Description: Believed to be a congenital condition, Iris Sphincter Dysplasia is due to the poor development of the sphincter muscles in the iris. Dogs with ISD are often observed to squint in the presence of bright light because their pupils fail to contract properly. This condition often predisposes cataracts and other abnormal conditions of the eye as the dog ages. Being congenitally-caused, there is no successful treatment for ISD thus affected dogs should be never be used for breeding.

Breeds Commonly Affected: Dalmatian