Cat urine smells off

Hi everyone. I have noticed in the past 2 weeks the smell of one of my cats urine smells a lot like ammonia or something. It is a very strong smell and I have not noticed this before. I have 1 cat that is around 9 and the other 5 are under 3. The youngest one got fixed 2 weeks ago and at first I thought it was because she had surgery, but it has continued. I keep the same routine and I feed them kitten chow and the naturals cat food, i switch back and forth between the two and they all have been on that for a while. I clean out the litter boxes every day. Any ideas? Does it sound normal?? Thanks!

I would call the vet ....

do you know which cat it is??

I have a feeling it is either the old one or the one who just had surgery, but i am not sure. My apartment has also been smelling like cat pee, from the litter boxes and I have NEVER had that problem before either unless it was close to the time I clean them out. Even after I clean them out the smell lingers. I have spray, but this is just different.

Well, I don't know if this is at all the same. But when Kota is working up to a UTI episode, his pee starts smelling more and more...starchy? It's a very odd smell and it's very hard to clear the smell. For the longest time I couldn't figure out where it was coming from. It didn't seem to eminate from the litterbox and it didn't smell much better after I'd cleaned the litterbox. Eventually, I happened to smell Kota and recognized the scent right away.

Could you try smelling the cats?

Yeah I can do that. Thanks for all the help! I called the vet and they said to see if any of them are using the potty more then normal... u know the regulars u watch for when they have a UTI. I just realized it has been 3 weeks and not 2 weeks since Susie got fixed... I forgot to take out her stitches last week... poor little girl I have to take them out now! I got one out but she doesnt like it.