My hen has a very large swollen abscess on her leg. It is hot to the touch, so obviously infected. I inherited my chickens just over a week ago, so I am no expert and am very worried and unsure what to do. I have removed her from the other chickens and put her in her own coop and put food and water within her reach (she cannot walk). I am not sure if I should try and give her antibiotics (are these available at a pet store without going to the vet?) or even put her out of her misery. My biggest concern is that she not suffer too much, but I certainly don't want to kill her if I could treat her. This came on very quickly - we noticed she was limping just a few days ago and then when we went out this morning, she was lying on the ground, unable to get up. Thank you for any suggestions.