my 10 year old Abyssinian doesnt eat when I administer insulin. Ive dropped him down to one unit per day and he is barely eating. He had a great appetite prior to starting insulin. His only symptoms prior to starting insulin were increased water consumption and urinating large amount. Now he is not himself, not eating, lethargic and behavior has dramatically changed. He sleep entire day/night. Might there be another reason why glucose is high? I don't want to give him insulin if he will not eat while on insulin. Please - anyone answer... is this common?