With kids, that really just don’t feel good for any reason, I usually just start them on SQ fluids because they seem to get dehydrated a lot faster then adults when they are sick and not drinking like they should.
I can only get nuflor so they are all treated with that, with pneumonia more often then not I save them although I did have a few years ago that ended up with scaring in the lungs and had a lingering cough but never bothered them. They were adult does
Draxxin is a good choice since its 2 shots, 7 days apart, and hits the lungs directly, which makes it a good first place to start to protect the lungs, it is pricey though..however per my vet and experience, you may need another antibiotic between those two shots if there is still fever 24 hours after first Draxxin shot. I use Nuflor for both adult and kids. I have had good results for both.