Cortisone increasing bllod sugar levels in cat

Question
Hi Jessica

About a month ago my 9 year old cat received a cortisone shot for some skin issues had devolped. After that he gardualy started drinking water excessively and urinating in strange places with loss of weight and eating habits changed. After a visit to the vet I was told he now has diabetes and needs insulin injections to start twice a day. Is it possible that this isnt diabetes but elevated due to the shot?

Answer
Hi Tonya.  It is possible for cortisone to cause higher than normal blood sugar and sort of a pre-diabetic state.  In this case, the pancreas would continue to produce a normal amount of insulin, but cortisone causes cells to become insulin resistant.  Insulin is what carries glucose into cells.  So those cells are unable to receive glucose, and the glucose remains in the blood, producing a high blood glucose reading.  Generally, though, when a cat's blood sugar is high enough to warrant insulin, it's true diabetes.

However, sometimes cortisone causes cases of transient diabetes.  The cat will need to be on insulin short-term, but the diabetes is corrected in a matter of a couple of months.  The insulin can be discontinued once the body begins to produce its own cortisol again (the body slacks on this when it receives a cortisone injection).  So you should have her blood sugar monitored carefully to make sure it doesn't dip too low on her insulin.

To further complicate things, though, many times a cortisone injection may just push a cat who was predisposed to diabetes over the edge or unveil a case of mild diabetes that was already present.  The condition is extremely common in cats, and I even have three diabetic cats myself.  So it's difficult to say which of these situations is true.  Overall, cortisone has far more benefits than side effects in cats, but now given your cat's history, it will have to be avoided.

Best of luck!

Jessica