Earlier this month the American Hanoverian Society was made aware of a U.S. warmblood foal that veterinary and genetic experts determined to be afflicted with a rare genetic disease referred to as Warmblood Fragile Foal Syndrome (WFFS).
WFFS foals exhibit extreme skin fragility, especially at the joints. The disease cannot be treated or cured and is invariably fatal, typically soon after birth. This disease manifests itself only when a foal receives a copy of a certain recessive gene from each of its parents. Only horses that are homozygous for this condition (that is, horses that carry two copies of the recessive gene) exhibit the full effects of the syndrome. Horses that are heterozygous for this condition (that is, horses that only carry one copy of the recessive gene received from either parent) are referred to as "carriers" of the gene, but otherwise display no known outward effects of the disease. WFFS requires two copies of this gene for expression (referred to as a recessive autosomal trait), so a single copy can be carried through multiple generations of animals before being expressed.
At present, the only company in the U.S. with a commercial test available for detecting this recessive gene is Animal Genetics Inc. of Tallahassee, FL (http://www.animalgenetics.us/Equine/Genetic_Disease/WFFS.asp). UC-Davis, which currently handles genetic parentage verification for the AHS, is currently developing its own test. For now, AHS members, in consult with their veterinary experts, may wish to consider having their breeding animals tested to determine whether any are carriers and to develop strategies for avoiding matings between two carriers.
For the past two weeks the AHS Board has been in communication each other, with the Hanoverian Verband, and with veterinary and industry professionals in this country to understand this disease and its impact on warmblood breeding both here and abroad. WFFS appears to be a very rare disease, with only an extremely small number of cases reported, the first of which was reported in the journal Veterinary Researchin 2015, about a foal born in 2012: (https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-015-0318-8).
The AHS has asked Dr. Doug Langer and Dr. Barbara Schmidt, two highly qualified veterinarians and members of the Board, to form a task force that will analyze WFFS and its potential ramifications and provide further recommendations to the Board during its next meeting in June. As a society we are aware of and appreciate our membership's concerns on this issue. If our members would like to share their thoughts, please email them to the Board care of AHS Executive Director Hugh Bellis-Jones at firstname.lastname@example.org.
The AHS will continue to communicate to our members as more information and updates become available. In closing, we would like to thank you for your continued interest and passion for the Hanoverian breed.