MCD is an inherited eye disease that causes problems with a dog's sight. In affected dogs, a build up of carbohydrate causes the surface of the eye (the cornea) to become cloudy.
Dogs with MCD usually show signs around four to six years old. Affected dogs will have cloudy eyes that may have grey or white spots on the surface. As their eyes become cloudier, they may have problems seeing and may be more likely to bump into things, walk more slowly or may be more nervous when visiting new places.