Prevention of Distemper

Abstract

THE inquiry into the causation and prevention of dog distemper started in 1922 has now been brought to a successful issue by the Field Distemper Council, Dr. P. P. Laidlaw and Mr. G. W. Dunkin, the Medical Research Council and the staff of the Wellcome Foundation at Beckenham. The disease has now been accurately defined and distinguished from other dog illnesses with which it used to be confused; it has been shown to be due to an ultramicroscopic virus and efficient methods of prevention have been worked out in the laboratory and confirmed in large-scale practical trials on packs of foxhounds and other dogs. Dogs are first given an injection of an emulsion of the organs of an animal which has died of acute distemper in which the virus has been killed with dilute formalin; in response, the animal develops a moderate degree of resistance which makes it possible, a fortnight later, to give it a dose of live virus which stimulates the animal to become definitely immune. The blood serum of such immune animals can protect against the virus and is of use in treating cases of the disease and also in making a vaccinating mixture with live virus, which has the practical advantage of needing only one dose instead of two. These immunological reactions also make it possible to identify the disease with far greater certainty, and the new methods of prevention are available for ferrets, silver foxes, fitches, thinks, etc., in which it has been found to occur.