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DIABETES MELLITUS

First broadcast on www.provet.co.uk  


This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Diabetes mellitus is a common disorder in dogs, and not uncommon in cats. The disease can usually be controlled by a combination of medical treatment and dietary management and affected animals can expect to lead a relatively normal life. However, in some individuals it can be difficult to get satisfactory stabilisation.

Diabetes mellitus is common in humans and in pets in which it affects about 1 in every 200 dogs, and one in every 800 cats. It is most commonly seen  in middle-aged to old small dogs including Dachshunds, Poodles and Terriers, but it is also seen in larger breeds - Samoyeds and Rottweilers and others. Siamese cats are also thought to be predisposed to develop diabetes.

There are two basic forms of the disease :

  • Insulin dependant diabetes mellitus (IDDM)
    • This is due to a failure of the pancreas to produce sufficient insulin, and it can be present from birth, or develop later
  • Non-insulin dependant diabetes (NIDDM)
    • Insulin is produced in sufficient quantities by the pancreas, but it is unable to work because of resistance in body tissues. This "insulin resistance" can be caused by a variety of situations :
      • Obesity
      • Various diseases - eg heart failure.

In the body insulin helps sugar (as glucose) move into tissue cells where it is used to produce energy. If there is insufficient insulin present, or if the insulin that is present can not work because of tissue resistance, blood sugar concentrations rise. Eventually the sugar "tips over" into the urine, and this takes water with it. The result is an increase in urine production and because the animal is effectively losing water from it's body it needs to compensate and so it develops an increase in thirst. If your pet develops an increased thirst one of the disorders that your veterinarian will probably screen for is diabetes. Blood tests and urine tests will help to confirm the diagnosis.

Because the glucose in the blood can not get into the tissues that use it for energy (eg the brain), these tissues can't function properly. The animal eats more food (called polyphagia) in a vain attempt to increase glucose supply to it's tissues, even though there is plenty already in the bloodstream.

Many animals that develop diabetes are overweight initially - but because the tissues can not use the blood glucose  for energy, they breakdown their own body fat stores and protein to make energy...so animals with diabetes often lose weight during the course of their illness.

Even before they show any signs of diabetes, overweight dogs have impaired blood sugar control, and they have increased concentrations of insulin in their blood due to insulin resistance. In one large survey obese cats had over twice the risk of developing diabetes as non-obese cats. So keep your pet lean, fit and trim.

In pets treatment usually involves :

  • Regular insulin injections if the animal has IDDM
  • Reduce body weight if obese
  • Treatment of  any other disease that might be involved eg heart failure 
  • Dietary management

Some diets are much better for diabetics than others. For example, high fibre diets are usually recommended nowadays because they help to control the rate of sugar digestion and absorption into the body. Your veterinarian will advise on the best food for your pet.

It is important to stabilise your pet then continue with precisely the same dose of insulin and feeding protocol. If you change the type of food, the amount, or the timing of feeding, OR if you change the dosage or timing of insulin administration  you can easily destabilise the patient. For this reason you must stick to the advice that your veterinarian gives you if you have a pet that develops diabetes.

Other reasons why stabilisation may be difficult include :

  • Your pet may develop an immunity to the type of insulin being used
  • Your pet may have more than one disorder at the same time, for example older animals often develop:
    • obesity
    • renal failure
    • heart failure
  • Your pet could be destabilising himself (or herself) if he/she has access to foods that you don't know about
  • Sometimes owners have difficulty administering the insulin properly
  • If insulin resistance cannot be overcome the condition will progress

If the diabetes is not stabilised,  the high circulating glucose concentrations lead to liver disease, and the animal may eventually go into a coma and die.

 

Updated October 2013