How long can a cat go without a wee??

[WinstonlovesJulia1984]

I have to get a urine sample from my cat. He is shut in a room, as per the vet's instructions, with a litter tray of non-absorbable sand and he is supposed to stay in there till he's done it. There's yowling & scratching at the door and every time I go in to check the litter tray he makes a bid for freedom and tries to get past me. It's been 8 hours now and I'm wondering how long he can hold out?!

He's an outdoor cat and has not used a litter tray since he was a kitten (he's now nearly 6) so I'm worried he won't understand what it's for! The vet said sometimes outdoor cats in these circumstances just do it in the corner of the room....

I wondered if it was urethral obstruction - it’s good that you caught it early. I’m assuming she wants a sample to check for crystals /sediment in his urine. Sometimes the urethral blockage can simply be a spasm (again often stress related) If he’s on prescription food this should hopefully sort crystals out.

Just be careful as dehydration and stress can trigger future episodes - see previous link I sent - these are main triggers for idiopathic cystitis, sometimes it’s actually better just to monitor clinically I.e is he well in himself than create potential problems. It wouldn't be an issue in a normal moggy but if he’s mostly outdoors managing him like a friendly indoor cat might not be appropriate. Hopefully he’s pee’d by now and you Can free him