Dog serum infused into humans? (spoiler alert)

Boy. I'm a nurse and never heard if injecting dog serum into a human being. I just looked up treatment for Rocky Mtn Spotted Fever at the CDC and it sure isn't serum from any cured animal or human. It's an antibiotic. I'm always learning, so can definitely be wrong, but this sure did perk my brain up when I thought, "He's NOT going to inject dog serum into a human, right?" I was wrong. He did. It's frightening enough when we transfuse humans with matched human blood or other tissues. There can always be a fatal reaction or severe complications we must watch for. So this is bordering sci-fi in my head. I hope no one would ever do this IRL.