Diabetes mellitus in cats

What is diabetes mellitus?

Diabetes mellitus is a metabolic disorder in which blood sugar levels are permanently elevated because either:

• insulin is not produced in sufficient quantities (type I diabetes), or
• the body no longer responds properly to insulin (insulin resistance—type II diabetes)

Insulin is produced by the pancreas and is responsible for ensuring that sugar can be absorbed into the cells and used there as energy. If this mechanism does not work, blood sugar levels remain too high.

In cats, the disease corresponds to type II diabetes in over 80% of cases, characterized by insulin resistance and a reduction in beta cell function. A vicious cycle of obesity, inflammation, amyloid deposits, and glucose toxicity leads to the gradual depletion of insulin-producing cells. This process is initially reversible, but later becomes irreversible.

risk factors

• Obesity: is the most important factor for insulin resistance in cats. Obese cats have significantly reduced insulin sensitivity and are much more likely to develop diabetes.
• Chronic pancreatitis: more than half of diabetic cats show histological evidence of pancreatitis.
• diabetogenic drugs (e.g., glucocorticoids, progestogens)
• Hormonal disorders, especially hypersomatotropism, hypercortisolism, and hyperthyroidism
• Lack of exercise, age > 7 years, male neutered cats (male cats develop insulin resistance more quickly)

Typical symptoms

Many cats display the classic combination of symptoms

• Polyuria – increased urination
• Polydipsia – excessive drinking
• Weight loss despite a healthy appetite
• shaggy coat
• In some cats: plantigrade gait (diabetic neuropathy)

Our tip: If you suspect diabetes, it is worth getting a professional initial assessment, especially if the above symptoms are new. As a Calingo customer, you can reach a veterinary professional 24/7 (via chat, phone, or video) without an appointment.

diagnosis

The diagnosis of diabetes mellitus in cats is based on several tests. A single high blood sugar measurement is often not conclusive, as cats can quickly become stressed at the vet, which causes blood sugar to rise sharply and may have nothing to do with diabetes. The fructosamine value is therefore decisive, as it reflects the average blood sugar level over the last 1–3 weeks and helps to distinguish stress hyperglycemia from true diabetes.

A urine test provides additional information, such as the presence of glucose or ketone bodies. However, glucose can also appear in urine due to stress, which is why urine analysis must always be evaluated in combination with blood values.

Imaging techniques such as ultrasound and X-rays support the diagnosis by revealing comorbidities that frequently occur in diabetic cats. These include, for example, pancreatitis or hepatomegaly (enlarged liver). Such diseases can be both a cause and a consequence of diabetes and have a significant impact on the course of the disease and its treatment.

Treatment

The standard treatment for feline diabetes mellitus continues to be the administration of insulin by injection, usually twice daily. The insulin dose is adjusted individually, ideally based on daily profiles or continuous glucose monitoring.

An oral antidiabetic drug has been available for cats for several years:
The active ingredient velagliflozin is an SGLT2 inhibitor that increases glucose excretion via the kidneys. This drug is not suitable for all diabetic cats and is clearly linked to certain conditions.
It may only be used in cats that do not have ketosis (i.e., no ketone bodies in the blood or urine), are sufficiently hydrated, and are in stable general health.

Switching to a "diabetes diet" is recommended for all cats with diabetes. This involves ensuring that their diet is high in protein and low in carbohydrates (wet food usually contains fewer carbohydrates than dry food). Sufficient exercise is also important for slow and healthy weight loss.

Managing diabetes: not always easy

At the beginning of treatment, it is important to visit the vet regularly in order to control the diabetes as quickly as possible. The daily glucose curve, which can be measured at the vet's office or at home, is important here. New continuous glucose monitors enable close monitoring, less stress for the cat, and better and faster control.
Sometimes diabetes is difficult to control despite monitoring and increasing the insulin dose. This may be due to other hormonal disorders that cause severe insulin resistance, such as acromegaly, active pancreatitis, or hypercortisolism.
There are also medications that have a diabetogenic effect and influence blood sugar levels (e.g., prednisolone).
Incorrect use of insulin (incorrect mixing, storage, or dosage) also plays a major role.

What happens when your metabolism goes haywire?

Diabetic ketoacidosis is, so to speak, the final stage and therefore a life-threatening emergency with a relatively high mortality rate. It is caused by absolute insulin deficiency, an increase in stress hormones, and massive ketone body production. Typical symptoms of diabetic ketoacidosis include a reduced general condition, even to the point of coma, severe dehydration, vomiting, and rapid and deep breathing. The treatment of diabetic ketoacidosis is intensive care and includes fluid therapy, electrolyte balance, insulin administration (but only once the patient is hydrated), and other measures depending on the underlying disease and condition.

Can a cat be cured?

Yes—cats have a remarkably high chance of going into remission compared to dogs.
According to the literature, about 20–30% of cats with diabetes mellitus experience a transient course and no longer need insulin after some time.
With early diagnosis, an appropriate diabetic diet, and consistent insulin therapy, this rate can even rise to 50%. The main reason for remission is the recovery of the beta cells in the pancreas after glucotoxicity has been eliminated.
Excessively high blood sugar levels directly damage the beta cells and lead to reduced insulin production. If blood sugar is consistently lowered over a period of several weeks, the function of the cells can partially or completely regenerate—especially in the early stages of the disease.
Even if a cat is in remission, it is still considered "at risk for diabetes."
A relapse is possible, especially if the cat becomes overweight again, receives diabetogenic medication (e.g., prednisolone) for a long period of time, or develops pancreatitis or other hormonal disorders.

Unfortunately, untreated diabetes in cats can be fatal because the metabolism completely derails over time. However, with good veterinary care and consistent therapy, diabetes can be managed very well in most cases.
Experience shows that the initial concern about the first insulin injection—which almost every cat owner is familiar with—quickly subsides. Most animals accept the treatment without any problems, and many owners report after a short time that everyday life with insulin is much easier than they had initially imagined.
With patience, routine, and the right support, a diabetic cat can lead a long and happy life.

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Insurance coverage for diabetes

Whether it's assessment, diagnosis, or treatment—diabetes often involves several different aspects. With Calingo, your cat and the associated veterinary costs are covered within the scope of your chosen coverage and the insurance terms and conditions. Put together the right cat insurance for your furry friend here.