What breeds are more prone to tear staining?

Many of the breeds known for heavy tear staining share prominent, somewhat bulging eyes and shortened muzzles, a combination that often means tear ducts sit at an angle that drains less efficiently, allowing more tears to overflow onto the face rather than draining internally the way they do in most dogs.

Maltese, Shih Tzus, Lhasa Apsos, and Poodles are frequently mentioned for this tendency, and Pugs and other flat faced breeds add shallow eye sockets to the mix, which increases eye exposure and tear overflow further. Coat color plays a role too, since a Maltese's white coat shows staining far more starkly than a similarly affected dark coated breed would.

Daily wiping, keeping facial fur trimmed shorter around the eyes, and using filtered rather than tap water for drinking, since minerals in some tap water are thought to contribute to staining in sensitive dogs, are common management steps regardless of which prone breed you have.

A mixed breed dog descended from one of these prone breeds may show anywhere from minimal to significant staining depending on which physical traits, the eye shape, the muzzle length, the coat color, it inherited most strongly, so predicting staining tendency in a mixed breed puppy is harder than in a purebred dog of a known type.

Owners of these prone breeds sometimes find that switching to a stainless steel or ceramic water bowl, rather than plastic, helps slightly, since plastic can develop tiny scratches that harbor bacteria contributing to staining around the mouth and, by extension, sometimes near the eyes.