Great Dane has trouble breathing when laying down

We have a great dane who is about 7 and a half. One day he went down the stairs outside, fell and couldn't get up. Since then he hasn't been able to stand up under his own power. We took him to the vet yesterday and and he was diagnosed with lymes and anaplasmosis.

They gave him a little over 2 bags of saline, and an injection of Ketoprofen. That night he threw up constantly, and even had a few seizures. My guess was a reaction to the pain meds.

Today he is doing significantly better than yesterday, but still worse than before. He has ragged breathing, almost like he has bile in the back of his throat and needs to cough, a runny nose, and he can't lay down fully without struggling to breathe.

Is this something that needs immediate attention from the vet? When he's still laying upright on his elbows he can breathe, if a little labored. He hasn't really been eating too much and amytime we tried to give him a hotdog or something he's sniffed it and turned the other way. Is there anything I can do to help him over the weekend when the local vets aren't open? Any advice at all would be of tremendous help.