Perhaps they are referring to IBD. Which can be transmitted by handling. But that's a disease not a toxicity. That's just what came to mind when I read that.

I agree that you probably should do a bit more research before saying things like boas are toxic and anacondas are venomous.

To The op: I have seen this 1000+ times. The best thing to do is to not buy them. I know it's like the hardest thing in the world to do but they will just get another to do the same thing. Perhaps complain and complain and complain some more to anyone That will listen with authority over the store. I pray they change.