General care for diabetic cats
- recommendations by Lynette Ackman

These are my general recommendations regarding the care of diabetic cats. The recommendations are based on my personal experience (two diabetic cats, currently off insulin) and assisting other people with diabetic cats – both locally and online through various online support groups.

* Feed a low-carbohydrate diet (such as a grainless canned food). This decreases the need for insulin (and in some cases eliminates the need completely). I can't stress this enough. I've seen many cats go off of insulin when fed a low-carb diet only. Elimination of dry food is key. Studies show 60% to 80% of cats no longer need insulin on an appropriate low-carbohydrate diet. Purina DM and other prescription diets like m/d are okay, but not necessary. There are many of low-carbohydrate options available. In fact some are lower in carbohydrates than these prescription diets, as they’re free of grains. See felinediabetes.com for a full analysis of many commercial foods.

I recommend either feeding two times daily - before insulin administration - or if an additional meal is fed, that it be 2-4 hours post-injection (not more than 6 hours post-injection) – so that it is prior to “peak” (the time at which blood glucose is lowest). I fed my cats twice daily, or if concerned left them a low-carb snack (such as some canned food, or freeze-dried treats) in a timed feeder.

* Insulin injections twice daily. My insulin of choice is PZI-Vet. If it is unavailable, is cost-prohibitive, or doesn’t produce desired results, consider BCP-Vet, Lantus, or Vetsulin. Humulin L and Humulin U have been discontinued. Humulin N rarely produces enough duration for twice-daily shots in cats.

* Test blood glucose (BG) using a human glucometer and blood drawn from the ear using a lancet. Although this equipment may be less accurate than some veterinary tools, the decrease in stress to the cat (which elevates BGs) provides a better picture of BG in normal situations without the stress of restraint and/or a blood draw from a vein. I’ve never had a cat dislike or resist testing in this fashion much. My own cats would come to me to be tested. Even if the test is off 10% to 20%, which is possible at extremely high values, you still know if the cat’s BG’s are too high, too low, or desirable. Keep in mind – the glucometers aren’t any more accurate for humans, but they’re still widely used. Why? Because they can prevent a tragedy!

I recommend testing before EVERY shot. If the BG is high, insulin may be given. If BG is low, insulin should not be given. (High and low may vary by the cat and the insulin dose.) The cat should eat prior to insulin administration *if* free-fed food is not available, and the cat hasn't eaten recently. I strongly recommend meal feeding rather than free feeding for diabetic cats, to eliminate much uncertainty in determining whether it is appropriate to give insulin.
I also recommend doing spot checks every day or two, varying the time from 2 to 10 hours after injection - to get an idea of when "peak" (the lowest BG reading) occurs and how low it is.

If the diabetes is unregulated (BGs not generally 100-250), a curve should be performed (tests every 2 to 3 hours) about every two weeks - before adjusting the insulin dose. If feeding differs day versus night (e.g., additional meal(s) during day but not at night) we should mimic the less frequent meal schedule during the curve so as to check for a lowest possible peak reading.

* Fructosamine tests - I don't bother with fructosamine tests other than potentially for diagnosis. I feel testing BG's as noted above gives a much better picture of regulation or lack thereof. Fructosamine tests only show an average glucose level. They don't indicate whether the level is changing dramatically throughout the day or remaining level. I’ve seen many cases where fructosamine results were normal, but ordinary BG tests reveal highly undesirable values – too high, too low, or both.

* Use the start-low/go-slow approach to dosage, as detailed at felinediabetes.com. Too many cats are on needlessly high doses of insulin. By starting at a low dose like 1 unit bid, and increasing slowly (preferably in half units no more frequently than every 2 weeks), you eliminate the possibility of overshooting the optimal dose. Cats can often tolerate higher-than-needed doses with either flat or dramatic roller-coaster blood sugar levels, but then one day vomit or eat less and suddenly experience insulin shock.

* Test for ketones. Urine should be tested for ketones. It should always be tested if situations cause concern - that is, if there is an infection, the cat is not eating, BGs are very high, the cat is acting odd, or the cat is prone to ketones. I'd test only on occasion (perhaps monthly) if the cat isn't prone to ketones and there are no other extenuating circumstances.

* Test for infection. Cats with diabetes are more prone to infection. Urinary tract infections, in particular, should be watched for closely. Infection can quickly lead to ketones, which may become deadly if uncaught.

* Test for dental necessity. Cats with diabetes are more prone to dental infection and tartar. They should be evaluated regularly.

* Routine bloodwork. Cats with diabetes, especially unregulated diabetes, are more likely to suffer kidney damage or other issues. Blood work should be performed routinely, I'd suggest quarterly.

* Vitamin B12. Especially, if the cat suffers neuropathy (leg weakness and/or walking on the hocks of its legs) the cat should receive vitamin B12 (cobalamin) supplementation. I prefer either methylcobalamin orally or cyanocobalamin by sub-cutaneous injection.

* Remember Every Cat is Different! What works for one may not work for another!