All freshly imported venomous snakes and newly acquired long term captives and captive born snakes should be checked for internal and external parasites. We recommend 0.25% to 0.5% permethrin Nix lice bedding spray on cages and bedding for external parasites, and the nontoxic product Reptile Relief to be sprayed on the snake itself.
Internal parasites can be medicated with several different kinds of drugs depending on what species they are - and in some cases on what species the snake is. Panacur and Flagyl (fenbendazole and metronidazole) are relatively safe at 50mg/kg, but Ivermectin has a very a narrow range of safety and known sensitivities in some species such as Crotalus durissus. Anecdotal reports suggest that it can be used safely at 0.02 mg/kg in Bitis and Dendroaspis as a single dose. There are some reports of fatalities when a second dose is administered.
Some keepers "shotgun" snakes with antihelminic medications without doing a fecal exam, but it is always best to pinpoint what parasites the snake has and address them with the proper drugs. You can learn to do your own fecals very easily with an inexpensive microscope.
This freshly imported black mamba is getting a dose of Flagyl for Entamoeba invadens infection identified by fecal wash and direct smear. A stainless steel feeding needle (sold by Midwest) is being used to deliver the drug. Note the air in the syringe of equal volume to the needle so that all of the drug is actually pushed through. A longer red rubber cathether would be used if a larger volume of fluids was being given to a dehydrated animal, with the drug preloaded in front and water in the back to push the drug.
Learn more about the veterinary care of venomous snakes here.