Grey Collie Syndrome (GCS)

Cyclic neutropenia is a stem cell disease in which the number of neutrophils oscillates in weekly phases. Canine cyclic neutropenia is also known as grey collie syndrome, because it arose in Collie breed and affected dogs have hypopigmented coats.

Neutrophils are phagocytes, capable of ingesting microorganisms and some other particles. By this disease the number of neutrophils drops dramatically in a cyclical pattern, usually about every 10 to 12 days. During that time dogs have increased susceptibility to infection.

Affected dogs develop clinical signs very early in life. Affected puppies are usually smaller and weaker than their littermates. They have a noticeable pale grey, pinkish/grey or sometimes slightly yellow coat colour. By 8 to 12 weeks of age they develop clinical signs such as fever, diarrhoea, joint pain, or other signs associated with eye, respiratory, or skin infections. They are also prone to bleeding episodes. With proper treatment affected dogs can be kept alive, but few have lived beyond 2 to 3 years of age.

Inheritance: autosomal recessive

Mutation: AP3B1 gene

Genetic test: The method used for testing is extremely accurate and allows complete differentiation between affected animals, carriers and healthy dogs. Testing can be done at any age.