Interspecies diseases between other snakes and Balls

[CritterVet]

IBD is definately a concern, but, if a person you're thinking about getting a boa from has been keeping balls for at least over a few months you should be ok (from a risk of IBD ). BPs can't survive long after exposure to IBD, from what i understand its almost a 30 day period but i may be wrong on that.

The other posters are correct as well -- mites, ticks (if wild caught animals are in the mix), any other bacterias or protozoa (especially if your quarantine practices aren't tip top).

The stress of moving to a new home can weaken an animal's immune system allowing a latent virus (or parasite) to become active, and thus infectious. Because of this, I would still quarantine boas (and any reptile) no matter where it came from. In my opinion, there really is nothing to gain from not quarantining.