male cat high ph urine

[tigersmine]

We have a male cat neutered with high ph in his urine. There are crystals forming and blocking him from urinating, he was in the vets office for 4 days because he was blocked, after that we tried special food from the vets office and bite-sized chewy treats for UT problems but he won't eat it. Is there anything else we can do for him, he is only 3 yrs old. Please Help.