I've heard stories of blue merle border collies having health issues. I'm not talking about hearing problems, or merle/merle breeding , conformation lines or poor breeders now. These are all respectable working lines. This goes back 20 years or so, maybe no one has any answers here? I've "heard lBecause the merle gene is dominant, the dog really only needs one copy of the gene to produce this coat. When a Border Collie has two copies of the merle gene, there can be many complications in regard to health. These conditions may include deafness, mild blindness (abnormal small eyes) and overall poor health. The merle can be broken down
The undercoat is short, soft and dense for good weather-resistance. The length and composition of the coat makes the present day pedigree Border Collie unsuitable for work. Height: Males 48-56cm; Females 46-53cm. Weight: Males 13-20kg; Females 12-19kg. For the Border Collie Breed Standard, visit Dogs Australia. Temperament.
The Border Collie and Australian Shepherd are generally healthy breeds with few major health concerns. However, some common health issues can affect both breeds. One such issue is hip dysplasia , a hereditary condition that affects the hip joints and can lead to discomfort and mobility problems. This Border Collie type has a typical double merle coat pattern. However, the full pigment on the nose and around the eyes suggests that she may in fact just be a high-white normal merle. It would be unusual for a double merle to have so much pigment. Here we have a probable harlequin double merle. Harlequins are merles with a modifier that IH4M.