I can't feed it to one of mine as it boosts her immune system too much and gives her sweet itch type symptoms, she was really, really itchy last year, I have cut out the garlic and this year no itching!!! - so doesn't work for all!!
feed mine garlic but i do cos my boy has airways probs which its suppose to be good for, and the girl gets some cos i'm giving it to him (and she loves it she will eat garlic out of your hand)
I once knew a shetland who escaped from his stable and consumed an entire just opened tub of garlic. His breath stank for days but seemed to make no difference to the flies whatsoever.