Insulin Injection Sites for Cats

The best places to inject insulin into your cat are:

* On the side of the chest (called the lateral thorax)
* On the flank, which is the fleshy part of a cat's side between the ribs and the leg
* On the side of the belly (lateral abdomen), or the underbelly
* On the scruff (back of the neck)

Absorption of insulin from the abdomen is more rapid than from the flank.

Some veterinarians feel that the scruff is not the best place to inject because this area is prone to the formation of lumps under the skin, and because it is easier for the owner to mistakenly inject into muscle or skin. Any of these would interfere with proper insulin absorption. Other veterinarians feel that the scruff is acceptable as an injection site if the owner uses proper injection technique.

Whichever injection sites you use, the key is to use proper pinch-up technique so that the needle goes into the fat layer below the skin - not into skin or muscle, and not through the pinch and out the other side, which just squirts insulin onto the pet's fur instead of into the pet.

If you are giving fluids to your cat because it has kidney disease, you are probably inserting the IV into the scruff. If you add insulin injections on top of the fluid injections, the cat will develop scarring on the scruff that will make it harder to inject insulin.

It is important to rotate injection sites, because constant use of the same spot will cause scarring, which will affect how well the insulin is absorbed.

Some pet owners like to shave a 2" by 2" square on the cat's flank or side, then pick different injection sites within that square. As a memory aid, think of a clock’s face inside the square. Give the first injection at Noon, the second at 1:00, the third at 2:00, until you have gone completely around the clock face. If you are giving two injections a day, you will not return to "Noon" for 6 days.

How to Inject a Cat with Insulin

Starting Your Cat on Insulin
In cats, insulin therapy is often started with Human insulin injected with a U-100 insulin syringe, twice a day at feeding time. For example, you may feed and inject your cat when you have breakfast and then again at your dinnertime. If these times vary a bit from day to day, that's fine.

Veterinarians usually prefer to start a cat on the low end of the dose range, and adjust upward if necessary.

Once a day insulin injections are generally not recommended, because it is difficult to regulate a cat with only one daily injection. Once a day therapy is only used when an owner is not able to give the cat two injections a day, or when the insulin keeps working in the cat's body for 24 hours.

It is best to inject the cat immediately after the cat has eaten. If the cat only ate some of its food or none at all, you can cut the insulin dose by half. Also, if the cat vomited its meal, only half the dose of insulin should be given. If the cat has a tendency to vomit, wait 15-30 minutes after it eats before you give it the insulin.

You should only stop giving insulin injections if your veterinarian tells you to. If your cat refuses to eat two meals in a row, call the veterinarian for advice.

Initial Blood Glucose Regulation

When the cat first begins insulin therapy, the veterinarian will probably adjust its insulin dose every few weeks, in roughly 1/2 unit to 1-unit increments, until the cat appears to be well regulated. These adjustments are based on the cat’s body weight and clinical signs of diabetes such as thirst and urination, as well as the results of tests performed by your veterinarian.

Consistently high urine glucose along with continued heavy urination and drinking might indicate that the insulin dose may be too small. On the other hand, consistently negative urine glucose readings may mean that your cat is receiving too much insulin. If you think that your cat's insulin dose may need adjustment, call your veterinarian. Do not try to change the cat's insulin dose on your own.

As long as your cat does not have low blood glucose, during the initial regulation phase the veterinarian may prefer to make small, slow changes in the insulin dose. This allows the cat’s body to get used to each new insulin level. You cannot tell if an insulin dose change is working until after one week has passed and the cat's hormones have settled down. Your cat has been diabetic for several months to years; try to be patient and allow the cat to adjust to lowered blood glucose levels.

Insulin Injection Tips
* Spend as much training time as you need with the veterinarian to make sure that you understand how and when to give your cat insulin. For a refresher, look at our photo tutorial: how to inject your cat with insulin.

* It is not necessary or desirable for you to try keeping your cat's blood glucose at "normal" levels of 80-120 mg/dL. This puts your pet at risk of hypoglycemia (very low blood glucose).

* Diabetic cats can experience large day-to-day fluctuations in blood glucose levels, even if their food and insulin are kept constant. This is why it may take several months for the veterinarian to fine-tune your cat's insulin doses.1

* It is best to inject insulin immediately after the cat has eaten. If the cat ate only some of its food, vomited or did not eat at all, your veterinarian may suggest that you decrease the insulin dose by half. Never skip the insulin dose entirely, but follow your veterinarian's advice. If your pet does not eat for two meals in a row, call your veterinarian before injecting insulin.

* If you inject your cat twice a day, try to give the insulin at the same general time each day, such as breakfast and dinner. However, if these times vary occasionally by 30 to 60 minutes, it will probably not matter. Your pet will probably be fine.

* If you are not sure whether an insulin injection should be given, call your veterinarian for advice.

* Cold insulin hurts. Do not take insulin from the refrigerator and inject it immediately into your pet. Let the insulin come to room temperature. This may take around one hour.

* Always praise your cat or give it a treat after injecting it, so that it associates the insulin therapy with a pleasant experience.

* Unopened vials of insulin should be stored in the refrigerator. Write the date of opening on the vial label as a reminder to discard the vial after one month of use.