He stopped eating over the weekend. I took him to the vet this morning, and his weight had dropped from 12 pounds at his exam last December to 7 1/2 pounds. The doctor found nothing remarkable on examination, except that he was a little dehydrated. They gave him sub-Q fluids and took a blood sample. The vet said they should have the results of the blood tests tomorrow.
I've been feeding the cats Purina's Healthy Weight formula because the girls need to drop pounds, but I've been giving Gabie extra because I wanted him to maintain his weight, not lose any. I may have to give him something different from the food the girls eat. I'm going to get some canned food and offer him some tonight (the girls will have to get a little, too, of course). The vet suggested that I mix beef baby food into his cat food.