I only say this because I have a 19 yo feral that will do that because of bladder stones. I've been giving her apple cider vinegar (ACV) in her food for 5 yrs and she's fine unless I forget for a few days. Found out thru a site called earth clinic that apple cider vinegar will dissolve the stones in cats, IF they will drink it. Being feral, she will eat anything. I put 1/4 cup of water, a dropper full of ACV and a couple tablespoons of canned food and mix it well. She drinks all the 'juice' off it and I throw away what's left.
Just so you know, I had a male years ago that almost died from it, so I knew the symptoms when my feral girl started having trouble. Unfortunately, I had just moved and was flat broke and if I couldn't find an answer, she was going to die. So I spent all night online until I found earthclinic and that info about ACV. I had no clue if it would work, but many people swore by it. It was worth a shot in my mind, I was penniless. It is recommended to use organic ACV, but all I had was plain ole ACV from Heinz. I started dosing her twice a day and in 3 days she had gone from green pea size urine drops to grape size. In 2 weeks she was back to normal urine output and had stopped showing blood. Twice in the last 5 years when things were hectic, I forgot about it for 3-4 days and noticed she was starting to have issues again. Before it got worse, I went back to the ACV and it clears right up. Now I give it 3 times a week and no problems.
I hope the vet can take care of your little one. Some cats repeatedly have a bladder stone issues and it can be expensive. I won't recommend using ACV, I will only tell you what I have done and what the results were. It has worked 100% for my Meow Meow. Thankfully, the other 2 haven't had the issue, since they won't go near ACV. :lol: