Is obesity a problem?
YES – obesity, defined as an excess of body weight of 20% or more, is the most common nutritional disease of domestic cats and dogs. Although the frequency varies from one country to the next, we know in some countries that up to 40% of adult dogs and cats are obese! With respect to the detrimental effects on health, obesity in the dog and cat is a known risk factor for both diabetes mellitus, lower urinary tract disease and arthritis. In humans, obesity causes an increase in morbidity and mortality at all ages and is associated with diabetes mellitus, certain types of cancer, impaired mobility and arthritis, high blood pressure, heart disease, and other illnesses. Recent studies suggest that heart disease might also occur in obese pets! More work is needed to evaluate this and to determine what other detrimental effects obesity has on cats.
Finally, obesity in cats is associated with hepatic lipidosis. This is a severe form of liver failure in cats. It typically occurs in cats which are obese and have then undergone a brief period of ‘stress’ which causes anorexia. The ‘stress’ may be as simple as a change of house or a change in diet. Hepatic lipidosis used to be an almost universally fatal disease in cats. Fortunately, with improved, aggressive and prolonged therapy about 80% of affected cats can be saved. However, it is because of the risk for this potentially fatal disease that treatment of feline obesity needs to be done cautiously and always under the care of a Veterinary surgeon.
What specifically causes obesity in pets and how should it be treated?
Many factors work together to cause obesity in pets. Some are probably genetic, while others are clearly related to diet and environment. It is important for the pet owner and Veterinary surgeon to keep all these factors in mind when treating the obese individual. Prevention is better than treatment but not always easy. Pets living indoors are more prone to obesity, perhaps because they eat more out of boredom, but also because they have less opportunity to stay trim through exercise. Remember, everybody should run and play, including cats!
Once a pet becomes obese, the challenge for owner and Vet is to promote weight loss safely and then to maintain the optimum weight. In the long run it is better to set realistic goals for weight reduction rather than attempting to force the cat down to a “normal” weight. Usually a 15-20% reduction in weight is a good target that can easily be achieved! Rapid weight loss should be avoided, since it puts the pets, especially cats, at risk for development of severe liver disease, discussed above. And weight that is lost slowly is more likely to stay lost! There are no drugs or magic pills which can be used safely or effectively. Commercial “low-calorie” diets are available from Veterinary surgeons and provide the basis for effective weight loss. However, they are more effective when combined with additional exercise. This also has the advantage of providing more time for interaction between the pet and the human, which we know provides enjoyment and is beneficial for the health of both. With some patience and extra care obese pets can be treated safely and effectively, with the ultimate goal of prolonging a healthy happy life!
In cats with access to outdoors it is vital to ensure that the cat does not have access to alternative food sources such as friendly neighbours!