Hello Jen, Thanks for oyur message, Bertie is 9 months, In April he lost his sight overnight, which after vet visits and to an opthalmologist he had to have cataracts removed from both eyes, it was before his surgery that he started to twitch, it seemed like a hic-cup, however I mentioned to the eye surgeon and also quite a few times to my own vet, on one visit I saw a vet nurse who was concerned and that led to Bertie been tested first for Diabetes, then for a liver shunt, the first bio acid test showed high, but after a week he had another which was fine, so then I asked for a second opinion, and went to see another vet, who does MRI scanning, Bertie is small for his age, the tremor starts at his eyes twitching and goes throughout his body, he is not eating too well, I have him on Royal Canin mini sensible with a little caesar and he is eating a bit better, but only if hand fed(which I am pleased to do) he doesnt mind a collar on, but will not have a lead attatched and will not walk on a lead, so I have bought a puppia but still not too good. In himself he is lively and plays with my other cav an 7 yrs tri boy called Oliver, also my 3 cats. Hope I have some luck on the forum. regards Joan, Oliver and Bertie(puppy)