This is a synopsis of a presentation to veterinarians during The American Mustang session at the 2014 American Association of Equine Practitioners Convention, held Dec. 6-10 in Salt Lake City, Utah.

Feral mustangs managed by the Bureau of Land Management (BLM) require care different from your average domestic saddle horse. To explain, Albert Kane, DVM, MPVM, PhD, USDA Animal and Plant Health Inspection Service (APHIS) veterinary epidemiologist, shared information about the veterinary management of BLM equids at the 2014 American Association of Equine Practitioners’ Convention, held Dec. 6-10 in Salt Lake City, Utah.

The BLM is responsible for 49,000 horses and burros on 32 million acres of publically owned lands. The horses live on rangelands and in long- and short-term holding facilities. Additionally, the BLM performs postadoption compliance visits to monitor adopted animals’ health and welfare during the first year following adoption.

Overseeing these horses’ health and welfare requires employing trained personnel, including both veterinarians and wild horse and burro specialists. The BLM has developed an infrastructure of private practitioners, specialists, and wranglers to provide for the health of the animals under its jurisdiction, Kane explained. The BLM also relies on a partnership with APHIS to provide additional veterinary support and services.

Feral horses and burros are hardy animals that have survived harsh environmental conditions for several generations, Kane said. But they are still susceptible to illness and injury. The most common musculoskeletal problems veterinarians and managers see in the horses are club feet (which are often severe) and limb deformities.

The horses live in areas where food and water resources are often scarce. Kane described habitat where horses might have to use snow and puddles for hydration under extreme conditions and eat all types of edible shrubs and bushes during the winter. “Obesity is not an issue with mustangs in the wild,” he said, noting the frequent lack of winter grazing resources and the constant movement of bands.

While the horses can survive on limited resources, the overall belief that free-roaming feral horses are hardy and, therefore, immune to parasites and infectious disease is a myth, Kane said. “We find internal parasites—including ascarids, pinworms, and strongyles—in horses fresh off the range,” he said. “We especially see heavy ascarid burdens in horses of all ages, including in adults (in which you might normally expect to see immunity).”

The BLM tests all horses removed from the range for equine infectious anemia (using a Coggin’s test) and, under veterinary supervision, uses a vaccination protocol with periodic boosters to protect the horses from:

  • Eastern and Western equine encephalomyelitis;  
  • Tetanus;
  • Equine influenza;
  • Equine herpesvirus;
  • West Nile virus;
  • Strangles; and
  • Rabies.

Horses in holding facilities are especially susceptible to bacterial respiratory infections, such as Streptococcus zooepidemicus (which can cause upper respiratory infections or pneumonia) and S. equi (which causes strangles), as well as viral respiratory infections such as equine influenza and equine herpesvirus. The cause, Kane said, is the congregation of the immunologically naive and stressed animals while they adapt to captivity.

To protect horses from disease spread, the BLM follows biosecurity measures, which Kane acknowledged can be challenging when moving and handling large numbers of horses. Centers that receive horses from multiple horse management areas are emptied and cleaned to the extent possible, and handling facilities are disinfected prior to each use, he said, but respiratory outbreaks still happen from time to time. All horses transported over state lines do so with a brand inspection and health certificate.

Postadoption, wild horse and burro specialists perform compliance visits to adopter’s premises with assistance from APHIS veterinarians in some areas. The BLM also relies on private practitioners and often asks them to certify that adopted horses are receiving adequate care on the adopter’s title (ownership) application. “Poor hoof care is the biggest welfare issue postadoption for mustangs,” Kane said, noting that feral horses haven’t had their feet handled and require training to have their hooves trimmed or shod.

While the magnitude of the challenges sometimes seem overwhelming, the BLM’s goal is to keep the horses healthy, ensure they are treated humanely, and place them in good long term homes, Kane concluded.