Regarding cranberry supplements. http://skeptvet.com/Blog/?s=cranberry. (excerpt below)
Bottom Line
Despite some promising laboratory studies suggesting cranberry supplements might help prevent or treat urinary tract infections, the evidence of studies in clinical patients has been disappointing. Conflicting studies in humans suggest, on balance, that there is probably no significant benefit. And now a high-quality clinical trial in dogs has failed to find any effect, even in the the of infections the pre-clinical research most strongly suggested there should be one.
While the risks of cranberry supplements are probably negligible, pet owners should understand, and veterinarians should make in clear to their clients, that there is no good reason to believe they have any real value in preventing or treating urinary tract infections.
