Obesity affects pets adversely in many ways. Overweight pets tend to play and exercise less and don't live as long as healthy pets do. In fact, the list of harmful effects of obesity on pets is a long one.
Overweight pets have a lower resistance to infection and tend to be less able to fight off infectious diseases. Obese pets also have an increased incidence of arthritis (degenerative joint disease), spinal disc problems, and torn knee ligaments than normal pets. Overweight pets also have more problems moving about than their thinner counterparts.
Obesity leads to impaired endurance during exercise, increased fatigue, and high blood pressure. The increased workload on the heart contributes to an increase in heart disease in overweight pets, leading eventually to congestive heart failure.
Diagnosis is more difficult in obese pets, because it is more difficult to auscultate or palpate a fat pet, or to get proper samples. Fat pets are at a greater risk during anesthesia and surgery since they have reduced lung function, decreased liver and kidney function, greater risk of wound infection, and require more anesthetic than normal pets.
The incidence of skin problems is 40 per cent higher in overweight dogs than dogs at optimum body weight. Because of the insulating properties of fat, overweight pets are less able to endure hot weather, and many become more irritable.
Other problems associated with obesity include:
- Diabetes mellitus - Pets that are obese have an increased risk and severity of diabetes mellitus.
- Gastrointestinal problems - Overweight pets have increased constipation, flatulence, and stomach ulcers.
- Increased cancer rate - There is also a higher cancer rate in overweight pets. For example, the incidence of cancer is 50% higher in overweight dogs than in healthy dogs.
- Reduced liver function - Due to the accumulation of fat in the liver, the liver's ability to function can be compromised in obese pets.
- High blood pressure - High blood pressure (hypertension) worsens with obesity, and hypertension increases the risk of kidney, heart, and vascular diseases.
- Impaired hormone release - The release of growth hormone is impaired in overweight pets, as is their reproductive efficiency.
All these effects contribute to a reduced lifespan and affect the quality of a pet's life. Pets that are healthy and physically fit tend to live longer, are happier, and enjoy life more.