Virginia Simpson and Chance

Diabetes in Dogs
by Elizabeth Gigis, DVM, West Chester Veterinary Center

Most dogs have type I, or insulin-dependent diabetes. The beta cells of the pancreas produce insulin.   With type I diabetes, the dog’s pancreas is not producing enough insulin to take sugar into the cells.  Insulin acts like a little ferry, taking sugar from the blood stream into the inside of cells.  If your pet does not have enough insulin, then the sugar stays in the blood stream and cannot be used inside the cell, where it is needed.  This causes the sugar in the blood stream to be very high.  Diabetes can usually be diagnosed easily by drawing a blood sugar level.  Common symptoms of diabetes are lethargy, increased drinking and urinating, and decreased appetite.  Other symptoms can include chronic infections, vomiting or diarrhea. 

Because dogs are mainly type I, or insulin-dependent, they require life-long insulin administration, generally twice per day.  NPH is an insulin type commonly prescribed in dogs.  This insulin is given every 12 hours, but many other insulin types are available.  The insulin dose is started low, and then rechecked at one to two week intervals until the pet’s correct dose is achieved.   This purpose of this is that while your pet can tolerate a slightly higher dose for a short period of time, having a low blood sugar (called hypoglycemia) can be very serious.   Your veterinarian may elect to do blood glucose curves, where blood sugar is rechecked every few hours, to determine the blood sugar throughout the day before adjusting an insulin dose.  A blood glucose curve is important because it will tell you the blood sugar high, low and length of time the insulin is active for in your pet’s body. 

When giving insulin, is it always important to use the correct type of syringe.  U100 and U40 insulin should be used with their corresponding correct syringe.   Because some pets’ insulin requirements may change over time, they can occasionally develop low blood sugar levels.  Regular rechecks with your veterinarian will help prevent this, but almost all dogs insulin requirements will change over time.  Symptoms of low blood sugar are: weakness, disorientation, seizures, or coma and prolonged low blood sugar can be fatal.  If you notice these symptoms, rub Karo syrup (which is high in sugar) on the gums and seek veterinary help immediately. 

Diabetic pets should be fed at 12 hour intervals.  They should be feed a diet high in fiber, with complex carbohydrates, a fixed amount of protein and restricted fat content.  This will promote gradual food absorption and decrease fluctuations in blood sugar after eating.  If your pet does not eat or vomits after eating, you should administer no more than a half dose of insulin and seek veterinary advice. 

The prognosis for diabetes is good, but requires life-long treatment and management.  This is a significant financial and time investment for pet owners.  Diabetes can also be associated with other underlying diseases, such as Cushing’s disease.  Comprehensive blood work is usually performed at the time of diabetes diagnosis to rule out underlying conditions.  Because of the nature of diabetes, frequent infections are common and routinely need to be addressed.  Unfortunately, diabetes also affects the lens of the eye.  Many dogs become blind after being diagnosed with diabetes.  This is an additional challenge for pet owners and their animals.   If your dog is diagnosed with diabetes, it is important to have an in-depth conversation with your veterinarian regarding the costs, side-effects, and long-term prognosis for your pet.  


Elizabeth Gigis, DVM
West Chester Veterinary Center
7330 Liberty Way, West Chester, OH 45069