Genetic Test for Canine Leukocyte Adhesion Deficiency

According to the Merck Veterinary Manual (8^th ed., p. 583) Canine Leukocyte Adhesion Deficiency (CLAD) is a primary immunodeficiency disorder that is an autosomal recessive trait.  This deficiency is the result of a deficient expression of leukocyte surface glycoproteins.  Clinically, it is characterized by recurrent, severe bacterial infections; impaired pus formation; and delayed wound healing.  Infected animals usually have severe pyrexia, anorexia, and weight loss; response to antibiotic therapy is usually poor.

CLAD is an inherited fatal immunodeficiency disease. Pups that inherit two recessive genes for CLAD usually die early in life from multiple severe infections, even when treated with massive doses of antibiotics. It is related to the same disease in humans (LAD) and cattle (BLAD). So far, CLAD has been found only in Irish Setters and Irish Red & White Setters. Research on the disease was carried out in England and Scandinavia, where the carrier rate is close to 12%. However, CLAD was first identified clinically in the United States.

Reliable identification of dogs that do not carry disease genes is the key to eliminating autosomal recessive diseases such as CLAD. OptiGen offers a new DNA-based test that provides a method to eliminate Canine Leukocyte Adhesion Deficiency, or CLAD from the Irish Setter and Irish Red & White Setter.

As a mutation-based gene test, the OptiGen CLAD test unequivocally and specifically identifies normal dogs. Called "genetically clear," "noncarriers" or, more formally, "homozygous normals," such dogs can pass only the gene for normal leukocyte (white blood cell) function on to all their pups.

The test also identifies carriers (heterozygous dogs) with 100% accuracy. These carriers can be safely bred to "clears." Their recessive genes can only cause disease when matched with the recessive gene of another carrier. Performed early enough, this test will accurately identify affecteds as well. But affecteds usually don't survive to breeding age.

It isn't necessary to remove those carriers which are otherwise excellent dogs from the breeding population. But given the lethal nature of the disease, it is best to select against carriers who are not superlative dogs, so as to entirely eliminate the gene from a line within two or three generations.

To obtain more information about this available test, contact Optigen directly at 607-257-0301 or email genetest@optigen.com.  For additional information about the tests Optigen offers, visit their website, www.optigen.com.