Goliath- My WW Oscar has urine that smells very sweet (almost like popcorn) which a few members have agreed with me about. You should only be worried if he has increased thirst and urine production. If this happens you can often pick up a single Diabetes Test Stick from your vet.
Marica- Diabetes is very rare in Syrians (so I've heard) and smelly urine is common. If you spot clean daily it should keep the smell to a minimum.