Urinary issues

I noticed Parker hadn't peed in his litter box for almost 2 days...I started freaking out thinking he had a blockage. I went to investigate and found he had been peeing in the closet in the spare bedroom. It was brownish tinted. Immediately called the vet. She is keeping him overnight. She asked me what I have been feeding him and when I told her she got curious (Its Performatrin from PetValu). I am taking a can in to her so she can see the food. I think he has been peeing in there off and on for a week or so but never really smelled anything until today. I only recently started feeding him that food. 
She felt his tummy and said his bladder was a tiny bit swollen. I am terrified he will keep peeing around the house. The room where he was peeing is about to be re-done with new floors and all, so the smell should be gone. I just don't want him peeing on the new floor. I am sort of hoping its the food and just cutting it out of his diet will stop the problem for good. I feel so bad though if its something *I* did.

I will know tomorrow morning whats going on. My poor Boo. 

Oh no I'm so sorry! Poor poor Parker!

This kind of worried me too, because I bought some Performatrin for the ferals from my local Pet Valu as well (it was on sale). I hope he'll be alright! for Parker and for you!

Lots of vibes and prayers

Jen.

She said the nitrates in his urine are pretty high, so she wanted to check out the food. She said it seems good but suggested I not feed it to him anymore. Not sure what else could make the levels go up like that but this started when I started giving him that food. I am gonna go back to the other stuff I was feeding him.

He is on antibiotics for a week (maybe 2). He peed in his litter box as soon as he came home. I am keeping him confined to my bedroom for a couple days until I am sure he is comfy using it. The bedroom he was peeing in is totally off limits until hes all better and the floor is replaced.