With advancements in preventative care, wellness visits, and more nutritional diets our pets are living longer than ever. Along with age comes more medical issues. One of those more common endocrinology disease processes that we see affecting cats is diabetes mellitus (DM).
Classic signs of DM include weight loss, an increase in water consumption, and increase in urine output. An owner will commonly notice that the cat seems to be “flooding the litter box with urine”. Some times these signs are quite rapid but often times it is a gradual progression. As we all know cats are very good at hiding their symptoms or signs of illness.
DM is a disease where one of the types of cells in the pancreas does not appropriately produce insulin. Insulin is what is used to drive glucose into the cells from the blood stream. After a cat eats the pancreas should respond by putting out more insulin to help regulate the rise in blood glucose levels. In diabetic patients this does not happen causing the glucose levels to remain elevated. Once the levels reach a certain level the kidney is not able to filter out the glucose and it becomes present in the urine as well. This can lead to urinary tract infections as certain species of bacteria thrive in a high sugar environment. Cats can also develop a neuropathy in the back legs as a complication of DM. This causes them to walk low on their legs as if they are weak in the legs. Unlike dogs we do not worry about diabetic cataracts becoming and issue and unlike people there are no reports of ulcerations on the skin from DM.
Diagnosing DM involves blood tests and a urinalysis performed by your veterinarian. Stress can influence a glucose level so it is not always straight forward in making the diagnosis of DM in a cat. However, once persistent glucose is found in the urine and the glucose level in the bloodstream is elevated (along with the appropriate clinical signs) a diagnosis can be made. After your veterinarian performs appropriate testing to determine the extent of disease and if there are any additional complicating factors they will discuss treatment options. The mainstay in treatment is related to dietary changes. A high protein and carbohydrate restricted diet is very important. There are several veterinary formulas available that come in both a canned and dry formula. The canned formula tends to be lower in carbohydrates but you and your veterinarian will decide which is best for your cat. Some cats can respond to diet alone but insulin injections are often required. This involves using a very small needle (most cats do not even notice) to inject insulin under the skin once or twice daily. Training your cat to tolerate these injections tends to be very easy. Close monitoring of glucose levels will be performed by your veterinarian to determine dose adjustments and again in some cases cats will not have a long term need for insulin. There are different tests used to determine regulation and your veterinarian will determine which test is best for you and your cat.
Once insulin therapy is initiated your veterinarian will closely guide you as to how to monitor your cat as there may be the need for insulin doses to be adjusted. With time the dose may need to be increased or decreased. While this disease can be well managed for several years it can also be a challenge. If the blood glucose level rises too high the body may start to produce ketones which are a toxin to the bloodstream. This is referred to as diabetic ketoacidosis and is considered a medical emergency. If the blood glucose level drops too low seizures can develop which is also a medical emergency. Again, your veterinarian will discuss in great detail with you what signs to look out for that may indicate one of the above being a problem.