Cat diabetes is similar to human’s type 2 diabetes. It starts by insulin resistance caused by overweight or by the side-effects of some drugs. Amylin deposition causes the progressive destruction of the β cells of the pancreas and eventually impaired insulin secretion. Insulin, in small amounts, cannot regulate any more the increased glycemia in a proper way.
Unlike dogs, cats a remission may occur if they are treated soon enough, that is before the pancreas loses its capacity to secrete enough insulin. This stage of the disease is called non-insulin dependent diabetes mellitus (NIDDM). Lowering blood sugar in cats with NIDDM preserves the pancreas by limiting the need for endogenous insulin and by restraining amylin fibrils deposition.
Remission can be achieved within the 4-6 weeks after a non-insulin dependent diabetes mellitus has been diagnosed. Theoretically, a diet, low in energy and carbohydrates content with or without an oral hypoglycemic drug should be sufficient for obtaining remission. In practice, and because of the short window of opportunity, the vet will try to get quick result by prescribing insulin injection(s).
The latter stage of the disease is insulin-dependent diabetes mellitus (IDDM). The pancreas has lost most or all its β cells and will not be able to secrete insulin in suitable quantities. The diabetes is chronic and the cat will need lifelong insulin treatment.
As there is no obvious clinical difference between non-insulin dependent diabetes mellitus (NIDDM) and insulin dependent diabetes mellitus (IDDM), the strategy will generally be to try to achieve remission rapidly by adjusting frequently (every week) the insulin dose and the nature and quantity of food. Remission rates are good, between 30 to 50%.
If, at the end of the six-week period, remission is not obtained, the diabetes will be considered as chronic. The initial treatment will be continued and, if necessary, adjusted again. The goal of the treatment will be to limit the symptoms and to avoid the onset of complications. If good care is provided to the cat, it can live a long, normal and happy life.
Remission does not necessarily mean complete recovery: many β cells of the pancreas have been irreversibly damaged. Regular checkups including urine glucose measurements or a fructosamine test will be performed every month.
Insulin treatment consists of daily insulin injection(s). As there is a wide range of responses to insulin among cats, the injection frequency, the dose and mainly the type of insulin have to be tailored to each individual.
Type of insulin: insulins differ by their duration of action and their potency. The vet will have to choose between potent, short acting insulin and less potent long acting insulin. By increasing order of duration of action: NPH (Neutral Protamine Hagedorn), lente insulin, Vetsulin® (= Caninsulin in Europe®), ultralente insulin, PZI (Protamine Zinc Insulin) and glargine.
Number of injections: once a day, but more often twice a day
Injection site: under the skin of the cat (subcutaneous injection) usually in the back of the neck, alternatively in the flank.
One critical aspect of diabetes treatment is the occurrence of hypoglycemic episodes: blood glucose fall under the 60 mg/dL (3.33 mmol/L) threshold. Either because the insulin dose is too high, or you’ve given too much insulin, or the cat didn’t eat enough, or didn’t exercise enough, or even the cat’s response to the treatment has changed. You have to be especially attentive to the warning signs of hypoglycemia. They are mostly nervous in origin:
- Increasing anxiety
- Uncontrolled urination
- Confusion, disorientation
- Unstable locomotion
- Muscle twitching
- Stumbling or sinking of the rear legs
- Seizures or coma
In case your cat exhibit these symptoms, you will have to feed the cat a high-sugar treat that is quickly absorbed into the bloodstream, generally in syrup form. It will restore higher blood sugar level. You do not need your pet to swallow the food. The sugar will pass directly into the blood through the cat’s cheek or gum. You will also need to record the symptoms to inform your vet.
In the more severe cases or if the mild symptoms persist, you need to call your veterinarian immediately. If he/she is not available, do not hesitate to call a veterinary emergency service.
Short hyperglycemic episodes are less detrimental compared to hypoglycemic ones. In practice, and if there is doubt whether the correct dose of insulin has been administered, it is always better to risk hyperglycemia rather than hypoglycemia by postponing the next injection to the next predefined injection time.
The diabetic cat diet will rectify the nutritional mistakes that led to obesity or overweight. It lowers post-prandial blood glucose and decreases the needs of the organism for insulin. It usually contains little carbohydrates and fat, but high amounts of proteins and fibers.
The diet objective is to decrease the cat’s weight by 1% a week, without going too fast. The cat must be fed twice or three times a day and special attention should be paid to palatability and to possible food leftovers that may unbalance the treatment and lead to hypoglycemia.
See Food for Diabetic Cats page.
These drugs may be prescribed by your vet for restoring normal glucose regulation in cats with non-insulin dependent diabetes (NIDDM). However, they are very rarely used and their effectiveness is often poor. They help lower blood glucose in combination with an appropriate diet. They usually replace insulin injections for cats with mild symptoms. As insulin, they may prompt hypoglycemia and should be administered in strict respect of the veterinary recommendation.
Sulfonylureas (glipizide, glyburide) stimulate the secretion of insulin by the pancreas and improve cells sensitivity to insulin.
Meglitinides (repaglinidine) stimulate the secretion of insulin.
Biguanidines (metformin) and thiazolidinediones (rosiglitazone, pioglitazone) increase the sensitivity to insulin within the liver and the body cells, especially muscles cells.
Chromium and vanadium have the same mode of action as insulin. Their long term use is limited because they are metals and accumulate in the body.
Acarbose slows down the absorption of carbohydrates and glucose.
Exercise helps bring blood glucose down. Your vet will advise you to make your cat have some physical activity to balance the treatment. Encouraging a cat to do exercise is not easy task. You should take advantage of its natural hunting instinct. If your cat does not live outdoor, let it play with items that mimic preys such as balls, wands or strings. Be careful with strings or any other thing it can swallow to avoid intestinal obstruction. Cats also like climbing and jumping. If you have got enough room, you can offer it a cat tree, or rearrange some pieces of furniture, clear shelves…
By reading on all the aspects of cat diabetes treatment, you will easily understand that you will play a key role in providing care for your diabetic cat. You will become a true assistant of your vet. You will have to perform many tasks and interpret the changes in your cat’s behavior or symptoms:
- Give meals and insulin injections at precise times in the day
- Observe and note what part of the food has actually been eaten at each meal
- Make blood glucose measurements
- Record weight changes
- Keep a close watch on your cat’s symptoms and understand what they mean for preventing severe episodes
- Inform your vet regularly and plan proactively the next consultation