Feline Diabetes

What is Diabetes?

Diabetes mellitus is a medical condition in which the body fails to produce or properly respond to insulin, a hormone necessary for unlocking cells to absorb glucose, the primary source of energy. This leads to increased levels of glucose in the blood, which is detrimental to the body's well-being.

Just like human bodies, cats need glucose for energy, but glucose needs insulin to be transported from the bloodstream into cells. In Type I diabetes, there is a decrease in insulin production, resulting in high glucose levels. Type II diabetes, on the other hand, happens when cells in the body do not respond properly to insulin. In both cases, cells are deprived of nutrients despite high glucose levels in the blood.

Poplar, a RAL cat with diabetes. He is staying in foster care to monitor his glucose levels.

Cats are mostly affected by Type II diabetes, with estimates of 0.2% to 1% of cats being diagnosed with the disease during their lifetime. Risk factors for diabetes in cats include obesity, old age, lack of exercise, male gender, and the use of steroids to treat other illnesses.

Obesity is a significant risk factor for diabetes in cats. Keeping cats at a healthy weight and encouraging physical activity through play are the most effective ways to decrease the risk of developing diabetes. Cats weighing 13 pounds or more are at a high risk for developing type II diabetes mellitus.

The most common symptoms of diabetes in cats are weight loss despite a good appetite and increased thirst and urination and sometimes increased appetite.

How is it diagnosed?

To diagnose diabetes mellitus in cats, a veterinarian will check for persistently elevated glucose levels in the blood and urine, along with consistent clinical signs. However, a single blood glucose reading may not be enough in cases where stress hyperglycemia may be a factor. In such cases, a fructosamine concentration test can be helpful. The vet may also recommend other tests to rule out other diseases that could be contributing to the cat's symptoms.

How is it treated?

The main goals of treating feline diabetes are:

restoring normal blood glucose concentrations
controlling weight loss
reducing thirst and urination
avoiding low blood sugar due to treatment.

Insulin and dietary therapy are the best way to achieve these goals.

Injectable insulin is the mainstay of treatment for feline diabetes. There are different types of insulin that can be used for cats, and each has its pros and cons, so it's important to discuss with the vet which one is best for your cat. Insulin injections are given subcutaneously approximately every 12 hours, and a diet low in carbohydrates has been shown to improve blood sugar regulation in diabetic cats. Slow, controlled weight loss is important for overweight cats, and the timing of meals is controversial, although free choice feeding may be acceptable with a low carbohydrate diet. If food must be withheld for any reason, a reduced dose of insulin may be recommended with careful monitoring.

Monitoring

Monitoring is crucial in the treatment of diabetes in cats, and both the owner and the veterinarian should be involved. Regular monitoring helps determine the ideal insulin dose for each cat and avoid complications such as hypoglycemia, uncontrolled diabetes, and diabetic ketoacidosis. Assessments of weight, water intake, and appetite should be recorded regularly to determine if treatment goals are being met.

Blood glucose curves are the ideal method for monitoring blood sugar regulation during treatment. This involves checking the cat's blood sugar before receiving an insulin injection, then every 1-4 hours throughout the day to ensure that the average blood glucose stays within an acceptable range and does not drop dangerously low. Initially, blood glucose curves may need to be performed every few weeks, but they can be spaced out once the diabetes is more well-regulated. Even in a stable cat, blood glucose curves should be performed every 3-4 months, as insulin needs can change over time.

Eventually, owners may be able to learn how to perform blood glucose curves at home, which can give more accurate results and avoid stress for the cat. Blood can be collected from an ear vein or paw pad and read on a validated blood glucose monitor. Alternatively, veterinarians may use a continuous blood glucose monitoring system that records readings every few minutes for up to two weeks, but not all cats will tolerate it. It is essential that owners do not change their cat's insulin dose without consulting their veterinarian.

If performing a blood glucose curve is not possible, a fructosamine concentration test can provide a rough estimate of blood sugar control over the last two weeks with a single blood sample. However, this is not as ideal as blood glucose curves since it only measures the average blood sugar rather than highs and lows throughout the day.

Prognosis

There is no cure for feline diabetes, but with adequate management at home, the prognosis for a good quality of life is expected. Many cats will enter a state of diabetic remission with early and aggressive treatment, but if a cat has not entered remission within the first six months after diagnosis, it will require life-long insulin injections. Cats who achieve remission should continue to be monitored closely and fed a low-carbohydrate diet as they may require insulin therapy again in the future.

Sources:

Cornell Feline Health Center. (2018, July 23). Feline Diabetes. Cornell University College of Veterinary Medicine. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-diabetes

Diabetes Mellitus in Cats - Overview. (2015). Vca_corporate. https://vcahospitals.com/know-your-pet/diabetes-mellitus-in-cats-overview

‌