Crananidin Urinary Tract Support is a scientifically formulated cranberry extract product. It's given to help support urinary tract health in dogs. Crananidin's cranberry extract contains compounds called "proanthocyanidins" or "PACs". These PACs work to help stop certain bacteria from "sticking" or attaching to the inner lining of the bladder wall allowing the bacteria to be flushed out in the urine. Crananidin has been researched, and its PACs have been shown to limit the attachment of the bacteria. The same cannot be said for other cranberry supplements marketed for urinary tract health in dogs. These other supplements were found to contain some PACs, however, their PACs were not able to stop the bacteria from sticking.