I'm so sorry to hear that Donovan is still having crystal problems and that the new diet isn't helping him. Does he drink enough water? I know that putting him on a wet food diet will give him more water intake so this may help him in that way.

Since my cat Cirrus is semi-feral, my vet and I decided to have the surgery for his blockage problem. He's also not quite 2 years old yet and this is very young for these kind of problems. He's now on the Hills Presription C/D Diet for the rest of his life and he loves it. I can tell that he's much happier too.

If Donovan continues to have problems, I would highly recommend to have the surgery. The first few weeks are hard on the cat but after that they feel much better. Prayers and positive thoughts are being sent your way. Please take care.