What is Diabetes?
Diabetes mellitus (DM) literally means “sweet urine”. Diabetes occurs in pets due to a deficiency of, or resistance to, insulin in the body. Insulin, which enables the body to use utilize glucose, is produced by specialized cells in the pancreas called beta cells. Without insulin the body cannot move glucose into cells where it is needed. There are 2 types of diabetes that occur in dogs and cats.
Type 1 (insulin dependent) means the body is not producing any insulin so insulin needs to be administered. Type 2 (non-insulin dependent) is due to a relative deficiency of insulin or an inability of the body to use the insulin that is made (insulin resistance). Type 1 is by far the most common type and the kind that we see almost exclusively in dogs.
What are the signs of Diabetes?
In DM, glucose is unable to get into the cells so the body feels it is starving. Therefore, the patient eats more which raises the blood glucose level still higher. Once that occurs, the glucose level is so high in the blood it is lost in the urine. This makes the patient urinate more and, consequently, drink more. Most owners notice their pet drinking, urinating and eating more while losing weight. There are several factors which may be associated with the development of DM in dogs and cats such as genetics, immune-mediated destruction of beta cells, obesity, infection, pancreatitis and certain drugs. DM may also be seen in conjunction with other diseases such as heat cycles in an intact female dog, Cushing’s disease and growth hormone excess (acromegaly).
How is it detected?
DM is diagnosed by bloodwork and analysis of the urine. Most diabetics are otherwise healthy. Diabetes may be treated with insulin injections given once or twice a day. There are numerous types of insulin and each is used for a specific reason. Based on past experience and the medical condition of your pet, your doctor will select the most appropriate insulin type. Although there are some cases where a dog or cat may recover from diabetes, most pets require insulin for life.
How is Diabetes treated?
The patient is usually started on a low dose of insulin to minimize the risk of hypoglycemia (low blood sugar). It takes the new insulin dose about a week to equilibrate within the body. To ensure that the pet is on the appropriate dose and frequency of insulin, a glucose curve is then performed. This consists of measuring the blood glucose every 2-3 hours for a 12 – 24 hour period. Based on these results as well as how your pet is doing at home, your doctor will adjust the insulin dose as needed. Your veterinarian may make some diet recommendations as well. Your veterinarian will assist you in choosing the right diet for your diabetic pet. It often takes 3-4 months to get a new diabetic patient regulated and may require frequent visits to the vet initially. Once the patient is regulated, your pet may only need to be seen every 3-6 months.
What are the possible complications of DM?
There are several potential complications of DM in pets. Dogs are very prone to developing cataracts which may develop suddenly and will cause blindness. In most cases however, cataract surgery can be done and vision restored. Cats may sometimes develop weakness in the rear limbs (diabetic neuropathy) which mayor may not be reversed once the diabetes is regulated. Diabetic patients are also at a higher risk for developing infections due to a compromised immune system. Any infection can cause dysregulation of their diabetes. One of the common areas where we see infections is in the bladder so your veterinarian may need to culture your pets urine to ensure there are no bacteria present. Some diabetic patients may develop ketoacidotic diabetes mellitus. Some pets maybe diagnosed with DM because they go to see their veterinarian ketoacidotic crisis. These patients may have another disease (i.e. pancreatitis) which may predispose them to developing this problem. Ketones are metabolic products that commonly are present in small amounts in the body but diabetics cannot metabolize them effectively. These ketones accumulate and the patient becomes dehydrated, which can cause vomiting or diarrhea. This condition is life threatening if not recognized and treated aggressively. These patients require intensive care with IV fluids to correct dehydration and electrolyte imbalances. Any concurrent conditions may also need to be treated. Once the ketosis is corrected, the patient is treated as any other diabetic patient.