About half of U.S. dogs and cats are overweight, and a third of dogs visiting the vet in the last decade were clinically obese. As is the case with humans, obesity affects both the quantity and quality of life pets enjoy.
Pet obesity is a serious health threat. There are several common disorders and diseases directly attributable to obesity, including:
- Decreased life span
- Dystocia (difficult birth)
- Hepatic lipidosis (cats)
- Cruciate ligament tears/ruptures
- Exercise intolerance
- Mammary neoplasia (tumor)
- Laryngeal paralysis
- Glucose intolerance
- Idiopathic cystitis
- Transitional cell carcinoma
- Tracheal collapse
- Intervertebral disk disorder
- Urethral sphincter mechanism incompetence
There are a number of contributors to obesity. For example, it is suspected but not proven that certain breeds are predisposed to obesity. However, a clear link has been established between neutered dogs and overweight, and the same is presumed to be true for cats.
In fact, a study with Beagles showed after neutering the dogs needed a 30 percent decrease in calories or an equivalent increase in activity in order to maintain a healthy weight.
The hormone leptin is also a major factor in obesity. Leptin acts on reproductive and immune functions and also on insulin sensitivity.
Leptin binds to receptors in the brain that are directly related to appetite suppression. Overweight people and pets have high circulating leptin levels, so it is not a lack of the hormone that is the problem, but the inability of leptin to act on the hypothalamus in overweight animals. Animals are becoming as leptin-resistant as people.
Another hormone important in obesity is adiponectin. Adiponectin enhances insulin sensitivity and increases glucose uptake. Low levels of this hormone are associated with type 2 diabetes, insulin resistance and high blood pressure in humans. While the same connection has not yet been established in companion animals, it is a fact that obese dogs and cats have decreased levels of adiponectin.
According to Clinician’s Brief:
Management of weight issues in pets is complicated by the human–animal bond. The increase in obesity of pets is increasing as human obesity increases in the population. Most veterinarians would agree that it can be very awkward to discuss a pet’s weight issue if the owner has a weight issue.