<P> Hip dysplasia, Collie eye anomaly (CEA), and epilepsy are considered the primary genetic diseases of concern in the breed at this time . CEA is a congenital, inherited eye disease involving the retina, choroid, and sclera that sometimes affects Border Collies . In Border Collies, it is generally a mild disease and rarely significantly impairs vision . However, other eye conditions such as PRA slowly disintegrates the retina and can cause Border Collies to lose almost all of their vision at night which can progress into complete daytime blindness . There is now a DNA test available for CEA and, through its use, breeders can ensure that they will not produce affected pups . There are different types of hip testing available including OFA (Orthopedic Foundation for Animals) and PennHip . Radiographs are taken and sent to these organizations to determine a dog's hip and elbow quality . </P> <P> Two types of hearing loss occur in the breed . The first type is pigment associated and is found in Border Collie puppies, although the puppies can have congenital sensorineural deafness from birth as well . The second type is known as adult onset hearing loss . These dogs have a normal auditory brainstem response test as pups but gradually lose their hearing some time between one and eight years of age . A study is currently underway at The Translational Genomics Research Institute to identify the genetic cause of adult onset hearing loss in the breed . </P> <P> Neuronal ceroid lipofuscinosis (NCL) is a rare but serious disease that is limited to show Border Collies . NCL results in severe neurological impairment and early death; afflicted dogs rarely survive beyond two years of age . The mutation causing the form of the disease found in Border Collies was identified by Scott Melville in the laboratory of Dr. Alan Wilton of the School of Biotechnology and Biomolecular Sciences, University of New South Wales . There is no treatment or cure, but a DNA test is now available to detect carriers as well as affected dogs . </P> <P> Trapped Neutrophil Syndrome (TNS) is a hereditary disease in which the bone marrow produces neutrophils (white cells) but is unable to effectively release them into the bloodstream . Affected puppies have an impaired immune system and will eventually die from infections they cannot fight . The mutation responsible for TNS has been found in Border Collies in English working dogs, in show dogs that had originated in Australia and New Zealand, and in unrelated Australian working dogs . This indicates that the gene is widespread and probably as old as the breed itself . TNS was identified by Jeremy Shearman in the laboratory of Dr. Alan Wilton of the School of Biotechnology and Biomolecular Sciences, University of New South Wales . There is no cure, but a DNA test is now available to detect carriers as well as affected dogs . </P>

How many border collies are in the world