All Dog Breeds >>Health of Collie
Some collie breeds (especially the Rough Collie and the Smooth Collie) are affected by a genetic defect, a mutation within the MDR1 gene.Affected dogs are very sensitive to some drugs, such as Ivermectin, as well as to some antibiotics, opioids and steroids – over 100 drugs in total. Affected dogs also show a lower cortisol concentration than normal.
The Verband für das Deutsche Hundewesen (The German Kennel Club) encourages breed clubs to test all breeding stock and avoid breeding from affected dogs. A genetic disorder in collies is canine cyclic neutropenia, or Grey Collie Syndrome. This is a stem cell disorder.
Puppies with this disorder are quite often mistaken as healthy Blue Merles, even though their color is a silver grey. Affected puppies rarely live more than 6 months of age. For a puppy to be affected, both the sire and the dam have to be carriers of the disorder.