Phil P. wrote:

I just re-read your first post and realized I overlooked that he's been
eating s/d! duh. His urine shouldn't have been alkaline 7 hours after
eating s/d.

Does he get very stressed out by trips to the vet? If so, you might want to
check his urine pH at home- or at least collect the sample at home and run
it over to your vet to check. Cats that are very stressed-out can develop
stress-induced respiratory alkalosis that can certainly alkalinize his
urine.

Levi is a very easily stressed kitty, and that visit was particularly
hard for him for a variety of reasons.

The vet and I believe the whole reason Levi got crystals was because of
the stress of a home remodel. He hid in the basement and barely ate and
drank for 3 weeks when I had my floors replaced... having FHV doesn't
help, I'm amazed he didn't get sicker.

I will mention this to our vet and I will also test his urine pH at
home. The results were perplexing because at the last visit his pH was
lower than normal... (and he had both types of crystals).

Thanks again, Phil.