My hen is really sick. She's underweight, and has a really nasty vent infection plus a limp. At first I thought it was mites/worms so I treated her for that but she didn't get better. Then thought it might be vent gleet with a combo limp. I don't think it is Marek's... but one vet told me via email that is what he thought it was. A nurse friend took a swab of her vent today and found out that it is a bacterial infection with a PH of 6.5 so it can't be vent gleet. At this point I think she's probably a goner but I have some Clindamycin here and I just want to give her something ASAP. Can I give her this?