I'd advise you not to use "bit" for "bitten" in conversation either: it's still non-standard English.It is common to use "bit" as the past participle of "bite" in conversation, but you should not use it in formal writing.
That sounds like a causative to me:'I had my arm bitten by a dog'
Well... depending upon the context, it could be.Yeah, it is a causative have
Yes, it is, but for whatever reason, that example doesn't sound natural.but it is also used for bad experiences, isn't it?