Biosecurity in the Breeding Shed

While we often think of biosecurity practices in relation to traveling competition horses and busy equine clinics, we can’t overlook the importance of good biosecurity on breeding farms.

Photo: Anne M. Eberhardt/The Horse

Biosecurity has become a buzzword in the equine industry in recent years in the wake of various high-profile disease outbreaks. It’s significance—to keep the country disease-free and to prevent major economic losses--can’t be understated.

And while we often think of biosecurity practices in relation to traveling competition horses and busy equine clinics, we can’t overlook the importance of good biosecurity on breeding farms. A contagious equine metritis (CEM) outbreak in 2008, for instance, affected 23 stallions and cost the industry nearly $2 million.

David Scofield, DVM, MS, Dipl. ACT, of Select Breeders Services, in Chesapeake City, Maryland, is one reproduction veterinarian who feels very strongly about biosecurity in the breeding shed. He faces daily disease risks at their breeding facility, not just from incoming and outgoing stallions and mares, but also from the farm’s proximity to other breeding farms. Scofield shared his smart practices for breeding shed biosecurity at the 2016 Theriogenology Conference, held July 27-30 in Asheville, North Carolina.

Sources of disease spread at breeding farms, said Scofield, include horses (both resident and trailer-ins, as well as tease mares), humans (grooms, employees, visitors), semen, and wildlife. But the biggest concern? Humans.

Scofield said he separates disease risks into three categories. “By identifying categories we can decide where to make decisions to intervene, if possible,” he explained. These include:

  1. Geographic-based—in other words, what diseases horses in your area can be exposed to (e.g., rabies, Rhodococcus equi, vesicular stomatitis)
  2. Venereal (e.g., equine arteritis virus [EAV] and CEM)
  3. Contagious (e.g., equine herpesvirus, influenza, strangles)

To help prevent transmission of any of these diseases, Scofield and his group have in place mandatory requirements for all incoming horses. These include Coggins testing for equine infectious anemia, bacterial screening of stallions, proof of vaccination against EAV, virus isolation on EAV-positive stallions to determine carrier state, and, depending on the horse’s location, vesicular stomatitis testing.

On-farm biosecurity steps include stringent routine cleaning and disinfecting, barrier protection (e.g., gloves and protective clothing), and record-keeping. Staff and client communication, he said, are crucial to staff and groom participation. “Talk to clients and explain to them why you’re doing what you’re doing,” he said.

Scofield then described disinfection protocols and products in more detail.

“Disinfectants are designed to destroy bacteria and viruses on inanimate objects,” he explained. “No one agent is perfect for all applications.”

The various disinfectants used in veterinary practice include:

Alcohols, which Scofield said are one of the most common. They are fast-acting and broad-spectrum (meaning they’re effective against a large variety of organisms) but highly flammable and can irritate the skin.

Aldehydes, which are broad-spectrum and noncorrosive, unlike some other agents, but come with safety concerns, as some are carcinogens, or cancer-causing.

Biguanides, such as chlorohexidine, are only effective against bacteria, not viruses and fungi. They are also inactivated by soaps and detergents, said Scofield.

Halogens, such as iodine and chlorine (bleach), are broad-spectrum. Iodine, however, stains surfaces and loses its potency over time. Chlorine, while cost-effective, is corrosive and inactivated by light, said Scofield.

Oxidizing agents, such as hydrogen peroxide, are another very commonly used disinfectant, said Scofield. These are broad-spectrum and good for use on hard surfaces. However, they can be irritating to the skin and eyes in concentrated forms.

Phenols are broad-spectrum and remain fairly active in the presence of organic material. Note, however, that they are toxic to some small animals, said Scofield.

Quaternary ammonium compounds are effective against bacteria and viruses, but they are easily inactivated by organic matter such as straw, bedding, dirt, and feces, said Scofield.

Before applying your disinfectant of choice, Scofield suggested taking into consideration topography, temperature, humidity, and the presence of debris, which can inactivate disinfectants. Remove organic matter from the surface and wash, scrub, rinse, and dry.

Then it’s time to disinfect. Choose the proper agent, dilute it down to the proper concentration (remember, these are chemicals, Scofield said), make sure it has enough contact time to be effective, then rinse and dry the area.

The next step in the biosecurity process, said Scofield, is monitoring. This includes staff-initiated checklists, visual inspections to make sure staff has attended to each section of the shed biosecurity program, and taking bacterial cultures from breeding phantoms, artificial vaginas, water sources, and other sites.

Each area of the facility—long-term and short-term holding, quarantine stalls, paddocks, sheds, and the laboratory—will have its own specific biosecurity plan based on American Association of Equine Practitioners guidelines, he said.

“No one program works everywhere,” said Scofield. “And even with the best intentions, there will be breakthroughs.”

He recalled, for example, once watching the resident barn cat stroll into a recently disinfected stall and dip his foot, containing who knows what pathogens and fomites, into the horse’s water bucket.

In summary, said Scofield, “Written protocols guide things, and facility-cleaning, record-keeping, and testing requirements are imperative for trace back,” in the event of disease.

About the Author

Alexandra Beckstett, The Horse Managing Editor

Alexandra Beckstett, Managing Editor of The Horse and a native of Houston, Texas, is a lifelong horse owner who has shown successfully on the national hunter/jumper circuit and dabbled in hunter breeding. After graduating from Duke University, she joined Blood-Horse Publications as Assistant Editor of its book division, Eclipse Press, before joining The Horse.

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