November is diabetes awareness month. Diabetes is a major problem we see in pets and, yes, it is the same disease as in humans. There are 2 forms of diabetes: type 1, which used to be referred to as juvenile diabetes, and type 2, which used to be considered aged onset diabetes. Both forms result in high blood glucoses (blood sugars) that lead to high blood pressure that causes life threatening damage to the body organs. Type 1 is an acute disease developing in a matter of days with potential lethal implications within days to weeks. Type 2 has a slower onset and may go unnoticed for weeks to months. Today, I will discuss type 1 diabetes.To understand the diseases we first need to discuss the basic pathology.
Insulin is a hormone made by islet cells located in the pancreas. It is responsible for transport of glucose (sugar) into all the cells of the body. Ingestion of a meal causes increased blood glucose levels which stimulate the islet cells to secrete more insulin into the bloodstream. This allows the transport of glucose into the cells where it is involved in cellular maintenance and productivity. Failure of this mechanism results in dramatically increased blood glucose levels, depriving cells of life maintaining nutrition and also causing severe rises in blood pressure further damaging organ cells. Left untreated this damage is fatal.
Type 1 Diabetes
In humans this used to be referred to as juvenile diabetes. I have a personal expertise from raising a son diagnosed at 12 years of age. We see it almost exclusively in dogs.
Type 1 diabetes is an autoimmune disease which means that the dog’s immune system is stimulated to react against and destroy the islet cells in the pancreas. What triggers this reaction is still poorly understood. Some theorize that when the immune system reacts to an infection such as a virus a virtual switch is turned on that make the antibodies react to the islet cells as a foreign substance. Hereditary factors also possibly play a role. Once started this reaction is permanent. The end result is complete destruction of the islet cells and thus no insulin. This is why all type 1 diabetics are insulin dependent, requiring insulin shots daily and frequent blood glucose monitoring.
As stated this is an acute disease meaning the onset is rapid. Initially, the dog develops a ravenous appetite. The blood glucoses increase rapidly and the excess is cleared by the kidneys. The glucose draws water along with it through the kidneys leading to rapid dehydration and a dramatic increase in thirst and urine output. Thus you have a dog that drinks and urinates excessively. If allowed to progress appetite decreases leading to changes in the body that result in a condition referred to as ketoacidosis. The blood becomes acidotic further damaging organs and the lack of nutrition to the brain can lead to a ketoacidotic coma. At this point the disease is potentially fatal.
Some breeds may be over represented but the important fact is any dog can develop the disease. The average age of onset is usually after 4 years of age but can occur at any age.
When presented to us treatments vary according to how far the disease has progressed. If in the early stages, the patient usually can be managed outpatient (at home). If the disease has progressed the dog is usually hospitalized requiring IV fluids , insulin injections, and intense monitoring of the blood glucoses (blood tests). If the dog is critical meds may be needed to control seizures and/or combat kidney failure. Most dogs, if presented in a timely fashion, can be stabilized and will survive with proper home care.
As stated all diabetic dogs are insulin dependent requiring twice a day injections. If the dog is stable and eating well the owner is taught injection techniques and feeding schedules and the dog is sent home. The first several weeks require several visits to our office for glucose monitoring. Once the blood glucose levels are in normal range we usually see them monthly for blood glucose checks and dose changes if needed. Occasionally we will do glucose curves, a type of test that is done over the course of the day, and/or fructosamine levels. Fructosamine levels give us an idea as to how well the patient has done over the last several weeks.
Some owners now do glucose monitoring at home using the same machines as humans use. Insulin pumps are not being used at this time but may be modified for canine use in the future.
We recommend certain diets (Hill’s Prescription Diet w/d) for our diabetic patients. The higher fiber helps control blood sugar levels with a slower and longer absorption of sugar from the gut.
Once stable and if blood parameters indicate no permanent damage to the kidneys or liver the short term prognosis is excellent. Long term prognosis is up to the owner. If they carry out proper monitoring with appropriate insulin dose changes, feed properly, and monitor the weight of the dog, the prognosis is excellent and the dog should live a long, normal life.
The future in humans is exciting. Research is ongoing for a cure and breakthroughs are happening rapidly. This work revolves around stem cell research,and islet cell implants with techniques to protect them from the immune system. Studies are currently being carried on in Europe.
Once these discoveries are complete the technology will hopefully be adapted for use in dogs.
So, to review, the key for successful treatment of diabetic patients is early diagnosis to avoid long term damage and an expensive hospital stay. Once stable your diabetic dog will live a long normal life. However they are totally dependent on their humans for this to happen. Diabetics and their owners have an especially strong bonding that is a very rewarding experience.
This week's blog post written by Dr. Miller.