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The Covid-19 pandemic has accomplished one positive thing despite the great difficulties it has caused these past few years: People are more understanding about the contagion of infectious diseases. Horses are subject to infection brought in by traveling companions and new arrivals or obtained while visiting competitive venues. Their risk of exposure includes a number of infectious diseases, such as strangles (Streptococcus equi), equine influenza virus, equine rhinopneumonitis (herpesvirus), vesicular stomatitis virus, and Salmonella, to name a few.

The best cure for an equine infectious disease is prevention. Biosecurity measures protect horses on your property from disease outbreak and spread. Let’s look at some strategies you can use to help keep your horses safe, in no particular order:

Vaccination

Some infectious diseases are well-controlled using immunizations that target a specific virus or bacteria. Spring vaccines and fall boosters include protection against infectious respiratory viruses like equine influenza and equine rhinopneumonitis. There is a vaccine against the strangles bacteria, but it tends to be used primarily on at-risk horses.

To optimize disease resistance, administer vaccine boosters at least 2–3 weeks in advance of anticipated exposure. Boost viral respiratory vaccines twice a year for the best protection.

Disease cannot be solely controlled by vaccination since not all diseases have a related vaccine and not all vaccines are 100% protective against their target disease. Hence the need for a complete portfolio of biosecurity measures.

Managing New Arrivals

While a new arrival to a property may appear well, that horse can be incubating disease or be a carrier although not overtly sick. Even without demonstrating signs of sickness, such a horse can still shed disease. A sound strategy is to isolate new arrivals for 2–3 weeks to protect against any inadvertent spread of disease around the farm.

Horses that travel off-property to training, clinics, and competitive events are also an infection risk, so it is sensible to isolate them upon return, as well.

It is a good policy to ensure that any new horses admitted to the property come with specific veterinary evaluation, testing, and documents, including:

• A certificate of veterinary inspection
• A recent negative Coggins test for equine infectious anemia (EIA)
• A negative fecal exam prior to arrival and/or evidence that the horse has been dewormed in the preceding couple of weeks
• Nasopharyngeal swabs and culture to identify carriers of strangles, especially if coming from a previously infected property

Information about a horse’s travel history is relevant to check for any disease outbreaks at venues the horse has previously visited. The Equine Disease Communication Center tracks outbreaks and continually updates suspicious and confirmed equine infectious disease cases throughout the country.

Horses that arrive on the premises for training or a clinic should be separated from resident horses. This is often accomplished by simply tying the horse to its trailer when it is not being ridden, or by establishing separate stalls.

How to Manage an Isolation Area

To start, an isolation area should be located a sufficient distance apart from the resident population. There should be no opportunity for nose-to-nose contact or sharing of water between isolated horses and resident horses. A shared fenceline does not provide an adequate barrier (this also applies to neighboring properties).

As an example, protection against equine herpesvirus requires that exposed horses maintain a distance of at least 30 feet from others. Stricter regulations for EIA or piroplasmosis require 200 yards between suspected infected horses and other equids.

Help others be mindful of isolation boundaries by marking the boundaries with signs that limit access to only necessary personnel. Compliance depends on clear communication about biosecurity measures to all personnel on the farm, including boarders, visiting veterinarians, farriers, feed and bedding suppliers, and any other personnel coming in for repairs.

How long to isolate? This depends on the horse’s health status and management program at the previous facility and the incubation times for the pathogens of concern. Appropriate isolation periods are best decided in consultation with your veterinarian.

Monitoring for Signs of Disease

Health monitoring applies to horses away from home at an event, those returning after co-mingling with outside horses, and those in isolation. Track the following twice daily and record data in a daily log:

• Rectal temperature (each horse with its own thermometer)
• Appetite and feed intake
• Manure and urine output
• Presence of limb swelling
• Attitude
• General wellbeing
• Signs of sickness including cough, nasal and/or ocular discharge, lack of appetite, fever, diarrhea, neurologic instability

Know what is normal for horses in general so you can quickly recognize when something is wrong and contact your veterinarian immediately. Should an outbreak occur on the farm despite all attempts at prevention, have an action plan in place in consult with your veterinarian to minimize the impact of a disease outbreak.

Personnel Protocols

Besides restricting direct contact between new arrivals and resident horses, it’s important that personnel are aware of specific duties involved with isolated (or sick) horses:

• Feed and water resident horses first, leaving chores for new or sick horses until last
• When possible, assign a specific caretaker to be solely responsible for horses in isolation
• Drinking water sources remain separate
• Hoses used to fill tanks and buckets and to clean feed pans in isolation areas are disinfected as necessary
• Don’t share equipment like manure buckets, rakes, wheelbarrows, tractors, blankets, grooming tools, or tack between an isolation area and resident horses. Instead, an isolation area has its own designated tools and implements that remain there. It helps to label and/or color-code them for that purpose
• Exercise resident and new horses in separate areas when possible
• Non-porous boots and overalls maximize biosecurity measures. Booties or antiseptic footbaths to disinfect footwear are useful before entering and upon leaving a stall
• Appropriate disposal of contaminated cleaning and disinfecting solutions and bedding is important
• Removal of soiled bedding and delivery of feed should not be transported in the same equipment (wheelbarrow, tractor)

Insect and Animal Vector Control

Insect control is critical because flies can carry disease around a barn. Eliminating standing water also controls mosquitos, which can carry infectious (though not contagious) viral diseases like West Nile virus and encephalitis viruses (protective vaccines are available against these neurologic viruses).

Small animals like cats and dogs, as well as wild animals (rodents, raccoons, opossums), can also carry disease around a barn on their mobile bodies. Dogs that drink from or even jump into water tanks can carry strangles from one part of the farm to another. Opossums are known for contaminating feed sources with feces containing equine protozoal myelitis disease (EPM).

Deterrence of wild animals is accomplished best by storing feed in animal-proof containers, rooms, or buildings. And be sure to clean up spilled or leftover feed and regularly remove trash.

Identify and eliminate holes and cracks that create hidden nesting sites for small animals. Set out rodent traps and have barn cats to keep rodent populations in check.

Human Hygienic Practices

People can serve as vectors for communicable diseases through their hands, nasal passages, clothing, and boots. Frequent farm visitors include trainers, farriers, veterinarians, alternative practitioners, hay delivery folks, and repair personnel.

Such individuals may visit many barns and horses throughout their day and could potentially spread infectious diseases from one barn to another.

Enforcing good hand hygiene is important for all: Scrub with antiseptic soap while singing “Happy Birthday” twice to allow sufficient contact time with soap before rinsing. If no water is available, use hand sanitizer gel with a minimum of 60% alcohol.

Trailer Strategies

It is best to park visitor vehicles and trailers a sufficient distance away from the barn and resident horse trailers. If there has been any suspicion of contact with an infectious disease at another farm, new clothing and boots should be donned and contaminated garb placed into plastic garbage bags for laundering. Bactericidal and viricidal footbaths help to contain infection. However, it may be more appropriate that the person with suspect infectious contamination return another day after showering and wearing clean clothing and footwear.

Horse trailers can also be a source of infection from horses’ secretions on interior surfaces as they travel on and off the property. A cool and moist trailer environment can harbor infective levels of the equine influenza virus for 7–10 days; in manure, herpesvirus remains infective for as long as 35 days.

Soiled feed, water, and manure from a trailer are best disposed of in compost piles away from the resident herd or put into dumpsters for trash removal.

Park trailers that come and go in an area away from resident horses and clean and disinfect them with appropriate products. Spray inside and out with pesticides. Don’t forget that your truck may also harbor infectious material from your hands and boots, so clean floor mats and sanitize the steering wheel and console.

Off-the-Farm Strategies

If only limited special isolation measures can be taken once horses return to the barn during a busy training and competition season, then at the very least, follow biosecurity measures while away.

Avoid nose-to-nose contact with other horses from different barns. Don’t touch or handle other people’s horses, and don’t allow others to touch or feed your horses. Use antiseptic hand gel liberally. Refrain from sharing other horses’ tack and equipment with your horse.

Stabling away from home brings your horse into potential contact with contaminants from other horses that have used that stall. Remove residual feed, bedding, and debris from the stall. When possible, scrub walls, water containers, and smooth surfaces with a detergent, then apply disinfectant.

Apply disinfectant specifically labeled against viruses and bacteria by following the manufacturer’s directions and allowing a contact time of 1–5 minutes. A list and explanation of effective disinfectants are available at the Center for Food Safety & Public Health.

Bring your own feed and water containers to use exclusively for your horse so your horse doesn’t need to drink from common water sources. Communal watering sources contain nasal secretions, saliva, and other potentially communicable material.

Avoid filling small buckets from large tanks contaminated by other horses, and avoid using a hose that has been dunked into a common-use water tank. Also, refrain from dunking wash sponges, bits, or hands into communal water tanks. Use a separate bucket of water specifically for that purpose and then discard fouled water. Similarly, prevent your horse from accessing leftover piles of hay or spilled grain around the venue as this risks exposure to other horses’ oral and nasal secretions.

The Bottom Line

Biosecurity measures may seem labor intensive, but they can yield both time and financial savings. Mitigation works best when everyone on the bar and on the road follows these protocols. Ultimately, the objective is to keep the health of your herd as robust as possible by following straightforward biosecurity steps