“My pet seems to be drinking a lot of water and has always been a good eater, but for some reason seems to be losing weight recently.” This is a comment I hear often in veterinary clinics when I’m talking to owners about their dog or cat’s behaviors at home. Many people are familiar with the term diabetes and use it loosely because they believe it to be a disease related to obesity or eating too much junk food. Diabetes mellitus is actually a more complicated metabolic disease than that, and not exactly the same as it is in humans.
Humans have two main forms of diabetes: juvenile and adult onset, or, as they’re more commonly referred to, insulin and non-insulin dependent. Gestational diabetes is another, but outside the scope of what animals have. Type I insulin-dependent diabetes is more like the type that animals have, which makes them insulin dependent for life.
Diabetes mellitus is caused by a decreased production in certain cells of the pancreas. The pancreas is an organ that lies near the stomach and beginning of the small intestine, whose main function is to secrete the hormone insulin into the blood. Insulin regulates the body’s amount of glucose utilized in the body. The pancreas has other functions, but this is the most important in terms of diabetes.
Because of this decreased production of cells in the pancreas, the body cannot properly utilize glucose (blood sugar), thus an excess of it is present in blood circulation, resulting in hyperglycemia. The surplus of glucose cannot be resorbed properly, thus an excess is filtered through the kidneys causing glucose to spill into the urine or glucosuria. This then triggers the body’s thirst mechanism to increase (polydipsia) with resultant increased urination (polyuria). The body then goes into a negative calorie balance because of the inability to utilize glucose properly. Thus it starts breaking down tissue in the body like muscle, causing the pet to be hungrier (polyphagia) but still lose weight.
In terms of risk factors, obesity is certainly a concern—certain breeds such as terriers, schnauzers, poodles, and bichons frises are commonly affected, and any breed of cat can be affected, as well as pets suffering from chronic, recurrent pancreatitis.
So, to recap: the four key signs of diabetes mellitus in pets are: polydipsia, polyuria, polyphagia, and weight loss despite having an appetite. These are the main symptoms owners will observe at home. I have personally owned two dogs with diabetes and am very aware of the challenges and management of this disease.
To diagnose diabetes mellitus, your veterinarian will have an indepth conversation with you regarding the symptoms you have seen at home. Next, they will perform bloodwork to determine your pet’s blood glucose and a urinalysis to see if glucose is present in the urine. If diabetes goes undetected for a long time, pets can go into a diabetic crisis called diabetic ketoacidosis. This condition can affect many organs, causing them to appear to be failing, because the body is in a life-threatening state. In the event of such a crisis, some pets would need to be hospitalized in order to reverse this condition and restore proper glucose regulation.
The mainstay of treatment is insulin administration. Again, insulin is the hormone that communicates to the body’s glucose, telling it to move from the bloodstream into the body’s tissues. There are many types of insulin available, and your veterinarian will help determine which is appropriate for your pet, as they can be different for dogs and cats. Insulin should be administered every 12 hours or as directed by your veterinarian.
Diet is another important component. Prescription diets have been formulated to help control hyperglycemia and regulate a pet’s weight while balancing appropriate amounts of fibers, carbohydrates, fats and protein. our veterinarian will help you select which is most palatable and suitable for your pet. In the beginning of diagnosing and treating, your pet will need to be seen at your veterinary hospital frequently for blood glucose curves or fructosamine tests (a protein that helps determine an average of glucose regulation over a couple of weeks) to determine if they are properly regulated. Once regulated, diabetics can remain very stable.
Difficulty regulating a pet can be due to several factors, including improper administration of insulin, not feeding a pet properly, not adhering to a regular schedule, or the presence of a bladder infection or concurrent disease.
It is very important to make sure your pet eats prior to receiving insulin; otherwise, hypoglycemia can occur (too little glucose). Think of a time when you were on the go and hadn’t eaten all day and started getting shaky and weak. This was because your body was deprived of glucose, the energy source you get from foods. Now imagine continuing to stay in that state— it affects not only your body but also your brain, which can result in seizures. The signs of hypoglycemia are important for owners to recognize, because it determines if you should administer insulin or not. And, in severe cases such as seizing, get your pet to a veterinarian immediately.
Monitoring your pet’s urination habits is vital as well. Think about it— glucose is a sugar that’s being spilled into the urine, which is the filtered waste product our kidneys have deter mined our bodies don’t need. This can act as a nidus, a place for bacteria to gather and multiply, which can result in a bladder infection. You never want bladder infections to go undetected and untreated, because they can lead to the formation of bladder stones or the infection can ascend (travel upward) toward your pet’s kidneys and cause them to be affected as well.
Two other main complications seen with diabetes in pets is the development of cataracts and diabetic neuropathy. Diabetic cataracts mainly occur in dogs and will affect the greater majority of diabetic canines. This happens because of the excess sugars that spill into the lens of the eyes, which results in blindness. Oddly, this rarely occurs in cats. However, cats can suffer from diabetic neuropathy like humans do, where the nerve fibers become damaged from the excessive glucose, causing an overall weakness and inability to stand properly.
Diabetes can also be induced in pets that receive excessive steroid shots in veterinary clinics. Steroids are very important for the management of several diseases, but often are a mask or “band-aid” because they give us the desired relief of symptoms that we want for our pets (e.g., stopping itching due to allergies). However, repeated, frequent use of steroids puts pets at risk for developing diabetes because of the effect they have on the pancreas. This is why, when owners request an “allergy shot,” veterinarians often discuss other options and treatments so as to avoid the overuse of steroids.
If you think your pet is at risk for diabetes or showing any of the symptoms discussed, make an appointment with your veterinarian to discuss appropriate diagnostics and treatment options. With proper medication and some education, diabetes is a very manageable disease.