is often formed using an extrusion process in which the mixture of dry and wet ingredients is subjected to mechanical work at a high pressure and temperature, and forced through small openings and cut off into kibble by a rotating knife. The wet kibble is then dried and optionally coated with one or more topical coatings which may include, for example, flavors, fats, oils, powders, and the like. Kibble also can be made from the dough using a baking process, rather than extrusion, wherein the dough is placed into a mold before dry-heat processing.

The cat food composition for hydrating cats or for treating a disease or condition in cats described herein can be a nutritionally complete cat food or the necessary amounts and ratios of AA and EPA can be administered separately, e.g., as separate ingredient or as part of a separate ingredient, typically as a supplement, so that the total diet consumed meets the amounts and ratios of AA and EPA necessary to result in the beneficial effects of the invention. The treated disease or condition can be, for example, development of urinary stones in a cat, feline idiopathic cystitis, or FLUTD.

A method of improving the level of hydration in a cat can comprise providing the cat with a diet comprising an effective amount of arachidonic acid, wherein the diet comprises a greater amount of arachidonic acid than eicosapentaenoic acid (Method <NUM>). For example, such method may be a method wherein (a) the diet consists of water and a cat food composition which is palatable and nutritionally complete for a cat, the cat food composition comprising arachidonic acid and eicosapentaenoic acid, wherein the ratio of arachidonic acid to eicosapentaenoic acid is <NUM>:<NUM> or greater, e.g., at least <NUM>:<NUM>, e.g., at least <NUM>:<NUM>, and the amount of arachidonic acid in the composition is <NUM> to <NUM>% dry weight, or (b) the diet comprises an effective amount of a supplement comprising arachidonic acid together with a nutritionally complete cat food. In such method, the diet may comprise omega-<NUM> and omega-<NUM> fatty acids in a weight ratio, on a dry basis, of <NUM>:<NUM> or greater, for example, in ratio between <NUM>:<NUM> and <NUM>:<NUM>, e.g., <NUM>:<NUM> to <NUM>:<NUM>. In such methods, the cat can be an adult cat, and/or a male cat. Said methods can be methods of treating a disease or condition in a cat resulting from low hydration, wherein the cat is in need of such treatment, wherein the disease or condition is, for example, selected from development of urinary stones (including bladder stones or kidney stones), feline idiopathic cystitis, and FLUTD, and/or wherein the cat has been identified being at elevated risk of developing a disease or condition resulting from low hydration, e.g., a disease or condition selected from development of urinary stones (including bladder stones or kidney stones), feline idiopathic cystitis, and FLUTD, wherein the risk is assessed by (a) measuring the cat's urine specific gravity, and a cat having a urine specific gravity of at least <NUM>, e.g. greater than <NUM>, e.g. greater than <NUM>, is considered to be at elevated risk, and/or (b) wherein the cat expresses a SNP or a mutation in the PTGES3 gene associated with elevated risk. In such methods, the cat can be identified as being at elevated risk based on exhibiting of one or more single nucleotide polymorphisms (SNPs) selected from chrB4. <NUM>, chrB4. <NUM> and chrB4. <NUM>, and/or can be a cat having an initial urine specific gravity greater than <NUM>, e.g., greater than <NUM>. After one month of practice of such method, e.g., after three months, e.g., after six months, the cat's urine specific gravity may be reduced relative to the cat's initial urine specific gravity, e.g., to less than <NUM>. The cat can have a mutation in the PTGES3 gene and/or exhibit one or more single nucleotide polymorphisms (SNPs) selected from chrB4. <NUM>, chrB4. <NUM> and chrB4. The cat may remain on the diet for at least a month, e.g., at least three months, e.g., at least six months. The improved hydration in the cat can be measured as a decrease in urine specific gravity and/or as a decrease in blood osmolality. The method of improving the level of hydration in a cat as described herein may cause an increase in the level of prostaglandin E2. The cat receiving the diet in accordance with the method described herein may exhibit increased water intake but not increased sodium chloride intake. The cat receiving the diet may be at least <NUM> years old, e.g., at least <NUM> years old. The cat's diet may comprise a Composition <NUM>, as set forth below.

A useful cat food composition comprises arachidonic acid and eicosapentaenoic acid in an amount effective to improve the hydration in a cat, wherein the food, together with water, is palatable and nutritionally complete as a sole diet for the cat, and wherein the ratio of arachidonic acid to eicosapentaenoic acid, on a dry weight basis, is <NUM>:<NUM> or greater, and the ratio, on a dry basis, of omega-<NUM> fatty acids to omega-<NUM> fatty acids in the composition is <NUM>:<NUM> to less than <NUM>:<NUM> (Composition <NUM>). For example, such composition may comprise an amount of arachidonic acid of <NUM> to <NUM>% dry weight, and/or at least <NUM>% e.g., at least <NUM>%, of poultry liver, e.g., chicken liver, dry weight, and less than <NUM>% fish oil, dry weight. Such compositions may comprise ingredients substantially as set forth for Diet B of Example <NUM> below, wherein by "substantially as set forth" is meant that each listed ingredient is present in the composition an amount of ± <NUM>%, e.g., ± <NUM>% of the amount as set forth, on a dry weight basis. The foregoing compositions can be in the form of a dry food, e.g., a kibble product. Composition <NUM> can be used in a Method <NUM> as described above.

Arachidonic acid, or an ingredient or composition comprising arachidonic acid, e.g. Composition <NUM>, as described above, can be used for improving the level of hydration in a cat, e.g., for a Method <NUM>, as described above.

Arachidonic acid, or an ingredient or composition comprising arachidonic acid, can be used in the manufacture of a cat food composition for use in a Method <NUM>, das described above.

In methods for identifying cats at elevated risk of developing a disease or condition resulting from low hydration, e.g., a disease or condition selected from development of urinary stones (including bladder stones or kidney stones), feline idiopathic cystitis, and FLUTD, e.g., the risk can be assessed by (a) measuring the cat's urine specific gravity, and a cat having a urine specific gravity of at least <NUM>, e.g. greater than <NUM>, e.g. greater than <NUM>, is considered to be at elevated risk, and/or (b) wherein the cat expresses a SNP or a mutation in the PTGES3 gene associated with elevated risk.

According to the present invention, the cat identified as being at elevated risk based on exhibiting of one or more single nucleotide polymorphisms (SNPs) selected from chrB4. <NUM>, chrB4. <NUM> and chrB4. Whether a cat has one of these SNPs may be measured by conventional genotyping approaches, e.g. selected from (i) hybridization methods utilizing sequence specific oligonucleotide probes (e.g., dynamic allele-specific hybridization, molecular beacons, or SNP microarrays), (ii) enzyme-based techniques such as restriction fragment length polymorphism (RFLP), polymerase chain reaction methods (e.g., tetra-primer ARMS-PCR with specific primers which can allow detection of the SNPs), flap endonuclease which allows detection of single nucleotide mismatches, primer extension techniques (e.g., hybridization of a probe to the bases immediately upstream of the SNP nucleotide followed by a 'mini-sequencing' reaction, in which DNA polymerase extends the hybridized primer by adding a base that is complementary to the SNP nucleotide), <NUM>'- nucleases using forward and reverse PCR primers that will amplify a region that includes the SNP, and oligonucleotide ligation assays, and (iii) post-amplification methods based on physical properties of DNA, such as single strand conformation polymorphism, temperature gradient gel electrophoresis, denaturing high performance liquid chromatography, high-resolution melting of the entire amplicon, use of DNA mismatch-binding proteins, and commercial systems such as SNPlex (Applied Biosystems). For example, the SNPs can be identified using a SNP microarray such as the Illumina Feline SNP60 array described in Example <NUM>. The kit to be used according to the present invention comprises a sequence specific oligonucleotide probe which recognizes one or more of the afore-mentioned three SNPs.

A cat can thus be identified as being at elevated risk of developing a disease or condition resulting from low hydration, e.g., a disease or condition selected from development of urinary stones (including bladder stones or kidney stones), feline idiopathic cystitis, and FLUTD, by a method comprising testing whether the cat exhibits one or more single nucleotide polymorphisms (SNPs) selected from chrB4. <NUM>, chrB4. <NUM> and chrB4. <NUM>, e.g., using any of the methods of SNP detection as set forth above. The invention provides the use of a diagnostic kit for identifying a cat as being at elevated risk of developing a disease or condition resulting from low hydration, e.g., a disease or condition selected from development of urinary stones (including bladder stones or kidney stones), feline idiopathic cystitis, and FLUTD, the kit comprising a sequence specific oligonucleotide probe which recognizes one or more single nucleotide polymorphisms (SNPs) selected from chrB4. <NUM>, chrB4. <NUM> and chrB4. <NUM>, and may further comprise instructions for such use.

Urine specific gravity values are determined for <NUM> cats that have been genotyped using the Illumina Feline SNP60 array (full description table <NUM>).

The distribution of animals per given urine specific gravity is plotted in <FIG>. Taking the deviation from the normal distribution a quantitative trait locus QTL analysis is performed. A Manhattan Plot is constructed, each single nucleotide polymorph ("SNP") genotyped is plotted against the significance of its correlation with the phenotype of urine specific gravity. Only one peak of SNPs is observed significantly above a false discovery cutoff of <NUM> (-<NUM>) indicating that this genetic locus is involved in determining the urine specific gravity. These SNPs are located in a locus on cat chromosome B4. The annotation and p values for the <NUM> most significant SNPS are given in Table <NUM>. The PTGES3 is the most likely candidate gene in this locus base on biological relevance as described above. This gene is flanked by the three SNPS, two upstream of the start of transcription and one downstream of the transcribed sequence. The positions of the SNPS are given relative to PTGES3 start site of transcription in Table <NUM> and the location of the PTGES3 gene with in the cat genome is describe in Table <NUM> including the build of the cat genome assembly used for this analysis.

The three SNP sequences and <NUM> basepairs flanking sequence are presented below, providing the SNP ID number, the specific SNP, and the sequence of the SNP plus a 200bp flanking sequence.

In Diet <NUM> the AA ratio to EPA is <NUM> to <NUM>, and in Diet <NUM> the ratio of AA to EPA is <NUM> to <NUM>. Diet <NUM> contains <NUM>% total fat, <NUM>% AA (<NUM>% total fat) and <NUM>% EPA (<NUM>% total fat). The test foods contained approximately <NUM>% protein. The high AA ratio fat concentration was <NUM>% while the low AA to EPA ratio was <NUM>% fat. The ratio of omega <NUM> fatty acids to omega-<NUM> fatty acids in Diet <NUM> is <NUM>. The animals are maintained on the two diets (<NUM> cats fed the high AA to EPA ratio and <NUM> cats fed the low AA to EPA ratio). Urine is collected and analyzed for urine specific gravity at day <NUM> and day <NUM>, data presented in Table <NUM> (g/ml):.

The group of cats on the high AA ratio diet (High) exhibits a significantly reduced urine specific gravity after <NUM> days. The group of cats on the low AA ratio diet (Low) exhibit no change in their urine specific gravity. In addition to urine specific gravity, blood osmolality is also measured as an indicator of level of hydration, data presented in Table <NUM> (mM/liter):.

As with urine specific gravity, there is a significant decrease in blood osmolality in cats fed the high AA diet but no change in the cats fed the low AA to EPA ratio (<FIG>). This indicates that not only does the high level of AA make the urine more dilute, but that the blood is also more dilute, indicating that the cats are taking in more water and that their overall water balance is increased. In other words, the cats are more hydrated.

In the control diet, the ratio of AA to EPA is <NUM> to <NUM>, in Diet A (the increased AA/EPA diet) the ratio of AA to EPA is ><NUM> to <NUM>, and in Diet B (the further increased AA/EPA diet) the ratio of AA to EPA is ><NUM> to <NUM>. The control diet contains <NUM>% total fat, <NUM>% AA (<NUM>% total fat) and <NUM>% EPA (<NUM>% total fat); Diet A contains <NUM>% total fat, <NUM>% AA (<NUM>% total fat) and <<NUM>% EPA (<<NUM>% total fat); and Diet B contained <NUM>% total fat, <NUM>% AA (<NUM>% total fat) and <<NUM>% EPA (<<NUM>% total fat). The ratio of omega-<NUM> fatty acids to omega-<NUM> fatty acids in Diet A is <NUM> and in Diet B is <NUM>. The animals are maintained on the three diets. Urine is collected and analyzed for urine specific gravity at day <NUM>, day <NUM> and day <NUM>. The results are as set forth in Table <NUM> (g/ml):.

The group of kittens on Diets A and B, the high AA ratio diet had a significantly reduced urine specific gravity after <NUM> days. The group of kittens on the control diet saw no change in their urine specific gravity.

Unlike the older cats, the kittens did not show significant differences in blood osmolality. See Table <NUM> (values in mM/liter):.

These data suggest that the ability to maintain normal osmolality values may be better in younger animals, regardless of diet, which may help explain why stones are more prevalent as the animals get older. This suggests that diet may have a greater influence on stone formation in older animals.

The formulations for Control diet, Diet A and Diet B are as follows:.

<NUM> with variables: AA, EPA
<NUM> variable: calcium oxalate RSS.

Dependent variable: Calcium oxalate RSS
<NUM> with variables: ratio
<NUM> variable: calcium oxalate RSS.

Claim 1:
Use of a diagnostic kit for identifying a cat as being at elevated risk of developing a disease or condition resulting from low hydration, the kit comprising a sequence specific oligonucleotide probe which recognizes one or more single nucleotide polymorphisms (SNPs) selected from chrB4.<NUM>, chrB4.<NUM>, and chrB4.<NUM>.