My father-in-law has a 2-week old, very sick calf. It's navel got infected about a week ago. The vet came and gave it Nuflor. The calf is getting worse...very weak. My father-in-law tubed it this morning because it had quit eating. Is there a better antibiotic that should be used instead of Nuflor? Any other suggestions about what to do for a bad infection?