I'm amazed at some of the angry reactions that followed our publication of a news item last month on a hereditary disease called hyperelosis cutis (HC) or hereditary equine regional dermal asthenia (HERDA). Some of the researchers involved--Ann Rashmir, DVM, MS, Dipl. ACVS, associate professor of surgery and head of the Hyperelastosis Cutis Research Program at Mississippi State University, and Nena Winand, DVM, PhD, a geneticist and assistant professor in the Department of Molecular Medicine at Cornell University--have been bombarded with impolite e-mails and phone calls since they associated HC/HERDA with the Poco Bueno line of Quarter Horses. The disease is a death sentence--there is no treatment or cure. When a horse has HC, there is a lack of adhesion within the dermis, the deep layer of skin, due to a collagen defect. Think of it like glue holding the skin layers together, only with HC, the glue is inferior. Because the layers are not held firmly together, they separate. The end result generally is euthanasia. As a note to horse owners: Just because you don't like the message, don't kill the messenger. This isn't a surprise; folks at the 2004 American Quarter Horse Association meeting knew there was some hereditary skin disease associated with some lines of Quarter Horses, just like the Impressive line has been associated with the genetic disease HYPP (hyperkalemic periodic paralysis).

These researchers and others at the University of California, Davis, are working to solve this terrible disease. Davis researchers hope within two to three years to develop a genetic test to show which horses are carriers.

No one knows how prevalent HC/HERDA is, but it's a fact that people are buying afflicted young horses privately and at sales without knowing until it's too late (the condition usually doesn't show up until about age two when the horses start being trained and ridden). People are breeding these horses and some foals are born with the skin problem. Researchers are building herds of afflicted horses (and carriers) through donations from breeders and owners.

These afflicted horses and carriers are out there. Ignoring them won't make them go away, and it won't keep others from being born. The more researchers learn, the better able they'll be to help solve the HC/HERDA puzzle. Better to be cautious now and study pedigrees than to bring a foal into the world which has no chance of survival.

West Nile Virus Vaccines

Yes, everyone is confused when it comes to the WNV vaccines. Based on research from the companies, however, both seem to confer protection to horses. The take-home message here is to have a good working relationship with your veterinarian, learn all you can about the disease and the vaccines from your veterinarian and sources like The Horse, and make an informed decision on vaccinating your horses based on what the potential threat is in your area and on your farm.

Knowing when to vaccinate, what product to use, and when and how often to booster are questions that you must decide now in order to start protecting your horse before the mosquitoes show up. And don't forget that fall is the peak time of WNV infection in horses, so talk to your veterinarian about boostering your horses again before that critical time if WNV has been a problem in your area, or if there are signs it might be a problem this year.

Unfortunately, there is no way to know when and where WNV will be a problem. For example, one state had a drought that caused more cases because horses congregated at limited water supplies where mosquitoes lived. Another state had surplus rain that made mosquito breeding grounds out of every depression and ditch.

Remember that vaccination alone can't give your horses the best protection. You also must get out there and keep the mosquitoes from breeding, and keep them off of your horses (and you) and out of your barns.

Keep up with the latest on WNV through our web site at www.TheHorse.com/wnv.

About the Author

Kimberly S. Brown

Kimberly S. Brown was the Publisher/Editor of The Horse: Your Guide To Equine Health Care from June 2008 to March 2010, and she served in various positions at Blood-Horse Publications since 1980.

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