Canine Leukocyte Adhesion Deficiency in Irish Setters

Canine Leukocyte Adhesion Deficiency (CLAD) is a serious inherited immune system disorder predominantly seen in Irish Setter puppies and the Irish Red and White Setter. This genetic condition is caused by a mutation in the ITGB2 gene, which disrupts the function of the beta-2 integrin protein essential for white blood cells to adhere to blood vessel walls and combat infections. Pups affected by CLAD are highly susceptible to frequent, often deadly infections.

The mutation specifically changes an amino acid (Cysteine to Serine) impairing immune cell function, preventing affected dogs from effectively fighting off viruses and bacteria. In the US, the carrier rate for this gene mutation among Irish Setters is estimated at about 5%, with a higher carrier frequency, around 13%, in the related Irish Red and White Setter breed.

What is CLAD and How Does it Affect Irish Setters?

Puppies born with CLAD experience significant immune suppression, leading to repeated severe infections and poor wound healing. Sadly, most affected dogs do not live beyond their first year. Early symptoms often include infections near the umbilical cord shortly after birth, persistent diarrhea, failure to thrive, and delayed recovery from minor injuries.

While dogs carrying one copy of the defective gene (carriers) typically show no symptoms, they can unknowingly pass the mutation to their offspring. This underscores the importance of genetic testing especially for breeding dogs.

Inheritance and Risk Factors

The disorder follows an autosomal recessive inheritance pattern, meaning pups must inherit two copies of the faulty gene, one from each parent, to develop CLAD. Carrier parents have one copy each and are healthy but can produce affected puppies if bred together.

• Clear parents: When both parents are free of the mutation, their puppies will not be affected or carriers.
• Carrier bred to clear: Approximately 50% of puppies will be carriers, while the rest will be clear.
• Two carriers bred: There is a 25% chance puppies will inherit CLAD, which is fatal.

In the US Irish Setter community, genetic counseling and testing are crucial to avoid carrier-to-carrier matings due to the import of genetic material from overseas.

Genetic Testing and Responsible Breeding Practices

Since carriers display no outward signs, DNA screening is essential before deciding on breeding pairs. Laboratories like Paw Print Genetics and Wisdom Health, recognized by the Irish Setter Club of America since 2020, provide reliable testing using either blood or cheek swab samples taken by your veterinarian.

Responsible breeders use these tests to ensure only clear or carrier-to-clear pairings occur, preventing puppies from inheriting two copies of the mutation. This practice helps maintain the health of future generations and reduces the incidence of CLAD in the breed.

Management and Research

At present, no effective cure exists for CLAD. Treatment focuses on preventing and swiftly addressing infections when they occur, although the prognosis remains poor and many affected dogs do not survive past infancy. Research into gene therapy is underway but still experimental.

Preventing the birth of affected puppies through genetic screening and selective breeding remains the best approach to controlling this deadly disorder.

Summary

Canine Leukocyte Adhesion Deficiency is a fatal hereditary immune disorder primarily affecting Irish Setter breeds. By embracing genetic testing and responsible breeding guidelines, owners and breeders in the US can reduce the risk and protect the health of these noble dogs. If you own or plan to breed Irish Setters, prioritize DNA tests and work with reputable breeders to safeguard the breed’s future.

For more information on finding Irish Setter puppies or locating reputable breeders in the US, consider trusted pet platforms and breeder clubs. Genetic health awareness contributes to a longer, happier life for your canine companion.