It has long been known that the tendency to develop allergies, including allergic lung problems, can run in families, both human and equine.
A study performed at the University of Berne, Switzerland, has identified at least one candidate gene that might be involved in the equine allergic lung disease and RAO, or recurrent airway obstruction, commonly known as ”heaves.”
The researchers found a link between changes in genes controlling the interleukin-4 receptor (IL4) in the foundation sire of one family of warmblood horses prone to RAO, but not in another. IL4 is a cytokine (cellular messenger protein) involved in human asthma.
Bottom Line: The risk of developing lung allergy isn’t likely to turn out to be as simple as a single gene, but ongoing work on the genetics of this important lung disease may make it possible in the future to screen breeding stock and to identify horses at risk earlier, so that proper management and treatment can begin before lung damage is advanced.