My 17 yr. old male cat starting showing some strange symptoms recently, and rather suddenly. He stopped going up and down stairs, stopped getting on the furniture, seems to have weakness or lack of coordination in his hind legs, paces, does not meow, purr or groom. We took him to the vet and after an examination the vet felt he had high blood pressure and that he appeared blind. She could not get his eyes to respond to light. She put him on medication and took blood and urine samples. I took him home, and it's clear to me that although he may not be seeing as well as normal, he is not totally blind. The blood and urine analysis were both normal. The same symptoms have continued. He went back to vet for a follow-up and again all blood and urine tests were normal. At home, his pupils will constrict in the sunlight, especially.
I have an appointment next week with a neurologist, but am wondering if anyone can give me a clue as to what's going on.