Understanding diabetes in pets

Did you know that November is National Pet Diabetes Month?

Diabetes is a chronic disorder that prevents your pet from properly producing or using insulin, a hormone that helps the body convert glucose (sugar) into energy. Because a diabetic pet’s cells don't receive the right amount of glucose, diabetes impacts all body systems. 

How common is diabetes in cats and dogs?

"Unfortunately, because of the human obesity problem in this country, we also have a pet obesity problem, and overweight pets are just as prone to diabetes as overweight people," said Mark D. Freeman, clinical associate professor of community practice at the Veterinary Teaching Hospital in Blacksburg.

He noted that genetic factors can play a role as well: "Unfortunately, there seems to be a bit of a genetic component. Some cats are just genetically predisposed. Dogs less likely."  

How is insulin produced?

Let’s start with a quick primer on the pancreas.  

The pancreas is an organ that serves several important functions — it produces a wide array of chemicals, including digestive enzymes and compounds that help the body absorb vitamins. 

Within the pancreas, small groups of cells called islets contain alpha, beta, delta, and epsilon cells. Each of these cells synthesizes a different hormone, but when it comes to diabetes, the most relevant cell is the beta cell, which produces insulin.  

Insulin is a very important hormone — it controls glucose delivery to the body’s tissues, enabling cells to take in glucose to use as fuel. Without enough insulin, glucose accumulates in the blood, unused.

A healthy pancreas senses the amount of glucose in the blood, and it secretes insulin or other, glucose-increasing hormones to maintain the optimal level of blood glucose. Basically, the pancreas performs a glucose-balancing act, producing hormones like insulin to control blood sugar levels.  

Diabetes mellitus — or just diabetes for short — occurs when something goes wrong with your pet’s insulin levels.

Types of diabetes in pets 

Like in humans, there are multiple types of diabetes in cats and dogs, and each has its own mechanism.

Insulin-dependent diabetes, also known as type 1. With type 1 diabetes, the pet’s immune system attacks the beta cells. This form can also be caused by damage to the pancreas, like through pancreatitis.  

Because the beta cells have been destroyed, the pancreas cannot produce the insulin the pet needs. 

Most pets with diabetes have type 1, and it’s overwhelmingly the most common type of diabetes in dogs.  

Non-insulin dependent diabetes, also known as type 2. Pets with type 2 diabetes have insulin resistance, where insulin cannot bond properly with insulin receptors. With type 2 diabetes, the beta cells remain intact, but the pancreas cannot secrete enough insulin to maintain a healthy level of blood glucose. 

Type 2 diabetes is more common in cats.  

Signs of diabetes in pets

Clinical signs of diabetes include: 

• Weight loss

• Cloudy eyes (cataracts) in dogs 

• Chronic infection

• Lethargy 

• Decreased appetite, especially in cats

One very common sign of diabetes is increased thirst and urination. When there is too much sugar in the blood, the kidneys attempt to remove the extra sugar from the body, producing more urine to flush the sugar out of the body. Because of the constant need to offload that extra sugar through urination, the kidneys demand more and more water, resulting in increased thirst.  

Treatment for diabetes 

If not properly managed, diabetes can severely harm your pet’s quality of life. Untreated diabetes can result in life-threatening diabetic ketoacidosis, where the body can’t access blood glucose, so it starts to break down free fatty acids instead. 

To diagnose diabetes, your veterinarian will test your pet’s blood and urine.

There are two main ways to manage your pet’s blood glucose levels: diet/exercise and insulin.  

A diabetic dog’s diet should be high in fiber and complex carbohydrates, and a cat’s should be high-protein, low-carbohydrate. Exercise helps lower insulin requirements and encourages better glycemic control.

Insulin administration 

Diabetic pets need insulin to keep their blood glucose in check. Pets usually require two doses of insulin a day with their food. A regular routine is crucial to maintaining healthy blood glucose—irregular feeding and insulin treatment can throw off your pet’s levels.

For pet owners concerned about giving insulin shots, Freeman offers reassurance: "Those insulin needles are so tiny that for most pets, if you give them a little bit of food of some sort while you're administering the insulin, or do it at mealtime, they don't even know they got poked."  

Regular checkups are needed to make sure your pet’s diabetes is managed well. Your veterinarian will adjust the insulin dose as needed to keep your pet healthy.  

Through insulin and a good diet, some cats go into diabetic remission and no longer need insulin treatment.