The estimated prevalence of obesity in dogs is between 20-40%, and this leads to significant medical issues such as cardiovascular disease, pancreatitis, insulin resistance and changes in glucose metabolism, as well as musculoskeletal issues such as early development of osteoarthritis, muscle atrophy, ligament strain, cartilage degeneration, deconditioning and reduced range of movement (Mlacnik et al, 2006 and Manens et al, 2014).
When treating an overweight dog we have to consider a conditioning programme very carefully, so as not to overload the cardiovascular or musculoskeletal systems and avoid further injury or illness.
Research shows that combining a calorie restricted diet to 60% of what the dog should have for its weight and intensive physical therapy is more efficient for weight loss than just diet alone (Mlacnik et al, 2006). Nothing new there then, from what we know in humans, but my question is: what should we be monitoring and what considerations do we need to take when creating an exercise programme for obese dogs?
Looking at the evidence, I found that like in humans with obesity, lean body mass is often lost when there is a reduction in adipose tissue in dogs. In calorie-restricted diets without exercise, a downregulation of micro-RNAs has been observed and they play an important role in muscle hypertrophy. Hence without exercise involvement, lean body mass is lost. Therefore a positive impact on energy metabolism is observed when combining exercise and calorie controlled programmes, it helps to maintain healthy musculoskeletal tissues and ensure desired improvements occur (Herrera Uribe et al, 2016).
It is also vital to consider the effects of obesity on the cardiovascular system of a dog. There is limited research on body condition, level of exercise and heart rate but a paper by Kuruvilla and Frankel, (2003) found that obese dogs had a significantly greater resting heart rate than lean dogs and a higher heart rate during recovery (as a percentage of heart rate during exercise). Resting heart rate is thought to increase in obese dogs as a compensatory measure for an increase in energy requirement because of an increase in body mass and a reduction in ventilatory function, such as reduced tidal volumes with a rapid and shallow breathing pattern (Manens et al, 2014).
This is significant to consider in designing exercise programmes as overweight dogs will reach heart rate maximum very quickly and will not be able to sustain it for prolonged periods, so it is important to measure heart rate and consider small bursts of exercise with longer recovery periods.
Another vital component to designing an exercise programme for obese dogs is to have an outcome measure such as the six minute walk test (6MWT), where heart rate, respiration rate and oxygen saturation are all measured if possible. The 6MWT has been found to be an efficient outcome measure in demonstrating that reducing body weight improves cardiopulmonary function in dogs (Manens et al, 2014).
With the increasing use of technology today, dog pedometers can be a nice way to monitor the activity your canine is doing- you can therefore monitor activity loading and what is optimal for the condition you are managing with advice from your physio. We like Poochplay app and tracker as it is easy to use and not too expensive.
References:
Herrera Uribe, J., Vitger, A., Ritz, C., Fredholm, M., Bjørnvad, C. and Cirera, S. (2016) ‘Physical training and weight loss in dogs lead to transcriptional changes in genes involved in the glucose-transport pathway in muscle and adipose tissues,’ The Veterinary Journal, 208, pp.22-27.Kuruvilla, A. and Frankel, T.L. (2003) ‘Heart rate of pet dogs: effects of overweight and exercise,’ Asia Pacific Journal of Clinical Nutrition, 12, pp. 24.Manens, J., Ricci, R., Damoiseaux, C., Gault, S., Contiero, B., Diez, M. and Clercx, C. (2014) ‘Effect of Body Weight Loss on Cardiopulmonary Function Assessed by 6-Minute Walk Test and Arterial Blood Gas Analysis in Obese Dogs,’ Journal of Veterinary Internal Medicine, 28(2), pp.371-378.Mlacnik, E., Bockstahler, B., Müller, M., Tetrick, M., Nap, R. and Zentek, J. (2006) ‘Effects of caloric restriction and a moderate or intense physiotherapy program for treatment of lameness in overweight dogs with osteoarthritis,’ Journal of the American Veterinary Medical Association, 229(11), pp.1756-1760.