When we run a glucose curve, sometimes we may actually drop the insulin dose. Those who have read my newsletters know that I like to sneak up on an insulin dose. I rarely increase the dose by more than half a unit in a small pet, or a full unit in a medium or larger pet at any one dose change. The reason for this is that we don’t want to accidentally by-pass the pet’s current insulin requirement. We know that insulin doses can change over time as we address causes of insulin resistance – such as obesity and infection – and change the way we feed our pets, but that’s another newsletter!
Insulin dosing is dependent on numerous factors. Was there a medication administered, such as a steroid, that caused insulin resistance? If the pet is female, the hormones associated with going into heat can also cause insulin resistance. Infections, such as from dental disease or urinary tract infections, are common causes of insulin resistance. Pets with type 2 diabetes may actually produce extra insulin to combat these causes of insulin resistance. Alternatively, some pets may form some insulin but not enough to control their glucose regulation. Some pets may form no insulin whatsoever. Pets who have had an insult to the pancreas (such as from pancreatitis which means an inflamed pancreas) may gradually lose their ability to make insulin. It’s not an all or nothing deal for many pets. It’s more of a fluid continuum. This is why we periodically run blood glucose curves to see how we are doing.
I’ve had several readers ask about the ‘Somogyi Overswing’ phenomenon this year. Let’s go over it again. If we give too much insulin (whether because we eagerly upped up the dose too quickly or because we are controlling some of the causes of insulin resistance such that the pet needs less insulin), the blood glucose could go too low. If the blood glucose drops into the 60s or so the liver takes matters into its own hands. The liver can utilize pathways to make glucose and this can cause the blood glucose level to shoot up for several hours. Then the pet’s glucose levels are uncontrolled for much of the day and the pet continues to be thirsty, urinate frequently, and just not feel good. This is why I like to sneak upon the insulin dose! The Somogyi Overswing can be difficult to identify.
Lots of diabetic pet owners check their pet’s blood glucose curves each time they give an injection of insulin. Provided that nothing seems amiss, I do not recommend this. Perhaps you have pets that are more tolerant than my own little monsters, but I am a vet who relies primarily on blood glucose curves and do spot checks only if things seem out of the ordinary that day or if I’m hoping for diabetic remission for a type 2 diabetic cat. Tight diabetic control in cats is another topic we’ve already covered.
Even if you choose to perform daily monitoring before injections, you STILL need to run glucose curves periodically. My pet peeve about folks trying to adjust insulin doses based on spot checks (which a method to which a lot of people and even some vets ascribe) is that we might give too much insulin, find a high blood glucose level in the afternoon spot check and make the wrong assumption about the insulin dose. If the pet is experiencing the Somogyi Overswing and we find a high blood glucose level in the afternoon, one might inappropriately increase the insulin dose instead of decreasing it.
Whew! Does this make sense? One of my goals as the staff veterinarian for ADW is to help you understand why we vets do what we do. As the diabetic pet owner, you are on the front line. We want you to make educated choices and understand why we recommend what we recommend and how small changes can improve your diabetic pet’s glucose regulation.
NOTE: Consult your veterinarian first to make sure my recommendations fit your pets special health needs.