Insulin Administration for Cats

Insulin 101
- written by R. Jung, 2004, but with significant contributions from Kimber & Bunny. To see Kimber's document, you can look at this post on the FDMB health forum or you can go to Gorbzilla.com . Thanks, Kimber!

1. KNOW THE TYPE OF INSULIN & HAVE THE RIGHT SYRINGE. All human insulins (Humulin and others) in the United States are a concentration called U-100. PZI is often U-40. The syringe must match the concentration of the insulin. To be sure you get the right syringe, take your insulin (or the insulin box) into your pharmacist when you go to buy syringes and the pharmacist will make sure you get the right syringes. When you buy the next batch of syringes, take the syringe packaging with you to make sure you buy the right type. If you must use the wrong syringe, use our conversion chart.

2. FOOD. Always make sure your cat eats around the time (up to one hour before injection) of the insulin administration. This will insure that the cat has food in her stomach (and rising blood glucose levels as a result) to counteract the fast action of Humulin N. If your cat is having trouble with vomiting, be very careful and watch for possible hypoglycemic episodes.

3. DO A CURVE & HOME-TEST. This is highly recommended with all insulin use and can be done at home or at the veterinarian's office. FelineDiabetes.com highly recommends home-testing for the best care of your cat, with periodic tests by your vet, including some of the "long-term control" tests such as fructosamine and hemoglobin A1c. Home-testing will greatly assist you in regulating your cat and dramatically decrease the chance of a hypoglycemic episode. It is important to know when the insulin peaks (causes the lowest, or nadir, blood glucose reading) because the time of the nadir varies from cat to cat and also depends on such things as associated illnesses, food intake and exercise. General guidelines for insulin peaks and nadirs in humans are available on many manufacturers' web sites (see references, below).

Knowing the peak action time of the insulin is very important because you do not want your cat to have a hypoglycemic episode that is potentially fatal. Also, you cannot adjust a dosage on a preinjection glucose level alone. Even if the blood glucose level is high before the injection is given, the level can still drop to hypoglycemic levels after injection. Consistently high pre-injection glucose levels can also mean a rebound affect from the insulin causing dangerously low nadirs. If you don't know the nadir level of glucose, you may be tempted to increase the insulin dosage based on the pre-injection levels. This would be incorrect because then the nadir level would go even lower. Do not adjust insulin dosages without your veterinarian's approval and without knowing ALL the data.

To construct a blood glucose curve, check and record the glucose levels at the following times:

One hour prior to injection. Next, one hour after injection and then every one hour after that the numbers have reached a low point and are starting to increase again. You can then do a check two hours later and stop when the numbers are consistently rising. If you are using a long-acting insulin such as L (lente) or Lantis, you may want to check every 2 hours after injection.

4. MAKE CHANGES CAUTIOUSLY. Although short-term reactions to insulin are quick, it still takes about two weeks for the cat's body to fully adjust to a new insulin dose. This can be complicated by changes in diet, exercise, and any associated illnesses. Reducing carbohydrates in the diet is a POTENT factor in reducing blood sugars, and it should not be done without also reducing insulin, and careful monitoring. Go slow (unless you obviously need to DECREASE a dose to prevent a hypoglycemic episode) and make one change in your cat's routine at a time.

5. PAY ATTENTION TO YOUR CAT. Numbers are great, theoretically. Just because your cat's blood glucose levels are in a "normal range," he may still be symptomatic. Note the cat's gait, the water intake and amount of urination, the weight. Your cat may need glucose levels that are higher (or even lower) than "ideal." Work with your vet and make sure you get at least annual exams that include a full blood workup.

6. GET REGULAR CHECKUPS FROM YOUR VET. Current recommendations from the Association of Feline Practitioners is to get a fructosamine or A1c test every 6 months if regulated, every 3 months if not regulated. Again, you and your vet will best determine the frequency of your cat's visits to the vet. Diabetes affects many organs, so function of the kidneys, liver, heart, etc. must be done periodically, at least once per year. Your cat can get other diseases besides diabetes and regular checkups can help in early diagnosis for optimum treatment. Home tests are becoming available for fructosamine and A1c but you still need to go to your vet for a full blood workup once a year.

7. SUGAR. You need to keep a source of simple sugars (glucose, fructose, dextrose, etc.) on hand in the case of an apparent hypoglycemic reaction. Karo syrup, honey, and molasses are cheap and available. If you suspect a hypoglycemic reaction, immediately rub the syrup on the gums or inside of the cheek. If the cat is unconscious or having seizures, be very careful not to give too much at once as this can cause choking and aspiration. In this case, you must be cautious in administration and get to an emergency vet immediately.

Don't worry about your cat's glucose going to high in this event. Hyperglycemia will not kill immediately and short-term hyperglycemia is unlikely to have any adverse affects. Conversely, hypoglycemia can kill and kill quickly. Forget the mess, forget checking blood sugar levels. Rub a sugar syrup on the gums, and repeat even if you are on your way to the ER.

8. SEMI-MOIST FOOD/TREATS. Get to know the "glycemic index" or sugar content of food and treats. Many semi-moist foods and also milk can cause big spikes in blood glucose levels. You will want to avoid these foods and treats during the regulation period and use them sparingly afterward. 8. KNOW YOUR CAT. There may come a time when kitty does not want to eat what s/he is supposed to. It is important to know what foods you can give to entice eating, as it is crucial for the cat to eat while on insulin! Also, if you are curving and kitty's numbers start dropping too low before and/or during peak, it is lifesaving to know what to give in order to start increasing numbers. Things that have worked for myself and others: vanilla ice cream, gravy, white bread, Catsip, donuts, popcorn, dry cat food or dry cat food with tuna water dumped on it, semi-moist cat treats. You will want to know beforehand what high carb foods your cat loves, and will readily eat, so that should you find yourself in a situation where your kitty's numbers are going too low, you already have a supply on hand, and won't waste precious moments experimenting with different foods.

9. "START LOW GO SLOW". This is a popular saying on the Feline Diabetes Message Board. Of course, you want to get your cat regulated quickly (especially for your sake!!) but if you start too high, you greatly increase the risk of hypoglycemia and also prolong the time it will take to get your cat regulated. Many people have found that ½ a unit BID or 1 unit BID ends up being the perfect dosage to keep kitty in the 100-300 range. If your cat requires high dosages of insulin, she needs to be checked for other illnesses and have her diet evaluated. The Cornell University Feline Health Center defines excessively high insulin doses are those greater than one to two units of insulin per pound per day. Felines who use more insulin than this should be evaluated more intensively. Other diseases may be underlying or complicating the diabetes mellitus and as a result, necessitate high insulin dosages. Problems with insulin injection, poor absorption or too rapid metabolism of insulin, or even insulin overdose are potential causes of an apparently excessive insulin requirement.

10. GET SUPPORT. The best place for almost immediate support for your pet's health is the Feline Diabetes Message Board. Often, you will get immediate replies to your questions. Develop a good relationship with your veterinarian and make sure you know where to take your cat for emergency treatment. Find neighbors, older school kids, relatives, and pet sitters who will learn about feline diabetes and give insulin injections. A lot of people may be reluctant at first, but I've always found plenty of back-up support.

Don't get discouraged! Thousands of us take care of cats with diabetes. You can, too.

REFERENCES:

American Association of Feline Practitioners, http://www.aafponline.org

Cornell Feline Health Center, http://www.vet.cornell.edu/Public/FHC/diabetes.html

Feline Diabetes Dictionary, 2004, http://www.felinediabetes.com/dictionary/index.html

Feline Diabetes Education, http://www.felinediabetes.com/faq.htm

Feline Diabetes Message Board, http://www.felinediabetes.com/terms.htm

Glycemic Index, Rick Mendosa, http://diabetes.about.com/library/mendosagi/nmendosagi.htm

Human Insulin Time Activity Profiles, http://www.lillydiabetes.com/Products/TimeActivityProfiles.cfm

©2004
Updated January 2004