What do dog tear stains look like?

Tear stains are reddish-brown marks at the eye corners caused by tears accumulating around the eye. Normally tears drain through the tear ducts, but blockage or overproduction lets them build up and form stains. The owner can clean the corners with a cotton ball or gauze dipped in warm water.

Also, antibacterial eye drops can control inflammation and prevent infection. If stains persist, see a vet.