Hi
No I dont have any easy answers becaue there's a wide range of possibilities for the cause of his symptoms. If the problem doesnt go away I am guessing your vet will be needing to do more tests for himt. If they can rule out infection they will want to test for other bladder and kidney problems, including bladder stones. This would will involve taking images of your dog's urinary system. If he hasn't responded to the antibiotics I expect your vet will want to carry out a further work up for him next.
Cathy Wickenden BVet Med MRCVS
Barton Lodge Veterinary Centre
1 Midland Road, Hemel Hempstead, Hertfordshire, HP2 5BH
Tel: 01442 216048 24 hours
[
www.bartonlodgevets.co.uk]