Two of my cats have recently had UTIs (crystals). One was on 125mg. of Clavamox twice a day for 10 days, the other 62.5mg. of Clavamox twice a day for 14 days. Different vets at the clinic prescribed for the cats, thus the difference in dosage.
I'm not familiar with Zeinquin but 10 days is usually enough to eliminate the infection. If your cat is showing any signs of discomfort in urinating or inappropriate urination after 10 days more antibiotic may be needed.
Bailey was on 10 days of Zeniquin last year for a UTI and it cleared it up. Katy was on 10 days of Baytril (she can't take Clavamox) a couple of months ago for a UTI, but it didn't completely clear it up so she's now on Zeniquin for 30 days. The vets are thinking that Katy's UTI probably wasn't cleared up completely with the Baytril because she's on prednisolone for her IBD and that suppresses her immune system. I would say that a 10-day course of an antibiotic is pretty normal in the usual situation.
