Ferrets are highly susceptible to canine distemper, and may be to feline distemper as well. It is 100% fatal. Ferrets need a yearlydistemper shot that covers both kinds of distemper.
Ferrets are also highly susceptibale to rabies, and need an annual rabies booster shot.
Ferrets are susceptible to several strains of human influenza.
Ferrets can also get heartworm from mosquitoes.
Lacking sweat glands, ferrets can get heat stroke. Never let your ferret experience tempratures above 90 degrees.
Ferrets are also susceptible to other various deseases and health problems. They need to have regular checkups, just like humans do!