I have spent hours & hours using various search engines to locate resources online, including anatomy/morphology charts so that I can identify the organs I am seeing, as well as heart rates, etc., to be able to track stress, shock, etc. (I can see the heartbeat with a light through the shell). I have also read numerous academic articles online, then tried to contact the writers. I did find one PhD with specialty in garden snails - he's in Europe - but he said that there just isn't a lot of information because most folks don't care to doctor or treat snails. Cracks and small shell holes seem pretty easy to fix - we've even successfully treated a couple from "roof falls" (which led to habitat re-design). However, I have a larger snail (about the size of a good-size walnut) with a hole in it's shell that is slightly bigger than a 10-year-old's finger; the mantle is about 60% detached from the shell, and I can see the snail's lung through the open hole. So I am reluctant to use the standard, old-fashioned gauze-and-plaster-of-paris "fix" over internal tissues/organs that may be abraded. I am only using sterile water & very dilute tea tree oil, as I cannot find any confirmation regarding what medicines (anti-microbial, analgesic, lubricating, etc.) are safe for snails.
Any suggestions welcome!