I was reading a post today and it made me wonder how people differentiate between a UTI and constipation. Typically when a glider hisses while straining with its tail raised, it's constipation, right? I have not had a glider with a UTI...is there a more distinctive sign that this is the problem rather than constipation? -Or do people just treat it as constipation at first by offering more watery fruits and juice and when it doesn't stop the hissing, make a trip to the vet for him to decide?

i believe hissing could be a sign of either. i think the only way to determine is to have tests done.

Suggies hiss when they strain to potty because it hurts. It can hurt for either reason, however, if the suggie has normal looking poo it is more likely a UTI.

The vet will do lab work and test the urine and feces and be able to get info to help with the diagnosis.

what if underneath their tail is wet?

it really sounds as if your little one needs to see the vet.. no matter what the problem..

if it is constipation, that could be a sign of dehydration, also which only a symptom, of much bigger problems
a UTI left undiagnosed and treated can also cause serious problems.

both of which could lead to self mutilation if left untreated. please see a vet, and have the tests run to see what the problem is.