Diabetes in Cats

Estimated Reading Time 6 minutes
Diabetes in Cats

If you think your cat has diabetes, you may be feeling scared and overwhelmed. Diabetes seems like a complicated disease, but with early detection and proper treatment, your cat may be able to lead a full, happy life. Continue reading to learn more about diabetes in cats, including causes, signs, and treatment.

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What is Diabetes?

Diabetes Mellitus is a disease that occurs when the pancreas has trouble producing insulin. Insulin is a hormone that helps cells absorb glucose (sugars) to fuel tissues and organs. Without insulin, a diabetic cat can eat food all day long and have tons of glucose trapped in their bloodstream, but they can’t use any of it! So, just like people, most diabetic cats need insulin injections twice a day so they can use the glucose they consume.

Usually, the kidneys help control glucose. However, diabetes causes the kidneys to become overwhelmed by the amount of sugar in the bloodstream, allowing the excess sugar to spill into the urine. Water follows the glucose and causes diabetic animals to urinate more than usual. Since this causes dehydration, animals then seek out more water and drink more than usual. It’s also common for diabetic cats to develop urinary tract infections since the glucose in the urine is an energy source for bacteria.

In the long run, without insulin injections (treatment), a cat will start breaking down its own body muscle to try to access glucose. The products of this process (ketones) are toxic to the body and can be fatal (diabetic ketoacidosis).

Causes of Diabetes in Cats

Cells are not able to readily utilize glucose from the bloodstream for energy use due to closed channels in their membranes. The role of insulin is to “open up” these channels and facilitate the uptake of glucose from the blood into different cells. The pancreas produces and secretes insulin depending on the level of blood glucose in the cat’s system. When blood sugar level shoots up, which usually happens after a meal, the pancreas is stimulated to produce and release insulin to help in the utilization of the glucose by different cells, tissues, and organs.

In the pancreas, there is a cell type called Beta cells that produces insulin. In some cats, there aren’t enough of these cells, or they aren’t producing enough insulin, or both. This is similar to Type II diabetes in people, ie. adult-onset, or “non-insulin-dependent” diabetes. In some cases, no insulin is being produced at all. This is similar to Type I diabetes in people, ie. juvenile-onset, or “insulin-dependent” diabetes. Cats most often have Type II diabetes.

Type I diabetes mellitus in cats is characterized by the total destruction of beta cells in the cat’s pancreas, the cells responsible for the production of insulin for carbohydrate metabolism. This is a rare type of diabetes in cats and results in an absolute deficiency of insulin in their system.

Type II diabetes mellitus is the most common type of diabetes in cats. It is described as partial damage to the insulin-producing cells of the pancreas. There is still insulin production but it is insufficient, and there is a delayed response to the cat’s blood glucose level. To a certain extent, cells also develop insulin resistance making carbohydrate metabolism inefficient. Obesity is a known predisposing factor in this type of diabetes in cats and working on your pet’s weight once diagnosed can help in the successful treatment of the condition. Certain medications, such as corticosteroids, can also lead to the development of diabetes in cats, and withdrawing these medications can help in the resolution of the disease..

Signs of Diabetes in Cats

The most common signs of diabetes are increased thirst, urination, and hunger. A cat may also experience weight loss and lethargy. Often diabetic animals start out as overweight and end up losing muscle mass, sometimes to the point of looking emaciated. This commonly occurs if the cat isn’t diagnosed and treated in a timely fashion. Fortunately, many, if not all, of these signs can resolve with treatment.

Diagnosing Diabetes in Cats

Diabetes Mellitus is diagnosed by having a repeatedly high glucose level in the bloodstream, glucose present in the urine, and other changes in bloodwork, combined with the clinical signs mentioned above. If you suspect your cat has diabetes, it’s important to have them diagnosed and begin treatment as soon as possible.

Treatment of Diabetes in Cats

Cats are different than all other animals because they can have ‘transient diabetes’. This means that SOME cats can revert out of being diabetic if treated appropriately and promptly. Think of this as being like Type II diabetes in humans – it’s referred to commonly as “non-insulin-dependent diabetes”. This means that it is possible, AFTER USING INSULIN TO GET THE CAT BACK ON TRACK, to wean them off of insulin once their pancreas begins secreting it appropriately. This should all be done with the supervision of your vet. However, there is never a guarantee that this “remission” will happen.


Insulin injections are typically given twice daily (every 12 hours), 30 minutes to 1 hour after a meal. Insulin doses are initially calculated by your vet. Then, based on your cat’s response, the dose may be adjusted over several weeks or months. Some cats become regulated on insulin quite quickly, and others need some fine-tuning.

It’s important to be patient when first starting insulin therapy for your cat. Never adjust any doses without consulting your vet. Many cats need to be on a newly calculated dose for 2-3 weeks before their response can be evaluated and adjusted.

There are different types of insulin, and your vet will choose the appropriate type for your cat. Part of treatment is continuing to monitor your cat’s response to insulin over time. Your vet may periodically ask you to drop your cat off for the day so that your cat’s glucose can be checked every 2 hours or so. This day-long test is called a Blood Glucose Curve. It helps show your cat’s response to insulin therapy throughout a typical day.

Your vet can explain and demonstrate to you how to store, handle, and administer insulin injections. The needles are very small, and surprisingly, most cats tolerate injections quite well.


Nutrition also plays an important role in managing the condition. A well-balanced diet, designed to regulate the digestion and absorption of carbohydrates, can help regulate and control blood sugar levels in a diabetic cat.

Controlling your diabetic cat’s diet is very important! Consult with your vet about prescription and over-the-counter options to feed your diabetic cat.

How to Prevent You Cat from Developing Diabetes

Don’t let your cat become overweight! There are dry food dispensing toys to slow your cat’s mealtime intake that force them to play/exercise to obtain their meal. There are low-cal and prescription metabolic diets that can aid your furry friend to lose a few pounds. Try to keep indoor cats exercised and entertained with wand toys, lasers to chase, and balls to play with.

Please understand that some cats that develop Type I diabetes may never have been overweight, and may still always need insulin.

When should you contact a vet?

If your cat has increased thirst, urination, hunger, or has had these signs for a while and is now losing weight, or is lethargic, dehydrated, and has a poor haircoat, your vet will need to run bloodwork or other lab tests to help diagnose the cause. Many diseases cause these types of signs, and your vet will need to know what’s going on in order to treat your cat properly.

Read more:

Kidney Failure in Cats

Hyperthyroidism in Cats

The Cat-Lover’s Guide to Litter Box Bliss

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