Diabetic complications in cats

Diabetes is a relatively common disease in people and is being recognized more frequently in pets. If untreated the disease has serious effects and will ultimately result in the death of your pet. The good news is that most diabetic animals can be successfully treated and many live normal, happy lives. However, caring for a diabetic pet takes a good deal of time and effort to make sure their disease is well controlled, and poorly controlled disease can lead to a variety of complications.

High levels of sugar in the blood can result in consequences which can severely impact your pet’s quality of life. These include the problems you probably first noticed in your pet such as weight loss, drinking excessively and increased appetite. Cats with poorly controlled diabetes also tend to have poor general health and low immunity, which can increase the risk of infections. The presence of diabetes can also lead to complications when a cat develops another health problem, whether it is a simple gastrointestinal upset or something more serious. In that case, diabetic pets may become suddenly very ill with high blood sugar levels. and they might develop a condition called ketoacidosis or ketosis. This is a life-threatening emergency and urgent veterinary help might be needed to save your pet’s life. Therefore, it is recommended that your pet receives prompt veterinary attention at the first sign of any illness.

Hypoglycemia (low blood sugar)

If blood sugar levels drop too low (this is often called a ‘hypo’ attack), your pet may have episodes of wobbliness, confusion and ultimately could collapse. Some diabetic cats are more prone than others to low blood sugar. Most episodes of low blood sugar only result in mild signs such as confusion or wobbliness; however, in some cases, low blood sugar levels can result in more serious signs of seizures, coma and death. These attacks can occur because of overdose of insulin or under feeding. Hypoglycemia may cause clinical signs of hunger (not as obvious in cats), hiding, nervousness, restlessness, disorientation, ataxia and coma which can be life-threatening.

If your pet suffers a hypo attack your veterinarian will recommend dropping the insulin dose to three-quarters or less than your pet was getting before. If hypoglycemia is present for a long time, then other complications can develop.

Diabetic ketoacidosis (DKA, ketosis)

Diabetic ketoacidosis (DKA) is most often seen in cats that have not yet had their diabetes recognized but can also occur in cats receiving insulin treatment if the dose of insulin is too low or the insulin is not working properly. In almost all cases there is another disease or condition in addition to the diabetes that triggers the DKA to develop. In normal animals, blood sugar levels rise after eating. Insulin is released and this helps the tissue to take up the sugar from blood to use as an energy source. In diabetic animals the insulin is not present, or not working effectively, and the cells cannot use the sugars. Tissues are starved of fuel and so they switch to using fats instead of sugar. The rapid breakdown of fat to use as an energy supply, results in the production of ‘ketones’ which can be toxic to the body.

Over a short period of time, your cat may become unwell with vomiting and depression. There may also be signs of another underlying condition, such as a urinary tract infection or liver disease with yellowing of skin and gums (jaundice), or kidney disease. The signs of DKA usually develop within a few days and your pet may go downhill very rapidly.

Diabetic neuropathy

This is the most common problem associated with diabetes in cats, affecting 1 in 10 poorly controlled cats. The nerves that detect sensation in the limbs become damaged initially and you may notice your cat is walking unusually on its back legs. They may start to walk on their heels like a rabbit. The condition usually gets worse over several months and your cat may stop jumping and eventually become weak or wobbly on its back legs. It is very important to get advice from your veterinarian if you notice this condition developing because, if the diabetes can be stabilized quickly, the changes that are present may even resolve with time.

Kidney disease (diabetic nephropathy)

This is a rare, but serious, complication of feline diabetes. Prolonged high blood sugar levels cause damage to the kidney. The signs of this are the same as chronic kidney disease which is common in geriatric cats so it can be difficult to distinguish between the two conditions.

Cataract

Diabetic cataracts in cats tend to be much less severe than those seen in poorly controlled diabetic dogs, and blindness is rare. Cats that develop diabetes at a very young age may be more likely to develop cataracts.

Diabetic retinopathy

Diabetic retinopathy has occasionally been reported in dogs and cats, but it fortunately does not cause the same problems as in people with diabetes. High blood sugars cause damage to small blood vessels and over time, if your pet is not well stabilized, there may be a reduced blood supply to the retina at the back of eye. The retina is the area of the eye that detects light and so if it is damaged vision may be affected. Blindness due to damage to the retina is rare in diabetic animals.

To reduce the risk of your pet developing other conditions alongside its diabetes it is important to try to keep blood sugar levels well controlled. This can only be achieved by careful monitoring and regular discussion with your veterinarian on how your pet is progressing.