by Dr. Elizabeth Ellis
Diabetes (or diabetes mellitus in the medical community) is a very common disease in the United States, both in humans and our companion animal counterparts. Diabetes is a condition in which an individual can’t use the sugar in their bloodstream due to the lack of insulin.
One must understand the basic metabolism of the body to understand diabetes. When a person or animal eats food, the pancreas, which is a small organ near the stomach, releases digestive juices into the intestines to help break down the food for absorption. Once the nutrients are absorbed, glucose (or sugar) increases in the bloodstream. The pancreas secretes hormones into the bloodstream, namely insulin, which allows for the transfer of glucose out of the blood and into individual cells. This glucose is what cells need to function. Without adequate insulin, the glucose in the bloodstream continues to get higher and higher but the cells are essentially starving since they can’t access the glucose. The excess glucose in the bloodstream overwhelms the kidneys and spills into the urine, pulling extra water with it. The starving cells cause the body to break down fat, starch and protein reserves, worsening the high glucose levels in the bloodstream.
There are two types of diabetes mellitus you may have heard of: Type I and Type II. Type I diabetes, also referred to in humans as juvenile onset, is a condition in which the pancreas does not produce any insulin, therefore, the patient requires insulin supplementation for life. Type II, also called adult onset diabetes, occurs when the pancreas produces some insulin but not enough for the body to properly function. Type II diabetics are not necessarily insulin dependent. All dogs have Type I diabetes in which they require insulin; however, cats can have either Type I or II diabetes and some may not require insulin.
In both cats and dogs, the early signs of diabetes mellitus are increased thirst and urination, as well as an increased appetite. Most pets that get diabetes are middle aged, overweight, and tend to eat more treats or human food than they should. Later in the disease stage of diabetes, many pets begin losing weight and ultimately, if not caught, become sick with vomiting, urinary tract infections, and weakness.
Your veterinarian will test your pet for diabetes by checking the blood for dramatically high glucose levels then the urine for high glucose levels. The combination of these findings along with clinical signs of diabetes confirms the diagnosis. If you have an overweight cat that is still feeling well with no signs of advanced disease, your veterinarian may recommend a strict diet to provide for rapid weight loss and more stable blood sugar levels throughout the day. Generally, this diet is high in protein, high in fiber, and low in carbohydrates. Some Type II diabetic cats are able to increase their insulin production and become non-diabetic with just this simple change. Other cats and all dogs will be started on injectable insulin in addition to the diet change.
There are multiple types of insulins available that are used in cats and dogs, and your veterinarian will discuss with you the best type for your specific pet. Most pets require insulin injections under the skin (sub-q) every 12 hours after they have eaten a meal. It is important that your diabetic pet eat the same amount of the same type of food at the same time every day, because the insulin will be dosed according to this and if it varies significantly, your pet will not be able to control the excess or make up for the deficient glucose in his system. Your veterinarian will teach you how to properly mix, store, draw up and administer the insulin. The most common cause of poorly regulated diabetic pets is incorrect storage or administration of insulin, so if you ever have questions as to how you are doing this, please ask your vet.
Many owners are very concerned about injecting their pets with needles twice daily; however, most come to realize that the needle is very small and well tolerated (and sometimes not even noticed) by their pets. Your veterinarian will frequently check your pet’s blood glucose, urinary glucose, and sometimes other tests in order to determine if the insulin dosage is correct until your pet’s glucose becomes well-regulated. Even once well regulated, you can expect your pet to experience periods in which the blood glucose may become too high or too low, causing either signs of diabetes (excessive thirst or urination, ravenous or lack of appetite, weight loss) or signs of low blood glucose (disorientation, weakness, or even seizures). Signs of low blood sugar should immediately be treated by getting your pet to eat, and if they won’t, by feeding enercal from your vet or karo syrup by mouth or rubbed on the gums to quickly raise the blood glucose levels. You will need to be watchful for these signs of improper regulation and take your pet straight to the vet when noticed. Your veterinarian will adjust your pet’s insulin dose based on clinical signs and lab tests, but be sure never to do this on your own!
One of the common complications of diabetes in dogs is cataract formation. The excess glucose in the body is absorbed by the lens of the eye and leads to cataracts, causing blindness. Another common complication is urinary tract infections. Due to the high level of glucose in the urine, bacteria are more apt to survive and multiply in the bladder. Antibiotics are needed to clear these infections. Some other potential diabetic complications are bacterial infections that spread from the teeth to the heart and kidneys, again more common because the glucose in the blood provides a great home for bacteria. Because of this, regular dental cleanings and home dental care are essential in diabetic patients.
Don’t let diabetes in your pet scare you. The combination of diet, exercise, insulin, and careful monitoring with your veterinarian can lead to a long and healthy life in spite of diabetes.
Dr. Elizabeth Ellis DVM appears courtesy of Aspen Ridge Animal Hospital in Lakeside. For more information about this health topic or others, please call (928) 537-5000.