The evidence is in regarding overweight dogs. And it's not pretty
Hi again. The previous post on exercise before growth plate closure in dogs generated quite a bit of interest. Some people were a bit confused about the recommendation to keep dogs thin. By thin, I mean lean. Perhaps more descriptive is dogs that are overweight have a shortened life span, their quality of life is adversely affected, and they are predisposed to systemic inflammation and other conditions including osteoarthritis and other orthopedic conditions, diabetes mellitus, immune-dysregulation, insulin resistance, pancreatitis, cardiovascular disease, and certain types of neoplasia, as well as other conditions.
Perhaps the most well-known study of orthopedic conditions is the life-time study of paired Labrador retriever littermates, which were placed in either an ad libitum fed group (ate pretty much what they wanted) or a group that received 25% less than their littermates. The incidence of hip dysplasia in the overweight group compared to the restricted-fed group was astounding, and the severity of arthritis was also greater in those eating almost as much as they wanted, not only in the hips, but also other joints. The dogs were followed for their lifetime, and the lean dogs lived nearly 2 years longer! This was confirmed in a more recent study. What is the logic behind letting dogs get overweight?
Keeping a dog at a healthy body condition score should not be in question. Dogs live longer, they eat less dog food (meaning more money in your pocket), they have less health problems (saving you a lot of money, especially in large and giant breeds of dogs), and they generally are more active and interact with the family more.
But, part of the problem may be that owners do not perceive that their dog is overweight (several studies have evaluated body condition scoring by owners versus veterinarians), and we need to do a better job as a veterinary profession in considering obesity a disease, and treating it like a disease with good follow-up and specific prescriptions for diet and exercise. Perhaps a simpler method of assessing body condition using girth measurements, as suggested by a recent study, may be better. Further, dog owners may not be accurate using various measuring cups to feed their dogs. Certainly owner education must be a part of all of this, and success occurs when the problem is properly assessed, relevant education is provided, and the dog owner is willing to learn, accept the advice, and make adequate changes.
Related to the previous post, a few people have made reference to growth and weight appropriate to the breed. But studies can be a bit confusing. One large study found that breed specific growth charts were generally quite good regarding appropriate growth. Another study found that recommended breed weight ranges are not a good predictor of an ideal body condition score. Just as in people, some of us gain weight while breathing air, while others have to eat a lot just to maintain their thin body weight. So many variables come into play, that it is almost impossible to follow a one-size-fits all mentality regarding how much to feed. We really need to rely on common sense, body condition scores, and professional guidance. But keeping puppies at a good body condition score seems to be important. One eye-opening study found that higher neonatal growth rate and body condition score at 7 months were predictive factors of obesity in adult dogs.
I had the opportunity to visit the Obesity Clinic at Liverpool University this year, and one of the main clinicians wrote a piece in Veterinary Record that I urge you to read. In that article, titled Dangerous Trends in Pet Obesity, he states “Obesity is a condition in which an excess body fat has developed to the point that health is adversely affected. Dogs that are overweight have a shortened life span, their quality of life is adversely affected, and they are predisposed to other conditions including osteoarthritis, diabetes mellitus and certain types of neoplasia. At a recent World Small Animal Veterinary Association One Health meeting, canine obesity was officially classified as a disease, which is consistent with its classification in people. The last study to report obesity prevalence in pet dogs in the UK was published in 2010. The study found 59 per cent of dogs were classified as overweight or obese. Between June 2016 and October 2017, dog owners attending seven different family pet shows in five UK locations (Berkshire, Cheshire, Hertfordshire, Kent and Manchester) consented to their dog having a body condition score assessment by a team of experienced veterinary nurses. Data from 1100 adult (≥24 months) and 516 juvenile (<24 months) dogs were available for analysis. In adult dogs, 715 (65 per cent) were overweight (body condition score of 6/9 to 9/9) and 99 (9 per cent) were obese (body condition score of 8/9 or 9/9). Most concerning was the prevalence of obesity in the juvenile dogs examined, where 190 (37 per cent) and 16 (3 per cent) were classified as overweight and obese, respectively. Further, the prevalence increased steadily during the growth phase, from 21 per cent (21/100) in dogs younger than six months of age to 52 per cent (16/31) in dogs 18 to 24 months of age.”( Alexander J. German, Georgiana R. T. Woods, Shelley L. Holden, Louise Brennan, Caroline Burke, VET RECORD, 6 January 2018, p 25)
An excellent resource regarding overweight dogs and related issues may be found at the World Small Animal Veterinary Association website, https://www.wsava.org/Global-Guidelines/Global-Nutrition-Guidelines. There is something here for everyone, both veterinarians and dog owners, regarding body condition scoring and dietary recommendations.
I also was quite interested in the different perceptions regarding exercise for immature dogs on one of the social media sites. People made reference to the 5 minutes per month guideline for exercise of puppies. I was unable to find any literature regarding this specific recommendation, and many people making comments were uncertain about exactly what this refers to, e.g. leash walks, play with other dogs or people, free exercise, a combination, etc. The exercise science has been referenced in the previous post. I also found it interesting that people involved with performance exercise, sch as sled dog racing, were training their dogs at quite a high level, with apparently no issues. This may not be the case for all breeds, however.
I think the application of science where it is known is appropriate, and where there are no studies, making inferences from what data is available, along with common sense and experience are appropriate. I do feel that when the evidence is pretty conclusive, however, that we need to move forward and apply the information to the betterment of our dogs, and not do things just because that is what we have always believed.
Leptin and Immunological Profile in Obesity and Its Associated Diseases in Dogs. Cortese, Laura; Terrazzano, Giuseppe; Pelagalli, Alessandra. Int J Molec Sci Volume: 20(10), 2019 Article Number: 2392
Dangerous trends in pet obesity. German, AJ; Woods, GRT; Holden, SL; Brennan, L; Burke, C. Vet Record 182(1):25-25, 2018 DOI: 10.1136/vr.k2
The effects of lifetime food restriction on the development of osteoarthritis in the canine shoulder. Runge, JJ; Biery, DN; Lawler, DF; Gregor, TP; Evans, RH; Kealy, RD; Szabo, SD; Smith, GK. Vet Surg 37(1):102-107, 2008
Effects of diet restriction on life span and age-related changes in dogs. Kealy, RD; Lawler, DF; Ballam, JM; et al. J Amer Vet Med Assoc 220(9):1315-1320, 2002
Evaluation of the effect of limited food consumption on radiographic evidence of osteoarthritis in dogs. Kealy, RD; Lawler, DF; Ballam, JM; et al. J Amer Vet Med Assoc 217(11):1678-1680, 2000
Body weight at 10 years of age and change in body composition between 8 and 10 years of age were related to survival in a longitudinal study of 39 Labrador retriever dogs. Penell, JC; Morgan, DM ; Watson, P; Carmichael, S; Adams, VJ. Acta Vet Scand 61(1) Article Number: 42, 2019 DOI: 10.1186/s13028-019-0477-x
Association between life span and body condition in neutered client-owned dogs. Salt C; Morris PJ.; Wilson Dk; et al. J Vet Int Med 33(1):89-99, 2019
Scope of the Problem and Perception by Owners and Veterinarians. Larsen, Jennifer A.; Villaverde, Cecilia. Vet Clin N Amer-Sm Anim Prac 46(5):761- ,2016
Canine obesity: is there a difference between veterinarian and owner perception? White, G. A.; Hobson-West, P.; Cobb, K.; et al. J Sm Anim Prac 52(12):622-626, 2011
Dog owner's accuracy measuring different volumes of dry dog food using three different measuring devices. Coe JB; Rankovic A; Edwards T.; et al. Vet Rec 185(19) NOV 16 2019
Improving the Welfare of Companion Dogs-Is Owner Education the Solution? Philpotts, I; Dillon, J; Rooney, N. Animals 9(9) Article Number: 662, 2019 DOI: 10.3390/ani9090662