Well any kind of pet can transmit a disease, you just have to know the proper way to care for and clean them and yourself. A lot of the parasites and diseases that live in snails have to be injested to cause harm, so as long as you're not eating them raw right from the garden or not cleaning your hands after handling a snail, you'd probably be ok.
and I don't really want one, it was a joke ;) I just think they're cute
the disease factor is played up to scare people I think. all pets can carry disease, you just wash your hands with soap after handling them. these huge guys are illegal in the US because of the danger to crops. obviously. we keep 2 smaller snails as pets and they seem to enjoy being held. very friendly. who would have guessed.
Oh yeah. Do they bark and wag their tails or something?
Give them a salt bath.
and I don't really want one, it was a joke ;) I just think they're cute