My daughter's cat at her grandmother's house 2 hrs away is sick with what sounds to be a upper respiratory infection. Boot's is a 13 yr old female cat tree that is spayed and has her shots. She has runny eyes and nose for a few days. Tractor Supply there told her to use oxytetracycline hlc 10 grams, but did say how much. Everything I've read says this isn't for cats, please help. I'm in school and can't get to her and she isn't able to take her to the vet.