DIABETES IN DOGS
THE PROBLEM AND CAUSES
Insulin is a hormone that is produced in the pancreas; it is responsible for regulating blood sugar. Without enough insulin blood sugar levels become abnormally high. This medical problem is diabetes. In dogs, the cause of diabetes is almost always insufficient insulin production by the pancreas.
For any individual dog there almost certainly are multiple causes occuring simultaneously that lead to diabetes. Among the possible causes are:
genetics - certain breeds are predisposed
infection - urinary tract infections and periodontal disease in particular predispose to diabetes
drugs - corticosteroids and other drugs can predispose to diabetes
obesity - possibly the greatest risk factor and complicating factor for diabetes
pancreatitis - inflammation in the pancreas can lead to decreased insulin production
immune-mediated disease - various diseases resulting from severe over-activity of a patient's immune system
SIGNS AND DIAGNOSIS
Most dogs are between 7 and 9 years old when diabetes is diagnosed. The most common signs are increased thirst and urination, increased appetite, and weight loss.
We diagnose diabetes by the patient's history and physical exam, and documenting simultaneous high blood and urine glucose (sugar). Once the diagnosis is made we must then thoroughly screen the patient for co-existing and complicating illness. The tests we usually perform in order to do this include:
blood tests - a general blood profile and pancreatic testing
urine tests - a general urine profile and bacterial culture for urinary tract infection
abdominal x-rays and ultrasound - to screen for liver, pancreatic and urinary tract diseases in particular
other tests may be indicated based on the health status of the individual patient
Treatment of diabetes in dogs requires daily insulin injections; oral and/or dietary therapy do not work. We begin with twice daily insulin injections.
Our first step is to hospitalize the patient for 1 to 2 days. During this time we begin the insulin injections and complete the diagnostic testing outlined above. At the time we discharge your pet to you we dispense the insulin and syringes and demonstrate the handling of the insulin and the injection techinique.
We then re-evaluate the patient once every week or two until an effective and safe insulin dose is found; this usually takes one to two months. At the time of each re-evaluation your dog is hospitalized for the day, we repeat a thorough physical exam, and run a blood glucose curve, which is comprised of a blood glucose test once every 2 hours, beginning between 8 and 9 am and ending between 5 and 6 pm.
Once an apparently effective insulin dose is found we re-evaluate the patient in one month, then once every three to six months. These re-evaluations usually consist of a discussion of how our patient is doing, a physical exam, and a fructosamine blood test. This single blood test gives us a good idea how well your dog's diabetes has been regulated for the preceding 2 to 3 weeks.
EXPECTATIONS AND PROGNOSIS
Initial diagnostic tests and the 1-to-2 month long protocol to establish the correct insulin dose can reach $1000 or more. Well-regulated diabetic dogs usually cost between $1-2 per day for insulin and syringes and approximately $150 for each re-evaluation every 3 to 6 months.
Some owners are familiar with the devastating complications that people with diabetes can suffer, including kidney failure and heart and blood vessel diseases. These are problems that require 10 to 20 years or longer to occur, so we do not see them in dogs.
Some complications that do occur occasionally in dogs are:
cataracts - very common, not reversible; can be removed surgically
lens-induced uveitis - inflammation in the front of the eye due to leakage of protein from the lens
nephropathy - kidney disease
neuropathy - nervous system disease
hypertension - high blood pressure
The average survival time in diabetic dogs is 3 years from the time of diagnosis.
The highest mortality rate is in the first 6 months. Survival through this time period depends largely on identification and management of the previously mentioned complicating factors. Dogs that survive the first six months often maintain a good quality of life for 5 years or more