Ivemectrin is also used to prevent heartworms in dogs. It's taken orally, once a month, you probably see it listed as "Heartgard", and it's also a livestock wormer(cattle predominantly).

I would not use ivomectrin injected into any animal without a vet approval. I would not rely on someone 'thinking' they remember that it's bad for some snakes but not thinking that certain pet species were actually listed. I will probably be asking the vet that works next to me about the possibility of using ivomectrin on snakes, just because it has me curious. I've read a lot about ivomectrin myself.. but I wouldn't rely on my memory of it either, lol.

Any snake having a reaction would be enough for me to simply use the PAM spray instead to treat mites, or even just spray all the cages maybe once a year, just to prevent any possible infestation, as opposed to using a injection(or even oral) drug that isn't prescribed on a regular basis for snakes.

I don't know of any vaccinations at all for snakes. A yearly checkup is a nice thing, although not many of the people I know do so. Salmonella is also often present in chicken and most raw meats and also in eggs. Reptiles just get a bad reputation over it. After all, the two most recent outbreaks I can think of were on vegetables, not critters.

My $0.02