Q & A: Diabetes in Pets
By Dr. Kim Everson, DVM
Question: My cat has been drinking a ton of water lately. My friend says she probably has diabetes and will need to be put to sleep. I know she’s old, but I really hate to do that because she seems pretty happy. What do you think?
Answer: I’m glad to hear your kitty still is acting happy. Cats hide illness very well and might only give subtle hints that there is something wrong. Hiding, not eating well, vomiting, going to the bathroom outside the litter box or having an increased thirst can signal various illnesses. Any behavior changes like this should be considered an alert that your cat needs a veterinary check-up right away.
One of the most noticeable symptoms of diabetes mellitus in pets is increased drinking with associated increased urination. Examination, bloodwork and urine tests are all required to definitively diagnose diabetes in dogs and cats. The good news is that many pets can live comfortably with management of their diabetes through diet changes and insulin injections, so a diagnosis of diabetes does not have to be a death sentence!
Before we talk a little more about diabetes in pets, I should point out that a noticeable increase in thirst is not just a sign of diabetes. Increased thirst is also seen with kidney and liver diseases, elevated thyroid levels, life-threatening uterine infections in unspayed pets, certain electrolyte imbalances, and a host of other conditions. A thorough history, comprehensive physical examination, various laboratory tests and imaging studies (like x-rays or ultrasound) may be needed to fully understand a pet’s increased thirst.
Diabetes mellitus in pets and people is a complex metabolic disorder involving the body’s inability to utilize sugar (glucose) for energy. If the pancreas cannot produce insulin or the body tissues cannot respond to insulin in order to convert blood sugar into energy, the result is elevated blood glucose levels and (over time) weight loss because the body cannot obtain nutrition from meals eaten. Sustained increased blood sugar has a negative effect on the organs and can lead to cataracts, bladder infections, liver damage, neuromuscular problems and serious electrolyte changes among other problems. In really severe cases, life threatening diabetic ketoacidosis can occur with symptoms including vomiting and diarrhea, dehydration, stupor or coma.
Early diagnosed and properly managed, diabetic dogs and cats can enjoy a prolonged quality of life. The majority of diabetic dogs have Type I or insulin-dependent diabetes mellitus meaning their pancreas cannot produce adequate insulin to get blood glucose into the tissues. Diabetic dogs therefore require daily insulin injections for the rest of their lives. Many cats also develop Type I diabetes and require insulin. A large number of cats, however, develop Type II or non-insulin-dependent diabetes mellitus secondary to obesity and can be managed or even cured with strict dietary management.
Pet owners are usually quite surprised by their ability to give insulin injections at home. The needles are tiny and most pets tolerate the treatment very well. Some pets even seem to understand that the momentary discomfort will help them feel better! Insulin therapy is often started in the veterinary hospital during a 12 to 24 hour “glucose curve” to ensure that the pet does not develop hypoglycemia, or low blood sugar, from too high an insulin dose. Hypoglycemia is dangerous and can cause weakness, stumbling, seizures and coma.
Management of diabetes in veterinary patients is constantly evolving! Nowadays pet owners may even be trained to perform glucose curves at home where the pet is most comfortable. Regardless of whether the pet will be tested in the clinic or at home, good communication is essential between the pet owner and veterinarian. Early management of diabetic pets is sometimes challenging and requires patience and discipline, but the results can be very satisfying for all involved.
Originally printed in Pet Journal, May 2014