Diabetes Mellitus in Cats and Dogs

Written by Jess Wilson

Like humans, cats and dogs can be afflicted by diabetes! Diabetes Mellitus is a condition where the pancreas doesn’t produce enough of a hormone called insulin. Insulin is required by the body to transfer glucose from the bloodstream to the body’s cells to use as energy. When the body doesn’t produce enough insulin or can’t use it properly, glucose levels in the blood rise causing hyperglycaemia. If left untreated, high levels of glucose in the bloodstream can spill over into the urine (glucosuria) which causes increased water loss seen as increased urination and therefor thirst.

When the cells cannot use glucose for energy it forces the liver to break down muscle and fat into ketones for energy. This process can cause weight loss even when dietary intake is adequate or increased and high levels of ketones in the blood and urine (ketoacidosis) can be life-threatening.

Diabetes can be detected by clinical signs and blood and urine testing. It is treatable with insulin, special diets and regular monitoring.

Signs to look out for:

  • Increased thirst/urination
  • Weight loss despite good appetite, or anorexia
  • Sweet smelling breath
  • Vomiting
  • Chronic or recurring infections
  • Cloudy eyes
  • Collapse (medical emergency)

Once diagnosed your vet will start your pet on a calculated dose of insulin which is administered by an injection under the skin, usually twice a day.  Your vet or vet nurse will teach you how to do this so you can continue treatment at home. The needles are very small and usually well tolerated by both cats and dogs. After a period of time (usually two weeks) on insulin, your pet will need a glucose curve which is a series of blood tests (only a drop of blood needed) throughout the day to monitor the body’s response to the insulin by measuring blood glucose levels.  Your pet’s insulin dose will be adjusted according to the results and they will need regular glucose curves until the correct dose of insulin is found.  In some cases, blood glucose monitoring can be carried out at home via regular skin pricks (just like in humans) or a longer-term monitor attached to your pet. Regular checks are important, especially if your pet is showing signs of low blood sugar (hypoglycaemia) which may mean they are receiving too much insulin or going into remission.

Signs of hypoglycaemia can include:

  • Lethargy
  • Weakness
  • Muscle spasms
  • Trembling
  • Blindness
  • Loss of appetite
  • Collapse

If your pet displays any symptoms of diabetes you should book in for a health check. Diabetes can occur at any age, however overweight and older pets are more at risk of developing it and certain breeds of dogs may be predisposed. Your pet can live a long and happy life with well-controlled diabetes!