Diabetes mellitus is also referred to as ‘sugar’ diabetes and is one of the most common endocrine disorders of cats. It is due to insulin deficiency. Insulin regulates the flow of glucose from the blood to the cells to be used as energy. When levels of insulin are too low, cells need to find other energy sources and deplete fat and protein stores in the body, while high levels of glucose remain in the bloodstream.
We can differentiate between two types of diabetes mellitus: IDDM (insulin-dependent diabetes mellitus), a disease where a cat’s pancreas does not produce any or enough insulin and NDDM (non-insulin-dependent diabetes mellitus), when the cells’ ability to respond to insulin is impaired. IDDM is rare in humans and even rarer in cats.
Research has identified several risk factors for development of DM: body weight, age, gender and neutering. Obesity plays a significant role: ‘The etiologic fraction for high body weight was 3.8%, suggesting that an estimated 3.8% of cases of diabetes mellitus was attributable to this factor alone’, (Panciera et al, 1990). Age was the most important risk factor : ‘Over 50% of diabetic cats were greater than 10 years old, and the etiologic fraction for age greater than 7 years alone was 73.5%’, (Panciera et al, 1990). Gender also has an impact: male cats are worse affected than females.
Breed does not seem to be significant although it is reported that, in some countries (e.g. Australia), some lines of Burmese cats are particularly affected by DM.
DM can also be a side effect of other diseases, like chronic pancreatitis, hyperthyroidism, Cushing’s syndrome and acromegaly.
DM can be brought on by long term use of certain medications such as corticosteroids and progestagens.
On the whole, being overweight and sedentary seem to be the two most common causes of DM.
Although DM is a serious disease, there are many ways in which it can be managed: ensuring the cat’s body weight remains normal, with the right diet and regular exercise could alleviate or even solve the problem. In more serious cases, cat owners will learn how to inject their cat with insulin if necessary and the cat will be able to enjoy a good quality of life.