Latest developments in breed diets for companion animals

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1 Vet Times The website for the veterinary profession Latest developments in breed diets for companion animals Author : Lisa Weeth Categories : Companion animal, Vets Date : November 28, 2016 The domestication of dogs began more than 30,000 years ago 1, but many of our modern breeds have more recent origins within the past 200 years. The cat on the right has been fed a diet formulated to be complete and balanced for adult cats according to a computer analysis, but the levels of phenylalanine and tyrosine were inadequate to maintain the black hair phenotype. Archaeological and genetic evidence indicates cats began living with humans approximately 12,000 years ago presumably after the shift in food production from a hunter-gatherer lifestyle to that of farmed (and stored) agricultural products 2. However, most modern cat breeds, as we know them today, originated only within the past 50 years 3. The popularity of selectively bred dogs versus randomly bred cats is reflected in the pet population statistics for the UK. While crossbreed and domestic top the list of dog and cat breeds, respectively, the next most popular breeds for dogs are Labrador retriever, Staffordshire bull terrier, Jack Russell terrier and Yorkshire terrier, while the next four most popular cat breeds are no breed identified, British shorthair, crossbreed and Persian 4. While breed-specific diet marketing is often just that marketing selective pressures imposed by human aesthetics for the past 200 years have caused unintended consequences on the 1 / 6

2 requirements for certain nutrients, as well as changes in overall intestinal physiology 5 that may be, optimally, addressed through feeding a more targeted diet. Breed-specific nutrient requirements Nutrients (vitamins, minerals, proteins, fats and carbohydrates) are required either for normal body functions or to serve as a precursor for additional compounds, proteins or hormones produced in the body. All dogs, irrespective of phenotypic variation, have the same essential nutrient requirements. However, in the past few decades, differences in nutrient metabolism and physiology between representative breed lines have been identified, and can affect skeletal development, skin and coat health and general gastrointestinal physiology. The potential for feline breed-specific nutrient requirements has not been given the same level of attention, though extreme facial morphology of certain breeds, as seen in Persians, has been found to affect prehension and acceptance of certain diets 6, and differences in coat length and colour influence the requirement of certain key essential nutrients. Skeletal development in growing puppies Large and giant breed puppies are especially sensitive to dietary imbalances during the first year of growth. Excessive calcium intake can lead to developmental orthopaedic diseases and long bone deformities 7,8, while too rapid a skeletal growth rate from excess calcium and energy intake can lead to painful osteochondrosis lesions in the joint or inflammation of the tissue surrounding the growing bones (panosteitis) 9. These pathologic changes with excess calcium intake have not been seen in developing kittens. For the rest of the essential minerals (phosphorus, magnesium, manganese, sodium, potassium, chloride, molybdenum, selenium, zinc, copper, iron and iodine) and vitamins (thiamine, riboflavin, niacin, pyridoxine, cobalamin, folic acid, choline, and vitamins A, D, E and K) a relative consistency in nutrient requirements exists for both growing animals and healthy adults. Skin and coat health 2 / 6

3 The same cat as above right, six months after changing to a diet with higher phenylalanine and tyrosine content. The essential fatty acids linoleic acid (LA; and omega-6 long-chain fatty acid) and alpha-linolenic acid (ALA; and omega-3 long-chain fatty acid) are required in the diet to maintain a supple skin and hair coat. Long-coated breeds have a higher requirement for these two nutrients to maintain coat quality and lustre, compared to their short-coated counterparts likely due to varying levels of ceramide production 5,10. Arctic dog breeds are also at risk of zinc-responsive dermatitis due to decreased intestinal absorption of zinc 11, whereas black coat variants of any breed (cat or dog) require higher intakes of phenylalanine (an essential amino acid) and its associated metabolic product tyrosine (a nonessential amino acid) to produce adequate levels of melanin to maintain a solid black hair colour 12,13. Taurine metabolism Taurine is incorporated into the retina and cardiac muscle, and is required for normal ocular and cardiac health. All cats, irrespective of breed, are unable to synthesise sufficient levels of taurine from the sulphur amino acid precursors, methionine and cysteine, and have an absolute requirement for pre-formed taurine in the diet. Conversely, dogs as a species are able to synthesise adequate levels of taurine from dietary precursors, with notable exceptions under certain circumstances. After a cluster of large breed dogs developed taurine-deficient cardiomyopathy while eating what appeared to be complete and balanced commercial adult dog 3 / 6

4 foods 14, investigators found certain breeds appeared to have a lower overall synthesis of taurine 15-17, and taurine deficiency could develop if low total dietary protein was coupled with a higher fibre intake, causing increased taurocholic acid loss from the gastrointestinal tract 18. Digestive physiology When comparing general disease prevalence among populations of dogs, larger breeds appear to suffer from more gastrointestinal disorders than small and medium breeds 5. This may be related to the fact total gastrointestinal transit time and faecal quality have been found to vary with body size across all breeds 19,20 with larger breeds having higher faecal water content and faster transit times overall. More recent work looking at the effect of specific macronutrient component of the diet on faecal quality has found breed-specific differences in the fermentation characteristic of undigested protein, resistance starch (undigested dietary carbohydrates) and dietary fibre 21,22. These findings suggest the diets necessary to maintain optimal intestinal health and stool quality in large breeds, such as German shepherd dogs and Labrador retrievers, are different than those needed by small to medium-sized breeds. Energy requirements All commercial pet food packages are required to list feeding guidelines based on a given bodyweight of dog or cat. These amounts are reported as the daily energy requirements and are calculated for a healthy animal using the formula 1.6 (70bw[kg] 0.75) for dogs and 1.2 (70bw[kg] 0.75 ) for cats 23. The problem with calculated requirements is individual animals will vary by up to plus or minus 50 per cent of these values, and while less variation exists among cat breeds, there can be dramatic differences in dog breeds, with large and giant breeds often having lower daily energy requirements on a metabolic bodyweight basis during growth and maintenance compared to small to medium-sized breeds 24,25. Implications on diet selection The understanding of nutrient absorption, interaction and optimal intakes for dogs and cats has grown dramatically in the past 100 years. Early nutritional research was focused on identifying minimum requirements for growth and reproduction, and preventing signs of deficiencies, while more current research seeks to optimise long-term health and wellness in adults, as well as to use nutrient modifications to manage disease states. With advances in manufacturing technology, growth in the field of nutrigenomics and identifications of breed-specific nutritional requirements, a wide range of commercial diets are available that can optimise health and wellness for companion dogs and cats, and breed-specific diets are among 4 / 6

5 them. References 1. Axelsson E et al (2013). The genomic signature of dog domestication reveals adaptation to a starch-rich diet, Nature 495(7,441): Driscoll CA et al (2009). The Taming of the cat. Genetic and archaeological findings hint that wildcats became housecats earlier and in a different place than previously thought, Sci Am 300(6): Lipinski MJ et al (2008). The ascent of cat breeds: genetic evaluations of breeds and worldwide random bred populations, Genomics 91(1): Demographic information on UK pets, RVC, 5. Asher L et al (2009). Inherited defects in pedigree dogs, part 1: disorders related to breed standards, Vet J 182(3): Figge K (2011). Kibble Shape and its Effect on Feline Palatability, Pet Food Forum ( 7. Hazewinkel HA et al (1991). Calcium metabolism in Great Dane dogs fed diets with various calcium and phosphorus levels, J Nutr Suppl 121(S11): Laflamme D (2001). Effect of breed size on calcium requirements for puppies, Compend Contin Educ Pract Vet 23(9A): Corbee RJ et al (2012). Composition and use of puppy milk replacers in German shepherd puppies in the Netherlands, J Anim Physiol Anim Nutr (Berl) 96(3): Strain GM (1996). Aetiology, prevalence and diagnosis of deafness in dogs and cats, Br Vet J 152(1): Brown RG et al (1978). Alaskan Malamute chondrodysplasia. V. Decreased gut zinc absorption, Growth 42(1): Biourge V and Sergheraert R (2002). Hair pigmentation can be affected by diet in dogs, Proc Comp Nutr Soc 4: Yu SC et al (2001). Effect of low levels of dietary tyrosine on the hair colour of cats, J Small Anim Pract 42(4): Fascetti AJ et al (2003). Taurine deficiency in dogs with dilated cardiomyopathy: 12 cases ( ), JAVMA 223(8): 1,137-1, Belanger MC et al (2005). Taurine-deficient dilated cardiomyopathy in a family of golden retrievers, JAAHA 41(5): Kittleson MD et al (1997). Results of the multicenter spaniel trial (MUST): taurine- and carnitine-responsive dilated cardiomyopathy in American cocker spaniels with decreased plasma taurine concentration, J Vet Intern Med 11(4): Delaney SJ et al (2003). Plasma and whole blood taurine in normal dogs of varying size fed commercially prepared food, J Anim Physiol Anim Nutr (Berl) 87(5-6): Ko KS and Fascetti AJ (2016). Dietary beet pulp decreases taurine status in dogs fed low protein diet, J Anim Sci Technol 58: / 6

6 Powered by TCPDF ( 19. Hernot DC et al (2005). Relationship between total transit time and faecal quality in adult dogs differing in body size, J Anim Physiol Anim Nutr (Berl) 89(3-6): Weber MP, Biourge VC and Nguyen PG (2016). Digestive sensitivity varies according to size of dogs: a review, J Anim Physiol Anim Nutr (Berl), [Epub ahead of print]. 21. Nery J et al (2010). Influence of dietary protein content and source on fecal quality, electrolyte concentrations, and osmolarity, and digestibility in dogs differing in body size, J Anim Sci 88(1): National Research Council (2006). Nutrient requirements of dogs and cats, National Academic Press, Washington, DC: Goudez R et al (2011). Influence of different levels and sources of resistant starch on faecal quality of dogs of various body sizes, Br J Nutr Suppl 106(S1): Dobenecker B et al (2013). Energy requirements of puppies of two different breeds for ideal growth from weaning to 28 weeks of age, J Anim Physiol Anim Nutr (Berl) 97(1): Finke MD (1991). Evaluation of the energy requirements of adult kennel dogs, J Nutr Suppl 121(S11): / 6