I have found many references to uva ursi on the Veterinary Information Network but dosing information is hard to come by.
For most herbs we don't know the exact dosage that should be effective. So, when we don't know, we usually tend to extrapolate from the human dose. The medication should have a dose on the bottle which is safe for humans to take. For a dog of 70 lbs you would generally give 1.5-2 times the dose that is recommended for humans. (I know it seems backwards, but dogs usually need a higher dose of most medications or supplements than people).
Uva Ursi is not a totally benign drug though. Given long term it can reduce potassium levels. It can be toxic
if given in too high a dose as well. If I was recommending it to a patient I would use it for 4-5 days in a row when it seems like an infection is brewing, but I would not use it long term.
And again, if you do use this medication you will need to do so on the ok of your veterinarian.
I hope this information helps! If you have more questions regarding this problem, just hit reply. If I am online I will respond right away. Otherwise I will respond as soon as I come online again. Or, if my answer is sufficient, then please hit accept. Thanks!
The above is given for information only. Although I am a licensed veterinarian, I cannot legally prescribe medicines or diagnose your pet's condition without performing a physical exam. If you have concerns about your pet I would highly advise contacting your regular veterinarian.