Seven Ponies Dead from R. equi Outbreak in Mayotte

Seven ponies have died at an equestrian center located on the Indian Ocean island of Mayotte following a Rhodococcus equi outbreak, according to local agriculture officials.

The Departmental Federation of Farmer's Unions (FDSEA) of Mayotte reported that two other ponies at the Hajangua equestrian center on the eastern coast of the Mozambique Channel were infected but have been treated and are recovering. Health officials have placed the facility under quarantine until the epidemic is considered resolved.

"The managers of the center have acted very responsibly in this situation, working closely with veterinarians and breeding professionals," an FDSEA press release read.

Guillaume Chenut, DVM, associate director of the region's Department of Agriculture (DAF), revealed that laboratory analyses results of blood samples taken from horses residing at the equestrian center revealed the presence of R. equi, according to the Internet news site Malango Actualité.

R. equi is an opportunistic bacterium that often causes bronchopneumonia in foals up to about 5 months old, but it does not usually affect adult animals unless they are immunosuppressed, according to Robert van der Geize, DVM, PhD, molecular biologist and head of the molecular pathology department of the Laboratorium Pathologie Oost Nederland, in Enschede, the Netherlands. Van der Geize recently worked for several years on developing a vaccine against the disease with some success.

"It is indeed unexpected that adult ponies would be affected by a Rhodococcus equi infection, and in fact a serious outcome of the infection is mostly observed in foals," van der Geize said.

A change of equestrian center ownership last summer might have influenced the ponies' health, Malango Actualité reported Chenut as suggesting. "Even though the center was well taken care of, this simple change could have disturbed its balance," he was quoted as saying. Social conflicts in the region leading to reduced access to feed might also have played a role, resulting in the ponies grazing at pasture more than they otherwise would have, he added. Chenut could not be reached directly by The Horse for comment.

R. equi can survive and reproduce inside a horse's lung cells but is also found in their droppings, according to van der Geize. Treatment with antibiotics is usually long and expensive and unfortunately not often successful.

The riding center remains open for activities, according to the FDSEA, despite being under quarantine and significant hardship after losing more than a third of its equine tenants.

"The loss of their animals represents not only an economic loss but an emotional one as well," the FDSEA release stated.

About the Author

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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