Over-weight dog with diabetes

Diabetes

The most common form of diabetes in dogs is diabetes mellitus or sugar diabetes, which occurs due to either a lack of production of insulin by the dog's pancreas or because of an insensitivity to insulin – the hormone that regulates the blood's glucose levels, the body's main source of energy.

An affected dog is not able to control glucose concentrations in its bloodstream. These blood concentrations can increase to such a level that glucose is eventually excreted via the kidneys into the dog's urine. This glucose-containing urine takes water with it and this leads to an excessive loss of water. This is compensated for by thirstiness and increased water consumption. This increased water consumption (also known as polydipsia) and consequent increased urination (polyuria) are common clinical signs seen in dogs with diabetes.

Additionally, dogs with diabetes will tend to lose weight as they burn through stores of fat and muscle trying to make glucose. Other symptoms observed in diabetic dogs include cataracts, polyphagia (increased appetite), exercise intolerance and recurrent infections.

When fat is burned to make glucose in the body, compounds called ketones are also produced. If diabetes goes undiagnosed and untreated, high levels of ketones in the bloodstream build up, resulting in ketoacidosis, which makes the dog very unwell and requires intensive treatment.

Why/how do dogs get sugar diabetes?

The exact cause is not clear, but it's likely several factors are involved:

Genetics

Certain breeds of dogs tend to have a higher incidence of diabetes, such as Golden Retrievers, German Shepherds, Miniature Schnauzers, Keeshonds, Poodles.

Obesity

As in humans, obese dogs have a higher risk.

Other illnesses and infections

Dogs will sometimes get diabetes as a direct result of being afflicted with another illness or infection. Certain diseases, especially the ones affecting the pancreas, may trigger an abnormal production of insulin. For example, Pancreatitis (inflammation of the pancreas) may result in the destruction of the cells in the dog's pancreas that are required for blood glucose regulation, which may then lead to diabetes mellitus.

Steroid drugs

Dogs that are on prolonged courses of steroids may eventually develop diabetes. Steroids can affect the normal functions of the pancreas, thereby slowing down the production of insulin in the body.

How is diabetes diagnosed?

Diabetes can be confirmed through blood and urine tests, which will show high concentrations of glucose in the blood and urine (hyperglycaemia and glucosuria respectively), as well as high ketone levels.

How is diabetes treated?

In cases where the underlying cause cannot be diagnosed, diabetes cannot be cured, it can only be managed. As with diabetes in humans, this is commonly done with insulin, as well as special dietary and exercise regimens.

Unfortunately, there is no standard insulin dose that can be applied to all dogs. Each diabetic animal has to have its dose tailored to its individual needs, which is worked out by a veterinarian. This may require a dog to be hospitalised for frequent blood and/or urine test for a day or two at a time.

Insulin used to manage diabetes in dogs comes as an injection, which is administered to the dog once or twice a day. Once the correct dose for your pet has been established, maintenance doses of insulin should remain relatively constant. In order to use insulin to achieve stable control of a diabetic animal's blood glucose levels, all the other factors that affect blood glucose concentration must be kept constant from day to day. These factors include the composition, volume and timing of meals, as well as the amount of exercise the animal gets.

It has been suggested that foods with a low glycaemic index are better choices for diabetic dogs (just as is the case with humans) as they improve overall blood glucose control. In general, diabetic dogs should be fed a diet high in complex carbohydrates and fibre to promote slow glucose release into the bloodstream. Dry food usually contains higher amounts of fibre so are usually preferred for diabetic dogs.

Commercial 'prescription' diets for diabetic dogs are also available. These diets are usually balanced in respect to fibre and glycaemic content, as well as the other nutritional requirements of a dog. If you choose to feed your dog a homemade diet, be sure to make the food consistent every day to avoid unnecessary fluctuations in blood glucose concentrations.

In general, it is recommended that your dog eats at least a small amount of food prior to any insulin injection so that you can see whether your dog is feeling well and eating normally before the insulin is administered. It's also recommended that meals are divided into approximately equal portions so that glucose concentrations don't dip too low in the afternoon.

Regular check-ups with your vet are required to check that the insulin dosage, diet and exercise regimen continue to keep the blood glucose level in check.