Backing up to an earlier post of yours:
I think that all the 3 doses of metronidazole (aka Flagyl) did was stimulate his appetite & manage to "harass" some of his hookworms into leaving- they're not likely to be gone from Flagyl alone.
The more I think about what this snake has gone thru (all that Fortaz!) I have a hunch that crypto is not at all responsible for his regurgitation, which is goodbut now you have to get him cleaned out from the remaining hookworms, but do it GENTLY so his body can recover since his digestion has been thrashed. He needs some TLC x 100.
![]()
That his appetite came back ("he was a pig") after 3 doses of Flagyl is NORMAL & expected, but it doesn't mean he was rid of hookworms at that time. Think about it- just because he felt hungry didn't mean his stomach was in any shape to receive & digest his food either, so that's why he regurgitated. I'll say it again- antibiotics are not harmless- they're very hard on a snake's body. They kill the "good gut bacteria" needed for digestion & they're also hard on other organs (liver & kidney).
It's no wonder he's been losing weight- he's been sharing his food with worms PLUS regurgitating when he's tried to eat because his stomach needs help.
You might need a different vet's opinion if this one is as unreceptive as you stated. Sorry to say- but only you know if you can really communicate with her on this or not. I wish I had caught this earlier- but when you said your vet found hookworms, I assumed he was being correctly dosed to get rid of them, & that the Flagyl was in addition to that medication -to stimulate his appetite & clear other parasites he was likely to have. What would have helped in this thread is a one-post "time-line" showing his meds & his regurgitations- it's hard for us to keep it straight or to know how long meds were given.