Canine leukocyte adhesion deficiency (CLAD)
Canine leucocyte adhesion deficiency (CLAD) is caused by a defect in a surface molecule expressed by neutrophils which usually allows this type of cell to attach to vessel walls and move into tissues. Canine leukocyte adhesion deficiency is a primary immunodeficiency characterized by severe recurrent infections despite a marked leukocytosis. Clinical signs include frequent bacterial infections beginning shortly after birth and are accompanied by severe leukocytosis and a lack of purulent exudate. Omphalophlebitis, gingivitis, osteomyelitis, and pyoderma are frequent sequelae.
The genetic defect described above has only been described in dogs of the Irish setter breed and in a very small number of Irish setter crosses. The disease is inherited in a recessive manner, allowing some dogs to be carrier of the disease, without showing its symptoms. Researches esimate that more than 10% of Irish setters are carries of the disease gene. Due to this reason, genetic testing is vital prior to breeding. Affected animals are unlikely to survive beyond six months of age as they are unable to control widespread bacterial infections.
Foureman, P., Whiteley, M., and Giger, U. (2002). Canine leukocyte adhesion deficiency: presence of the Cys36Ser beta-2 integrin mutation in an affected US Irish Setter cross-breed dog and in US Irish Red and White Setters. J. Vet. Intern. Med. 16, 518–523.