Diabetes in cats
Diabetes mellitus is a disease of the pancreas. This is a small but vital organ located near the stomach. It has two significant populations of cells. One group of cells produces the enzymes necessary for proper digestion. The other group, called beta-cells, produces the hormone called insulin. Diabetes is a failure of the pancreas to produce insulin.
Glucose is a sugar that provides much of the energy needed for life, and it must get into our body cells in order to be used. Insulin is the gatekeeper between the bloodstream and the inside of the body cells. It opens the glucose portals, allowing glucose to leave the blood stream and pass into the cells. Without an adequate amount of insulin, glucose is unable to get into the cells. It accumulates in the blood, unable to go anywhere, and unusable by the cells.
Without insulin, the cells can't get glucose and become starved for a source of energy. In response to this, the body starts breaking down stores of fat and protein to use as alternative energy sources. As a consequence, a diabetic pet eats more; thus, we have weight loss in a cat or dog despite a good appetite. The body tries to eliminate the excess glucose by excreting it in the urine. However, glucose takes water with it, resulting in the production of a large amount of dilute (but sugary) urine. With all the water being wasted in urine, dehydration sets in. To avoid dehydration, the animal drinks more and more water. Thus, we have the four classical signs of diabetes:
Increased water consumption
The diagnosis of diabetes mellitus is based on three criteria: the four classical clinical signs, the presence of a persistently high level of glucose in the blood stream, and the presence of glucose in the urine.
What are the implications for me and my cat?
For the diabetic cat, one reality exists: blood glucose cannot be normalized without treatment. Although the cats can go a couple of days without treatment and not get into a crisis, treatment should be looked upon as part of the cat's daily routine. Treatment always requires some dietary changes and usually administration of insulin. As for you, the owner, there are two implications: financial commitment and personal commitment.
When your cat is well regulated, the maintenance costs are minimal. The special diet, insulin, and syringes are not expensive. However, the financial commitment is significant during the initial regulation process and if complications arise.
Initially, your cat could be hospitalized if there is an immediate crisis. Cats in this state, called ketoacidosis, may require a week or more of hospitalization with quite a bit of laboratory testing. If this is a routine diagnosis (no ketoacidosis) there is no hospitalization required. We will teach you how to give the insulin and your cat goes home for you to administer medication.
Monitoring and initial regulation of the insulin dose is vital. At first, return visits are required every 7-10 days to monitor progress (blood glucose levels). We generally do a "spot check" of the glucose in the afternoon just to see if we are even close to the correct glucose level. It may take 2 months or more before we get reasonable regulation.
The financial commitment may again be significant if complications arise. We will work with you to try and achieve consistent regulation, but a few cats are difficult to keep regulated. It is important that you pay close attention to our instructions related to administration of medication, to diet, and to home monitoring. Another complication that can arise is hypoglycemia, or low blood sugar; if severe, it may be fatal. This may occur due to inconsistencies in treatment. This will be explained in subsequent paragraphs.
Your personal commitment to treating this cat is very important in maintaining regulation and preventing crises. Most diabetic cats require insulin injections twice daily. They must be fed the same food in the same amount every day. If you are out of town for more than a few days, your cat must receive proper treatment while you are gone. On the plus side, most cats can cope with out insulin for a couple of days here and there.
These factors should be considered carefully before deciding to treat a diabetic cat.
Management, not cure?
Diabetes is not at this time a curable disease. With good management, however, your cat can live a long time and have a good quality of life.
The first step in treatment is to alter your cat's diet. Cats are obligate carnivores. Diabetic cats require a food that is high in protein and low in carbohydrates. This may take the form of a prescription food like PVD "Diabetes Management" or Royal Canin/Waltham's "Diabetic DS". Canned diets are lower in carbohydrates and are better than dry diets for diabetic cats. Alternatively, some owners try raw feeding.
Your cat's feeding routine is somewhat flexible. Cats that snack during the day may have better glucose regulation than those that eat meals. However, it is not a good idea to leave canned or raw food out all day!
Non-insulin-dependent diabetes mellitus (NIDDM)
Good news! About 30% of cats with diabetes end up not needing insulin injections. Their blood glucose levels will stabilize with diet change alone. Some cats cycle between being insulin-dependent (needing some level of insulin injection) and maintaining on diet alone. This is something that we can watch and hope for as treatment progresses. With some stable diabetic cats (who show little weight loss or illness) we may try diet change alone and monitor blood glucose levels over a month or two. Most cats, however, need insulin injections at least in the beginning of treatment to normalize their blood sugar levels and stop the illness cycle.
The foundation for regulating blood glucose is the administration of insulin by injection. Many people are initially fearful of giving insulin injections. If this is your initial reaction, consider these points:
- Insulin does not cause pain when it is injected.
- The injections are made with very tiny needles that your cat hardly feels.
- The injections are given just under the skin in areas in which it is almost impossible to cause damage to any vital organ.
Please do not decide whether to treat your cat with insulin until we have demonstrated the injection technique. You will be pleasantly surprised at how easy it is.
We have moved away from trying to gain strict control over the blood glucose levels in most cats. We rely most on a blood test called fructosamine. This is a really neat test that gives us an "average" of the cat's blood sugar levels for the preceding 3 or 4 weeks.