The following health problems are linked to cat obesity. The information comes from a study by Hand et al 2000 as published in The Welfare of Cats and excellent reference book on domestic and feral cats edited by Irene Rochlitz and authored by a range of experts.
- Feline lower urinary tract disease
- Fatty infiltration of the liver
- Poor responses to infectious diseases
- Insulin resistance and the possible development of feline diabetes
- Respiratory difficulties
- Decreased cardiac reserve (see below)
- With respect to surgery obese cats are under a greater risk due to: slower wound healing, it is more difficult to perform the surgery, increased risk of a negative outcome from anaesthesia and fat necrosis.
Most cases of cat obesity are due to eating too much (increased calorific intake) alone or in conjunction with a reduced requirement for food because the cat is less active.
In cats obesity is defined as a cat being more than 15% above ideal weight. In Western Europe and the United States obesit is the most common nutritional problem in pets and it affects between 10% and 20% of companion cats. Sometimes, rarely, it is caused by metabolic or endocrine disease or enlargement of abdominal structures.
“Decreased cardiac reserve”, means a reduction in the difference between the rate at which the heart pumps blood at its maximum capacity compared to the rate at which it pumps blood at any given time. It appears to represent the difference between the amount the heart pumps normally to the amount the heart can pump at a maximum. Normally this is a factor of 4-5 times for a healthy person. Clearly with respect to being obese, this extra capacity of the heart is reduced because of, I assume, internal fatty tissues on the organs.
With respect to changing diet, some cats show strong food preferences. Changing the diet can be difficult and may take a gradual change over two weeks or more. Cat owner should not force their cat to eat a new food by not providing any alternatives. This is forcing your cat to try need new foods which I am told is rarely successful. It can result in hepatic lipidosis, which is a serious and potentially fatal liver disease.
Some more on feline obesity