Diabetes Mellitus is a disease by which the islet cells of the pancreas (cells responsible for secreting the hormone insulin into systemic curculation) lack the ability to secrete adequate amounts of insulin, or, insulin receptors on bpdy cells are refractory to the effects of insulin when secreted, or both. Insulin plays an important role in the body regulating blood sugar in response to ingestion of carbohydrates. When blood sugar levels spike in the blood following a carbohydrate rich meal, insulin is secreted by the pancreas to trigger the body cells to take up the excess blood sugar out of systemic circulation. When insulin is deficient from defective pancreatic islet cells, or, if body cell receptors are refractory to the effects of insulin, the result is chronically high blood sugar.
The effects of this disease are two fold. First, since body cells are not effectively taking up sugar, they are depleted of sugar and starved for energy. Second, the excess blood sugar causes physiological problems. Excess sugar ends up passing through the kidneys and gets urinated out. Sugar attracts water, and therefore pulls excess water out of the body, causing dehydration. When the sugar rich urine collects in the urinary bladder, lower urinary tract infections often occur, because bacteria are attracted to the sugar. At the level of the brain, the excess blood sugar causes death of brain cells and disorientation.
Diabetes Mellitus affects both dogs and cats, but in my experience is significantly more prevalent in cats. The patient commonly has a history of obesity, a known condition that predisposes to diabetes.
Symtoms on presentation in both canine and feline species include: excessive drinking and urination, ravenous appetite, weight loss despite adequate or excessive eating, chronic recurring urinary infections, stumbling and weakness in the rear limbs.
Diagnosis is obtained thorugh blood test and urinalysis. Treatment consists of regular insulin injections and feeding a diet low in simple carbohydrates.. PZI insulin at this time is the most consistent type of insulin for management of diabetes in cats, while dogs respond on a more individual basis to various types of insulin.
When first treating a diabetic dog or cat with insulin, the response to insulin is very individual, with a huge variation in blood sugar from one one patient to the next from a given insulin dose. For this reason it is difficult to impossible to predict the proper insulin dose without doing what is called a blood glucose curve. This is when a conservative dosing of insulin is administered, and the blood glucose levels are measured once every two to three hours. The insulin dose is adjusted according to these readings. A dog or cat wil typically be regulated in this manner within 2 - 4 days.
Following the intitial blood glusoe curve, I typically follow up with a fructosamine level in 3 weeks. This guages the canine/feline body's average response to insulin over a 3 week period. The insulin dose is adjusted accordingly. After this, I typically have the patient come in every 6 months for follow up fructosamine analysis. Also, I have the owners randomly test for sugar in the urine with at home urine strips tests.
