Cranberry

Cranberry is used to support urinary tract health in dogs and cats because it contains proanthocyanidins (often called PACs) that can make it harder for certain bacteria, especially E. coli, to stick to the bladder wall. When bacteria cannot attach as easily, they are more likely to be flushed out during normal urination. This is why cranberry is mainly positioned for prevention support in pets that are prone to recurring urinary issues, not as a stand-alone solution for an active infection. 

In practice, cranberry works best as part of a broader urinary plan, alongside good hydration and regular toilet breaks for dogs. It should not replace veterinary care if a pet shows signs of a UTI such as frequent urination, straining, accidents, blood in the urine, pain, or lethargy. Cats in particular can have urinary problems that are not bacterial (for example stress-related inflammation), so getting the right diagnosis matters. Chou HI et al., 2016, Olby et al., 2006