I am so sorry. It is tough to make the decision.
Talk to the oncologist about which medications will be used. I could easily be wrong about the protocol, but I think it will include prednisone and vincristine. Worst case here would be the prednisone can make the blood sugar go higher, which can be a problem for those with diabetes. Note it doesn't always happen and it can be treated with adjustments in the insulin dosage. You just need to be aware of it as a possibility and be prepared in case it does happen.
Worse case with the vincristine is it can cause some issues with constipation and abdominal cramping, and temporary paralysis of the intestines. This may require some changes in the way you treat the IBD. This doesn't usually occur until several cycles of treatment have been given, if it happens at all.
You want to make an informed decision. Your cat may not have the above side effects, but with diabetes and IBD, these are the things to watch out for during treatment. Be prepared so you know in advance what to do if they occur.
Talk to the oncologist about which medications will be used. I could easily be wrong about the protocol, but I think it will include prednisone and vincristine. Worst case here would be the prednisone can make the blood sugar go higher, which can be a problem for those with diabetes. Note it doesn't always happen and it can be treated with adjustments in the insulin dosage. You just need to be aware of it as a possibility and be prepared in case it does happen.
Worse case with the vincristine is it can cause some issues with constipation and abdominal cramping, and temporary paralysis of the intestines. This may require some changes in the way you treat the IBD. This doesn't usually occur until several cycles of treatment have been given, if it happens at all.
You want to make an informed decision. Your cat may not have the above side effects, but with diabetes and IBD, these are the things to watch out for during treatment. Be prepared so you know in advance what to do if they occur.