Can a s.q. cause congestion in your dog?

A few hours ago my puppy was given Subcutaneous fluid for his dehydration because he is very sick. We have an appointment in the morning for the vet set by the emergency vet but I am worried he may not make it through the night. So i was wondering is this a normal side effect of it because he didn't have any kind of congestion before the s.q.

If by congestion you mean nasal, as in sinus congestion, then no.If you mean congestion like in the lungs, as in hard time breathing, then yes, but it would have to be a large overdose of fluids (very unlikely) or a chronic condition such as heart failure to cause it. If she is having a hard time breathing, you may need to go in tonight. Otherwise, talk to your vet in the AM