Why Are Your Dog’s Eyes Red and Swollen?

Dogs are nearsighted and see few colors, but their eyes still reveal a lot about their health. Red, swollen eyes can come from something simple like a speck of dust or shampoo, an allergy to food or the environment, or infection by bacteria, fungus, or parasites after a scratch or fight. Built-in problems also play a role: eyelid malformation (entropion or ectropion) and misdirected lashes rub the eye and cause chronic irritation. Because redness can also signal illness such as a cold or distemper, a vet check is wise when signs persist.