There is concern that animals receiving human insulin will develop antibodies resulting in decreased insulin activity and/or
effectiveness. Dogs receiving any insulin product that is not derived from pork may make antibodies. However, studies have
shown that those antibodies do not interfere with the glucose control. In fact, dogs that made antibodies against insulin
had a longer duration of insulin action, which actually enhanced the effect of the insulin rather than decreased its efficacy.
A recent study in cats should that 13% developed anti-insulin antibodies. None of the cats should signs of insulin resistance.
The options with human insulin include ultra short acting, short acting, intermediate acting, and long-acting insulins. The
short acting insulins are primarily used for ketoacidosis, and therefore, are not covered in this article. The intermediate
acting insulins are classified as either NPH or Lente. It is important to note however, that even though they are classified
as intermediate, they do not behave the same way in the dog or cat. Lente is actually a mixture of semi-lente and ultra lente,
which results in a bimodal onset of actions. This is helpful in some patients because is helps block post- prandial hyperglycemia.
Conversely, a lente insulin is not recommended for use in an animal that does not develop post prandial hyperglycemia. It
is recommended that NPH be used in the majority of dogs and cats with diabetes and it is also understood that most patients
will require two injections a day to achieve glycemic control.
On July 6, Eli Lilly announced that it was discontinuing 4 of its insulin products: Humulin L Lente insulin, Humulin U Ultralente
insulin, Iletin II Regular pork insulin, and Iletin II NPH pork insulin (see attached announcement). Less than 2% of human
patients with diabetes mellitus will be affected by the change since most have been switched to newer insulins and/or insulin
To meet this challenge we will need to switch patients currently taking these products to comparable insulin preparations
and change the way we approach the newly diagnosed dog or cat with diabetes. Therefore, we have put together the following
Newly Diagnosed Patients
1. Vetsulin (porcine origin lente): A zinc, porcine, intermediate acting insulin. Canine and porcine insulin have an identical
amino acid sequence thereby eliminating the theoretical complication of anti-insulin antibodies and their effect on glycemic
control. The suggested, initial starting dose is 0.5 units/kg BID. This insulin is only available at a concentration of 40
iu/ml (U-40) so please make sure that proper insulin syringes are provided to the owner. Re-assessment of clinical signs and
a serial blood glucose curve should be performed 1 week after starting therapy. For additional information see:
2. Humulin N or Novolin N; These are both intermediate acting, human origin insulins. Suggested starting doses are 0.5 units/kg
BID. Re-assessment of clinical signs and a serial blood glucose curve should be performed 1 week after starting therapy.
3. Glargine: To date, no information on the use of glargine in the dog is available (see discussion below regarding glargine
Transitioning Canine Patients
If you have canine patients currently taking Humulin L lente insulin, I would switch them to either Vetsulin or Humulin N.
The initial dose of Vetsulin or Humulin N will remain the same with re-assessment of clinical signs and a serial blood glucose
curve performed 1 week after changing insulin preparations.
Newly Diagnosed Patients
1. Insulin glargine (Lantus): Glargine is a modified, recombinant, long acting insulin analog. A study presented at ACVIM
in 2005 showed a very high rate of remission (8/8 in remission within 4 months with 6/7 still in remission at 1 year) in feline
diabetics with the use of glargine and a low carbohydrate-high protein diet. The recommended starting dose is 0.5 units/kg
BID if the fasting blood sugar is greater than 360 mg/dl and 0.25 units/kg BID if the initial fasting blood glucose is less
than 360 mg/dl. For additional product information see:
http://www.lantus.com/. Glargine highlights: