Well, I am in Rhode Island and I have been a pet sitter/dog walker for over 11 years. I know of at least two sitters who also offer chicken/farm sitting services. Not EXCLUSIVELY chickens, but in addition to dogs, cats, horses, water fowl, pigs, goats, reptiles. I have recently added chickens to my list of services too. No takers so far, but I still haven't advertised this addition either.
I think its a great little niche market if they only want to deal with chickens and not the customary cat/dog care. I hope they have STRICT biosecurity standards. With cats and dogs we just need to wash our hands thoroughly, insist upon flea prevention/vaccines for all pets and I will also wear my rain boots into homes with multiple pets and spray with bleach solution on my boots before entering and after exiting the house.