Inherited Diseases

An inherited disease is one that may be passed from generation to generation through affected genes of the sire or the dam, or sometimes through a combination of both.

Genetics, the study of inheritance, is a highly complicated science, becoming increasingly so the more we learn of the subject.

There are two main problems in the control of inherited diseases in dogs. Some diseases are partly inherited, and partly occur as a result of some environmental influence, often difficult to determine precisely.

The inherited element may depend on several inherited factors rather than a single gene.
Typical of this type of disease is hip dysplasia, probably the most widely known of all inherited diseases of the dog. It is a hind-leg lameness, caused by severe erosion and damage to the hip joint.

It is generally considered that inheritance accounts for about fifty per cent of the clinical signs of hip dysplasia, and that the remainder is caused by some environmental circumstance - the dog's weight, exercise, diet, perhaps - but precisely what is not known.

In these circumstances, attempts at control are slow at best, depending on diagnosis of the disease and the avoidance of affected dogs in breeding. This may sound simple but is not.