UTI?

[Kat.Bear.Bandit.]

So, around a month ago I was concerned about Bear because he was wheeking a lot and there was yellowish pee in the cage he shared with Bandit. Before I could take him to the vet he stopped wheeking and gained weight back so I assumed it passed. However, he has started the wheeking again. It only happens when he pees, but still pretty frequent. Bear also doesn't pee a lot when he does. He has lost a little bit of weight but it has leveled out again in the past week. He is still eating and drinking a normal amount.
The yellowish pee is definitely from Bandit, I'm not too worried because I've heard it can be from the oxidizing of chemicals in the pee (i think).
Though I know how important it is to take pigs to the vet when signs like this show up, but my parents won't take Bear to the vet unless it can be easily treated by medications. Are these common symptoms (weight loss and wheeking when peeing) of a UTI or other infection?

 

[Piggies&buns]

Please do see a vet.

Pee which has oxidised (which happens when urine hits air) can turn a rusty colour.

Any pain when urinating must be checked out to rule out all bladder issues - UTI, a bladder stone etc