Can cats suffer from diabetes and what are the symptoms?
An alarming number of cats are developing diabetes, which is the inability to balance blood sugar or glucose levels leading to hyperglycaemia (high blood sugar levels). Unlike humans, young cats rarely develop diabetes. It most often affects cats older than seven and males are more commonly afflicted than females. Obese cats are at higher risk and cats with underlying diseases such as pancreatic disease, hyperadrenocorticism (tumour of the pituitary or adrenal gland resulting in excessive production of corticosteroids by the body), and acromegaly (a tumour producing excessive amounts of growth hormone). Certain medications (for example corticosteroids such as prednisolone and progestogens such as megestrol acetate) can cause insulin resistance – the inability of insulin to enter the cell.
In general there are two types of diabetes. Type 1 is caused by insufficient production of the hormone insulin by the pancreas, whereas Type 2 is an inadequate response of the body’s cells to insulin, also called insulin resistance. Both types lead to hyperglycaemia (high blood sugar levels) and subsequent glucosuria (sugar in the urine), caused by insulin not being available or glucose not being able to be transported into cells.
Typical symptoms are: polydipsia (excessive thirst); polyuria (excessive urination); weight loss; polyphagia (increased appetite) without gaining weight; and neuropathy (weakness in hind legs). Diabetes mellitus is diagnosed based on the cat’s symptoms, laboratory test results, and the persistent presence of abnormally high levels of sugar in the blood and urine.
About 80 to 95% of diabetic cats experience something similar to Type 2 diabetes but are generally severely insulin-dependent by the time symptoms are diagnosed. Left untreated, it can lead to a dangerous, sometimes fatal condition called ketoacidosis, indicated by weight loss, loss of appetite, vomiting, dehydration, severe depression, problems with motor function, coma and even death. This is an emergency and the cat should be taken to the vet immediately for treatment.
Diabetes is a treatable disease that doesn’t have to shorten a cat’s lifespan. Most diabetic cats require an insulin injection administered under their skin twice daily. The injections can be given at home, preferably at the same time each day. Frequency of administration, the right type of insulin and dose are determined by your vet and need to be checked frequently as your cat’s requirements might change. Some cats might even go into remission and won’t need insulin anymore. This is commonly seen in heavily obese cats who have achieved good weight control, or in cats with underlying disease that are successfully treated.
A cat’s diet plays an important role in treating diabetes. Obesity is a major factor in insulin sensitivity, so if your cat is overweight, you will need to put her on a weight loss programme to gradually lose weight. A high-fibre, high-complex carbohydrate diet can not only achieve weight loss if necessary, but it also helps to control blood sugar levels after eating. (Underweight cats should initially be fed a high calorie diet until they reach their ideal body weight.) Some cats respond better to low-carbohydrate diets and one should try different diets to find the most suitable for your cat.
There is no cure for diabetes, but with dedication and close communication with your veterinarian, you can successfully manage your diabetic cat and give her many healthy years to live.
Dr Isabelle Schlunken, Bluehills