Cyclic Neutropenia in Grey Collie Dogs

Cyclic neutropenia in a grey collie dog was first diagnosed at 10 weeks of age and has persisted 12 months. The average cycle length was 10.6 days with a range of 8 to 12 days. The condition was found in 2 other dogs of the type described and appears to be inherited along with a grey (silver) coat. The peripheral neutropenia results from a cyclic maturation arrest in the bone marrow at the level of differentiation from the stem cell.