Hereditary canine cataracts are one of the most common disorders affecting various dog breeds; however, very little is known about cataracts. To date only mutations in one specific gene (the HSF4 gene) have been identified as associated with canine cataracts in some breeds. Yet numerous breeds, including Labrador and golden retrievers, Portuguese water dogs and huskies, analyzed by scientists at the Medical College of Wisconsin do not carry mutations in the HSF4 gene. In this Morris Animal Foundation–funded study the researchers evaluated 26 genes associated with hereditary cataracts in humans and mice to see if mutations in these genes may be responsible for hereditary cataracts in Labrador and golden retrievers, Portuguese water dogs and huskies. In spite of their enormous efforts, the researchers did not identify cataract associated mutations in these particular breeds. Still, these results suggest that certain breeds of dogs may harbor mutations in novel, not yet identified canine genes associated with cataracts.