NEUTROPENIA WITH A PROBABLE HEREDITARY BASIS IN BORDER COLLIES

This paper documents a disease of Border Collies characterised by chro nic neutropenia which probably resulted in recurrent bacterial infecti ons manifesting as osteomyelitis and sometimes gastroenteritis. The ne utropenia occurred despite hyperplasia of the myeloid cells in the bon e marrow and a ''shift to the right'' in myeloid cell maturation. The underlying defect is currently unknown but may result from the inabili ty of neutrophils to escape from the bone marrow into the peripheral c irculation. Necrosis and new bone formation commonly involved the meta physeal regions of long bones. Other findings included a fasting hyper cholesterolaemia and the occasional presence of nucleated red blood ce lls in circulation, despite a non-regenerative anaemia. An autosomal r ecessive mode of inheritance is suspected. This condition has some fea tures of a rare human disease called myelokathexis which is also belie ved to have an autosomal recessive mode of inheritance.