Agree. Cranberry juice is too acidic for hamsters as well. Even some humans have problems with cranberry juice. What works for humans isn’t always appropriate for hamsters. Probiotic yoghurt also doesn’t contain the correct probiotics for hamsters (I did some research on this) so it wouldn’t do anything and hamsters can’t process dairy foods well so not that good for them. There are some hamster specific probiotics you can get like Benebac or Dr S from rat rations, but I don’t think it would help with a uti - but would do no harm.
So sorry your hamster has this and it is worrying having to wait. I have also had to wait for an appointment with an exotic vet - when you want something ASAP. In my case I saw a general vet straight away and started antibiotics. But still a wait for a proper diagnosis from exotic vet. (He has an eye problem).
I would just keep giving the Metacam until you get to see the vet but your hammy will probably be given baytril (antibiotic) in case it is a UTI to see if it improves. If it doesn’t improve they will then think about what else it could be. It’s usually trial and error with hamsters.
What you can do meanwhile is start preparing for how to give the baytril. It tastes nasty and food often doesn’t disguise the taste and it’s important they get the full dose regularly so an infection doesn’t worsen and become resistant to the antibiotic.
I’m using meaty beef country hunter dog food- after a tip on here. Works every time. Just a tiny pea sized amount with the baytril mixed in. Because if they can take it in food it’s less stressful for a sick hammy than having to be held and have it squirted into their mouths (and some will spit it out again). It works out a bit expensive wasting most of the pouch of dog food (a pouch does 3 days if kept in the fridge). Pets at home sell it though. Others have used runny honey drawn into the syringe after the baytril - which could work if your hamster will lick from a syringe. Our first Syrian wouldn’t- batted the syringe away.
You could try some other meaty cat food or something but if it doesn’t disguise the taste they won’t eat it.
I use a separate tiny plate to put the pea sized amount on (from a dolls house set!) but a jar lid would work too. That way you can see it’s all gone and licked clean
Pets at home has it quite cheap. A box like this costs about £20 on Amazon!
https://www.petsathome.com/shop/en/p...food-6-x-150g#