Pabs&Ro
Member
Could you catch a urine sample? Vet can dipstick it for various things (not all of which are accurate) but some things are indicative. The sample needs to be fresh. So when you catch it put it in the fridge and out of the light. Might be worth the vet checking for blood and if cloudy perhaps get a culture? It seems odd that he is not responding to the increase in the dose (but an increase dose take 5 to 7 days to have in impact).