How long do you use Doxycycline for respiratory infection?

[United Nations of Hens]

My Sussex was prescribed Doxycycline for a respiratory infection. The vet was a bit vague on how long to use it for. My research says 3 to 7 days. The infection seems cleared up after 2 days.

 

[Eggcessive]

I would use it for 5 days. And I would use probiotics daily for up to a week to get the intestinal bacteria back to normal.
https://www.interchemie.com/veterinary-medicines/doxysol-oral.html