A disqualified dog is a dog that has lost its status as a purebred dog. It refers to a dog whose important physical characteristics do not meet the standards of a purebred dog due to various factors, thus becoming a disqualified dog breed. For example, the border collie is disqualified, which means that the border collie does not meet the standards. For example, the eyes are too far apart or too close together, and the eyes are too big or too small, the shape is not beautiful, etc.

Disqualification is generally used in various competitions. In modern times, it is mainly used in pet competitions. If the participating pet does not meet the pedigree standards of the breed of the event organization, it will not be able to participate in the competition.