They need a stool sample to figure out which medicine or medicines he needs. (Different drugs for different bugs.) And they'll need to weigh him to figure out the correct dosage if you've never been there. Once you're in the system, though, you can genrally just pay $20 or so for the stool test, tell them how many grams the snake weighs, and they'll just give you the meds and directions without even having to drag the snake in there. Either way, it'll end up being you, his throat, and a plastic syringe. Not fun, but if you gotta do it you gotta do it. Most likely they'll prescribe either Panacur and/or Flagyl, depending on what they find.
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0.1 Coastal Carpet (Boots)
0.1 Western Hognose (Bebe)
0.1 Cane Toad (Hengo)
0.1 Solomon Islands Ground Skink (Minerva)