A vet’s guide to diabetes in cats

Diabetes mellitus in cats is a common endocrine disease, where the body can’t efficiently regulate blood sugar metabolism. It’s a complex chronic disease that requires careful management, constant monitoring, and life-long therapy.

It is estimated that the prevalence of diabetes in cats is 1 in 200 cats, but it can be higher in reality. Let’s just say that every veterinary practice has a few diabetic patients. 

Most cases occur in middle-aged or older cats. There also seems to be a certain breed predisposition for Burmese cats, but any breed can be affected.

Sadly, it seems that the number of cases is continually increasing year by year. This may be due to several factors such as increased incidence of obesity in cats or their longer life span. 

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While I am a veterinarian, this article is not intended to replace professional veterinary advice. If you have any medical concerns about your pet, consult your vet immediately. Always seek professional assistance if you are unsure of your pet’s health.

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What causes diabetes in cats?

Most people know that diabetes has something to do with insulin and blood sugar. So why is diabetes such a big problem?

Because animal bodies run on glucose, the same as humans. It’s the source of energy for the cells, the fuel for the body. Cells need to be able to process glucose, otherwise, they cannot function. This is where insulin comes into play. Insulin is a hormone that regulates glucose levels in the blood and its absorption into cells. 

What is the pancreas and why is it important?

The pancreas is a vital organ that lies on the right side of the abdomen. It’s technically a gland with exocrine and endocrine functions. As an endocrine gland, it produces the hormones insulin and glucagon, responsible for regulating the glucose level in the blood. As an exocrine gland, it produces enzymes that aid digestion in the small intestine.

Thanks to this duality, we see different diseases, depending on which part of the pancreas is affected. Problems in the endocrine part can result in diabetes mellitus. Problems in the exocrine part result in pancreatitis – the inflammation of the pancreas. 

So insulin is a hormone that is produced in the pancreas. It regulates the sugar blood levels and glucose resorption in cells. In other words, it “tells” the cells to grab glucose from the blood and use it as an energy source. 

In the case of diabetes, the cells cannot absorb glucose from the blood and use it as an energy source. Since the cells are not absorbing glucose from the blood, it builds up in the bloodstream and we can measure elevated blood sugar levels. So the cells don’t have enough glucose even when they need it and there’s too much in the blood.

Now, there are 2 types of diabetes in cats:

• Type I. diabetes or Insulin-deficiency diabetes happens when the pancreas isn’t producing enough insulin. It can be absolute (no insulin is produced) or relative (not enough insulin is produced). This is the most common form of diabetes in dogs. 

• Type II. diabetes or Insulin-resistant diabetes happens when the cells stop responding to insulin. It means that enough insulin is produced in the pancreas, but the cells are not absorbing glucose from the blood. This is a rare form of diabetes in dogs, but the most common (or almost exclusive) form of diabetes in cats.

However, nothing is black and white, and sometimes we can see a combination of these 2 types, where the cells aren’t responding to insulin and not enough insulin is being produced.

Risk factors for diabetes in cats

Diabetes usually occurs in older cats. Males seem to have a higher occurrence than females.

Any breed can develop the disease, there seems to be no breed predisposition. With one exception – the Australian Burmese cat. 

Obesity is a proven risk factor for insulin-resistant diabetes in cats.

Pancreatitis and some other diseases can also lead to diabetes. 

Risk factors for diabetes in cats:

• Age – older cats have a higher occurrence
• Sex – male cats seem to have a higher occurrence than females.
• Obesity
• Other health conditions – Pancreatitis, Cushing disease, some autoimmune disorders, viral diseases…
• Long-term use of corticosteroids
• Genetics seems to play a role in Burmese cats

What are the symptoms of diabetes in cats?

In the case of uncomplicated diabetes, the usual symptoms are increased thirst and urination, and increased appetite but at the same time weight loss.

Diabetes in cats often develops slowly and gradually, so owners often don’t recognize the signs at the beginning, especially if the cat spends a lot of time outdoors.

The body is trying to “feed” the cells, which are starved for glucose. However, the cells cannot absorb the energy they so desperately need. So the body starts to break down its fat and protein reserves as an alternative energy source. That explains hunger and weight loss at the same time. 

In medicine, you can say that too much of anything is poison. Even too much of the “good” and necessary stuff. Too much glucose in the blood is damaging to the organs, especially kidneys, heart, eyes, blood vessels, or nerves. 

Common signs of diabetes mellitus in cats:

• Increased thirst
• Increased urination
• Increased appetite
• Weight loss
• Muscle mass loss
• (signs of other underlying health conditions)

Signs of more advanced diabetes in cats include:

• Loss of appetite
• Lack of energy, weakness, and later lethargy
• Vomiting and/or diarrhea
• Seizures
• Collapse or coma

Uncontrolled diabetes in cats leads to organ damage and can cause:

• Recurrent or persistent infections
• Damage to the kidneys resulting in kidney failure
• Enlarged liver
• Diabetic ketoacidosis

A common complication of diabetes in cats is lower resistance to bacterial and fungal infections.

A dangerous form of decompensated diabetes mellitus is diabetic ketoacidosis. It’s a potentially life-threatening condition that requires rapid medical intervention❗️Your cat might display signs like rapid breathing, lethargy, vomiting, and/or sweet-smelling breath. 

Diagnosis of diabetes in cats

Diabetes in cats results in high blood sugar levels (hyperglycemia) and glucose in urine (glycosuria), even when the cat is fasting. Both glucose in the blood, as well as glucose in the urine, can be measured with a simple test. 

We all know that cats are special, so there is always a “but” 😩 They can display something called stress hyperglycemia, which can complicate the diagnosis. If a cat is under stress, it can rapidly increase her blood glucose levels.

So when we are struggling with the cat to get the blood sample, we will get high glucose levels, even when she’s not diabetic. It’s therefore recommended to take the sample (actually just a drop of blood from the ear or footpad) at the beginning of the physical examination when she’s still at least a little bit in a tolerant mood.

Sometimes other tests and diagnostic tools are needed to assess the damage to different organs. 

Treatment of diabetes in cats

Diabetes cannot be cured, but it can be successfully managed. However, the treatment requires more than just insulin injections. 

Successful management of the disease depends on 2 key factors:

• excellent communication between the vet and the owner
• full cooperation of the owner

If this doesn’t work, the treatment won’t work, sorry 🤷‍♀️

If the owner doesn’t fully cooperate, the cat will never be stable. If the communication between the vet and the owner doesn’t work, the owner won’t fully understand what’s going on. 

If you don’t trust your vet for whatever reason, or if your vet doesn’t have good communication skills (yeah, I know this does happen), find a different vet you can trust.

A cat with diabetes needs 4 things to have a happy life:

• daily insulin injections
• dietary management and individual nutrition plan
• frequent and regular monitoring (by both the owner and the vet)
• exercise to maintain her weight

🔻 Insulin 🔻

A cat with diabetes mellitus needs daily insulin injections. The shots go under the skin. I know a lot of owners have a problem with it at first, but believe me, once you get over the trembling hands phase, it’s not so hard ☺️

In some cases, the cat can receive oral medications, but they have some side effects and work only in special cases.

🔻 Nutrition🔻

Another important component of disease management is nutrition. 

You will need a whole dietary management plan. It’s not just what should you feed your cat, but also how often, how much, and how long should you wait after the insulin injection…

It needs to be tailored to your cat’s needs. If your cat is obese, she needs to lose weight safely. If she’s underweight, she needs to gain weight safely. There are guidelines on proper feeding times depending on the time of insulin administration. There are guidelines on how much fiber, protein or carbohydrates should a cat with diabetes get. 

🔻 Monitoring🔻

Frequent monitoring is another key element of the treatment of diabetes in cats. Depending on the results, the insulin dosage might change, your whole nutrition plan might change, even your monitoring frequency might change… and when you think the cat is finally stable it will probably change again 😕

This doesn’t mean that the changes have to be bad, it just means you need to be aware of them and adapt your therapy plan accordingly. So be prepared for frequent visits to the veterinary clinic at the beginning for medication adjustments.

Glucometers (devices that measure blood glucose levels) and urine strips (for monitoring glucose and ketone levels in urine) are effective tools that will help you monitor your cat at home. 

Now, most owners look at me with panic in their eyes when I mention urine testing. How do you collect a urine sample from a cat?? 🙀 Don’t worry, we have a few tips on how to do it without trying to get your cat to pee in a sample cup 😛 You can just replace the normal cat litter with specially designed urine collecting pellets or with clean and washed aquarium gravel. These materials will not soak up any urine, which can then be collected into a clean container for testing. A bit messy, I know, but still better than the sample cup 🤷‍♀️

🔻 Excercise🔻

Keep your cat active. It’s not just a great way to maintain her ideal body weight, but also a nice way to spend time with her 🙂 ❤️

I said it before, and I say it again – communication with your vet and your cooperation are the most important things for the successful management of this complicated disease. 

How long do cats live with diabetes?

Diabetes in cats cannot be cured, but it can be managed successfully. In most cases, this depends on you, the owner. If your kitty’s diabetes is regulated, and the treatment and monitoring are frequent and consistent, the prognosis is good. 

Sometimes cats even go into remission, where they won’t be needing insulin anymore. This does not mean that the disease has been cured and you can just forget the whole thing. You still have to take care of your cat’s diet and lifestyle and she might need insulin again in the future.

Diabetes in cats is a disease that requires life-long treatment and consistent monitoring. It’s impossible to treat it successfully without the full cooperation of the owner. You need to do what the vet tells you to do. You need to trust your vet. Otherwise, it just won’t work and your cat will be the one who will pay for it with her health and potentially her life. 

If diabetes is regulated and monitored, there is no reason why your cat shouldn’t have a long and happy life. Trust your vet, trust yourself, and trust the process ❤️

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References:

• Panciera DL, Thomas CB, Eicker SW, Atkins CE. Epizootiologic patterns of diabetes mellitus in cats: 333 cases (1980-1986). J Am Vet Med Assoc. 1990 Dec 1;197(11):1504-8. PMID: 2272886.
• Rand, J. S., & Marshall, R. D. (2005). Diabetes mellitus in cats. Veterinary Clinics of North America: Small Animal Practice, 35(1), 211-224. https://doi.org/10.1016/j.cvsm.2004.10.001
• Rand JS, Bobbermien LM, Hendrikz JK, Copland M. Over representation of Burmese cats with diabetes mellitus. Aust Vet J. 1997 Jun;75(6):402-5. doi: 10.1111/j.1751-0813.1997.tb14340.x. PMID: 9247686.