I'm going thru a similar issue with my Muddy. When his pain first started, he wasn't blocked but had an inflamation in his bladder. No infection, no crystals, no stones, just an inflamation. We had x-rays, ultrasound, blood work and urinalysis done on him with no explanation. It took a biopsy of his bladder to diagnose him. He has idiopathic cystitus. Idiopathic means "of unknown origin". The issue with idiopathic diseases, and a number of bladder issues are idiopathic in nature, is that if you don't know what causes them, your treatments become hit or miss.
Antibiotics will serve as a temporary anti-inflamatory for his bladder but chances are, if what he has is chronic, it will come back in about 2-4 weeks. If you don't get an exact diagnose of what is going on with your cat, then the vet will not really know how to treat it. And if it turns out to be idiopathic, then you need to educate yourself on the right nutrician and medications you can give to him.
Right now Muddy has been switched to all wet food, low grain and no fish flavors. I have 3 water fountains to encourage him to drink a lot of fluids. Because his urine acidity is high, he's on medication to lower the PH. The cost to diagnose him was high but the ongoing care isn't that costly. I also joined a Yahoo group that deals with urinary type problems that has been a help. Send me a private message if you want the name of that group.
I was so frightened for you guys when I read he was bleeding, and now I'm so thrilled to hear he's going to be okay!!!!!! that he feels better quickly and permanently!
I have a Cat with the same problem. The Ultrasound shows a thick bladder. I hope your Cat feels better. My Cat also had strovite stones 2 years ago. I hope you do not have to start dealing with a cat with bladder problems.
Inflammation makes sense. I hope the vet showed you how to add pressure so that you can make him go at home. It is good he drinks water so he can flush the bacteria out.
I am glad he is going to be okay. You love him very much and he is lucky to have you.
Even just a few days later Oscar is doing very well... he doesnt seem to be in any pain at all anymore.. unfortunatley he is peeing everywhere, but that is a result of the valume... according to the vet, he can only pee when he is relaxed.. and well he's relaxed the most when he is laying down... so we've started putting towels everywhere because he can't control it yet... even just this morning I woke up to the foot of my bed being covered in pee... that was kind of gross, but to be expected I guess
Sign of true love - when peeing in the wrong place is gladly welcomed if it's a sign of returning health!
If he does have litter box aversion issues as he gets better (may have, since he might associate the box with pain), I wonder if you might try to get some new boxes, in slightly different places, and maybe try Cat Attract litter. I have a boy who didn't always use the box - I swear Cat Attract worked like a charm. It's got herbs or something in it that are very 'attractive' to cats.