Obesity in pets occurs when excessive adipose tissue accumulates in the body,[1] and is generally defined as occurring when an animal's body weight is at least 20% greater than its optimal body weight.[2] Obesity is associated with metabolic and hormonal changes, and can predispose pets to illnesses like orthopedic disease, diabetes, and cancer.[1][3][4]

A cat with obesity

Diagnosis

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For dogs and cats, a 9 point body condition score (BCS) system is used to identify whether they are above their ideal weight status.[5] Scores 1-3 indicate 'too thin', 4 and 5 are 'ideal', 6 is 'above ideal', 7 is 'overweight' and 8 and 9 are 'obese'. There are numerous versions of the BCS chart available for use including 5-point and 7-point versions, however, the 9-point chart is the only version where the scores correlate with true body fat percentage measured using dual-energy X-ray absorptiometry (DEXA) scans.[6]

Assigning a body condition score to a pet involves visual assessment and palpation of the animal to assess fat padding. An ideally conditioned dog should have a tapered waist when viewed from above and a clear abdominal tuck when viewed from the side. Ribs should not be visible, but ribs should be easily palpated with only a very thin layer of fat cover.[5] Ideally conditioned cats will have a waist that can be observed behind their ribs, a slight fat pad over their ribs, and a minimal abdominal fat pad with no abdominal tuck.[7]

 
Canine body condition score (BCS) system

These BCS methods are the most commonly used ways of diagnosing obesity in practice. Whilst they are not as accurate as performing DEXA scans that measure true body fat percentage, Body Condition Scoring is quick, non-invasive and requires no specialist equipment, just the scoring charts and a clinician. Similar systems exist for livestock.[8] For horses there is the Henneke horse body condition scoring system.

Using weight alone is not a reliable tool for diagnosing obesity as individuals within a species and breed can vary significantly in their size. Weighing is still useful for monitoring changes and a gain in weight may be an indication of excess weight and should prompt assessing BCS. For dogs under a year there are Puppy Growth Charts [9] where weights can be monitored in relation to an average growth curve, this again helps to monitor whether weight is increasing more than expected and deviating from the average growth curve should prompt assessing BCS.

Causes

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Obese labrador retrievers in India

Weight gain will occur when an animal is in a positive energy balance, meaning energy provided as calories in the diet exceed calories expended.[10] Evidence suggests that middle-aged cats and dogs, especially those between the ages of 5 and 10, may be at an increased risk of obesity.[11] This is supported by studies showing that as cats age from 2 years to approximately 11.5 years of age their energy requirements decrease.[12] Weight gain will occur if calories from the diet do not decrease with the animal's energy requirements.[12]

Obesity in pets is usually due to excessive food intake or lack of physical exercise.[13] Owners may view food as a way to reward and treat their pets, which contributes to overfeeding.[14] Pets confined to a house or small yard which are not regularly exercised are more prone to obesity.[14]

The risk of obesity in dogs (but not in cats) can be related to whether or not their owners are obese. The main factor seems to be obese owners not walking their dogs as much.[15]

In cats, neutering increases the risk of obesity, partly because the alteration in sex hormones after neutering lowers the basal metabolic rate, and partly because neutered cats have a reduced inclination to roam compared to non-neutered cats.[16]

Management

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Weight management has two steps: weight loss and weight maintenance. In the weight loss phase, energy intake from food must be less than the energy expended each day.[17] Achieving weight loss in cats and dogs is challenging, and failure to lose weight is common.[17] If the animals themselves cannot control their own calorie intake, it is recommended that pet owners control the food amount given. Guidelines exist on energy allowances for animals of a given body weight.[18]

Medical treatments have been developed to assist dogs in losing weight. Dirlotapide (brand name Slentrol) and mitratapide (brand name Yarvitan) were authorized for use in the EU by the European Medicines Agency for helping weight loss in dogs, by reducing appetite and food intake, but both of these drugs have been withdrawn from the market in the EU.[17] The US Food and Drug Administration approved dirlotapide in 2007.[19] Up to 20% of dogs treated with either dirlotapide or mitratapide experience vomiting and diarrhea; less commonly, loss of appetite may occur.[20] When these drugs are stopped, the dog's appetite returns to previous levels.[20] If other weight-loss strategies are not employed, the dog will again gain weight.[20]

Outcomes

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Compared to non-obese animals, obese dogs and cats have a higher incidence of osteoarthritis (joint disease) and diabetes mellitus, which also occur earlier in the life of the animal.[1] Obese animals are also at increased risk of complications following anesthesia or surgery.[1]

Obese dogs are more likely to develop urinary incontinence, may have difficulty breathing, and overall have a poorer quality of life compared to non-obese dogs,[17] as well as having a lower life expectancy.[1] Obese cats have an increased risk of diseases affecting the mouth and urinary tract.[17] Obese cats which have difficulty grooming themselves are predisposed to dry, flaky skin and feline acne.[21]

Epidemiology

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In the United States, the prevalence of obese or overweight adult dogs is 23–53%, of which about 5% are obese;[22][23] the incidence in adult cats is 55%,[23] of which about 8% are obese.[22]

In Australia, obesity is the most common nutritional disease of pets;[24] the prevalence of obesity in dogs in Australia is approximately 40%.[14]

Society and culture

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Pet owners in the UK have been prosecuted for cruelty to animals due to their pets being dangerously obese.[25]

In the US, National Pet Obesity Awareness Day, is on the 14th of October.[26][27]

See also

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References

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  1. ^ a b c d e Zoran, Debra L. (March 2010). "Obesity in dogs and cats: A metabolic and endocrine disorder". Veterinary Clinics of North America: Small Animal Practice. 40 (2): 221–239. doi:10.1016/j.cvsm.2009.10.009. PMID 20219485.
  2. ^ Linder, D; Mueller, M (July 2014). "Pet obesity management: beyond nutrition". The Veterinary Clinics of North America. Small Animal Practice. 44 (4): 789–806, vii. doi:10.1016/j.cvsm.2014.03.004. PMID 24951347.
  3. ^ Chandler, M.; Cunningham, S.; Lund, E.M.; Khanna, C.; Naramore, R.; Patel, A.; Day, M.J. (May 2017). "Obesity and Associated Comorbidities in People and Companion Animals: A One Health Perspective". Journal of Comparative Pathology. 156 (4): 296–309. doi:10.1016/j.jcpa.2017.03.006. hdl:1983/ccd76afc-d4c7-489d-8b1f-9f32e081be45. PMID 28460795. S2CID 4113376.
  4. ^ Howe, Lisa (May 2015). "Current perspectives on the optimal age to spay/castrate dogs and cats". Veterinary Medicine: Research and Reports. 6: 171–180. doi:10.2147/VMRR.S53264. ISSN 2230-2034. PMC 6070019. PMID 30101104.
  5. ^ a b Laflamme, D.R (1997). "Development and validation of a body condition score system for dogs". Canine Practice. 22 (4): 10–15.
  6. ^ Mawby, D.I; Bartges, J.W; d'Avignon, A; Laflamme, D.P; Moyers, T.D; Cottrell, T (2004). "Comparison of various methods for estimating body fat in dogs". Journal of the American Animal Hospital Association. 40 (2): 109–114. doi:10.5326/0400109. PMID 15007045.
  7. ^ "Feline Body Condition Score" (PDF). The World Small Animal Veterinary Association. Retrieved February 8, 2023.
  8. ^ "Body Condition Scoring | Animal Health and Welfare". Government of Saskatchewan.
  9. ^ Waltham. "Waltham Puppy Growth Charts". www.waltham.com.
  10. ^ Case, Linda; Daristotle, Leighann; Hayek, Michael; Foess-Raasch, Melody (2011). Canine and Feline Nutrition: A Resource for Companion Animal Professionals (Third ed.). Elsevier. p. 59.
  11. ^ Tilley, Larry; Smith, Francis (September 29, 2015). Blackwell's Five-Minute Veterinary Consult: Canine and Feline (Sixth ed.). John Wiley & Sons. p. 960.
  12. ^ a b Laflamme, Dorothy (2005). "Nutrition for Aging Cats and Dogs and the importance of Body Condition". Vet Clin Small Anim. 35 (3): 713–742. doi:10.1016/j.cvsm.2004.12.011. PMID 15833567.
  13. ^ German, AJ (July 2006). "The growing problem of obesity in dogs and cats". The Journal of Nutrition. 136 (7 Suppl): 1940S–1946S. doi:10.1093/jn/136.7.1940S. PMID 16772464. 
  14. ^ a b c Larsen, JA; Villaverde, C (September 2016). "Scope of the problem and perception by owners and veterinarians". The Veterinary Clinics of North America. Small Animal Practice. 46 (5): 761–72. doi:10.1016/j.cvsm.2016.04.001. PMID 27264053.
  15. ^ Nijland ML, Stam F, Seidell JC (June 2009). "Overweight in dogs, but not in cats, is related to overweight in their owners". Public Health Nutr. 13 (1): 102–106. doi:10.1017/S136898000999022X. PMID 19545467. 
  16. ^ Rand, J, ed. (2007). "Obesity". Problem-based feline medicine (Repr. ed.). Edinburgh: Saunders Elsevier. pp. 452–455. ISBN 9780702024887.
  17. ^ a b c d e German, AJ (20 October 2016). "Weight management in obese pets: the tailoring concept and how it can improve results". Acta Veterinaria Scandinavica. 58 (Suppl 1): 57. doi:10.1186/s13028-016-0238-z. PMC 5073926. PMID 27766974.
  18. ^ "Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs". FEDIAF.
  19. ^ Klonoff, DC (2007). "Dirlotapide, a U.S. Food and Drug Administration-approved first-in-class obesity drug for dogs-will humans be next?". J Diabetes Sci Technol. 1 (3): 314–6. doi:10.1177/193229680700100301. PMC 2769592. PMID 19885086.
  20. ^ a b c Chandler, MJ (2012). "Pharmaceutical therapy and weight loss". In Washabau, WJ; Day, MJ (eds.). Canine and Feline Gastroenterology. London: Elsevier Health Sciences. p. 395. ISBN 9781437703023.
  21. ^ Lappin, MR, ed. (2001). "Obesity and polyphagia". Feline internal medicine secrets. Philadelphia: Hanley & Belfus. pp. 311–315. ISBN 9781560534617.
  22. ^ a b Lund Elizabeth M. (2006). "Prevalence and Risk Factors for Obesity in Adult Dogs from Private US Veterinary Practices" (PDF). Intern J Appl Res Vet Med. 4 (2): 177–86.
  23. ^ a b de Godoy, MR; Swanson, KS (June 2013). "Companion Animals Symposium: nutrigenomics: using gene expression and molecular biology data to understand pet obesity". Journal of Animal Science. 91 (6): 2949–64. doi:10.2527/jas.2012-5860. PMID 23296821.
  24. ^ McGreevy PD, Thomson PC, Pride C, Fawcett A, Grassi T, Jones B (May 2005). "Prevalence of obesity in dogs examined by Australian veterinary practices and the risk factors involved". Veterinary Record. 156 (22): 695–702. doi:10.1136/vr.156.22.695. PMID 15923551. S2CID 36725298.
  25. ^ Boden, E; Andrews, A (2017). "Obesity". Black's Student Veterinary Dictionary (22nd ed.). Bloomsbury Publishing. p. 621. ISBN 9781472932037.
  26. ^ Shaw, Lorrie. "Local vet weighs in on chubby pets on National Pet Obesity Awareness Day". Annarbor.com. Retrieved 2012-10-11.
  27. ^ Chion, Linda (2011-06-29). "Is Your Dog or Cat Too Fat? Advice on Pet Obesity Awareness Day - Brandon, FL Patch". Brandon.patch.com. Retrieved 2012-10-11.