Be proactive rather than reactive with equine biosecurity

“In the equine industry, true biosecurity is hard to achieve because horses move around a lot, and many diseases are always present,” says Ontario Veterinary College infectious disease specialist Dr. Scott Weese. “However, it's still important to try to prevent diseases from entering and to have plans in place to manage any outbreaks.”  With frequent horse movements, endemic pathogens and emerging diseases, there is a need for improved understanding and motivation to adopt better infection control practices.

Infection control begins in the barn and works best when the focus is pro-active rather than reactive.  This includes having an access management plan, proper quarantine protocols for new and returning horses, and training EVERYONE who comes on to the property or handles the horses.

Access Management

Controlling how horses, humans, equipment and vehicles can move into and around your farm are all aspects of access management aimed to reduce the transmission of pathogens.  

Access management begins at the entrance, where a training facility may use fencing and gated entries to restrict access to the stables and training areas, ensuring only authorized personnel can enter.  Procedures at controlled access points such as hand sanitizing and boot cleaning help prevent the spread of infections.  Both staff and service providers need to be made aware of any infection control measures in place.  Clean outerwear that has not been worn to another barn are also recommended to prevent potential spread of disease.

A sign in procedure can be made mandatory for visitors.  A log can be helpful to help trace the problem in the event of a disease outbreak. Providing guided tours can ensure they do not enter restricted areas.  Additional signage can let visitors know where they can and cannot go.

Controlled access zones can designate specific areas for different activities, such as quarantine zones for new arrivals and separate zones for resident horses, with controlled access points to manage movement.

Isolation/Quarantine

When horses return home or new horses arrive, such as from a sale, it is a good idea to implement quarantine and/or isolation protocols.  Ideally this involves housing in a separate building away from your resident horses, but it may be the end of an aisle with several empty stalls in between.  

New and returning horses are kept separate and monitored for at least 14 days.  This involves twice daily temperature checks and health checks including watching water consumption, appetite, urination, manure and any signs of illness.

Turn out paddocks should also be away from other resident equines, especially if that includes higher risk horses like broodmares and foals.  

Effective quarantine includes using separate equipment for isolated or quarantined horses to avoid cross-contamination.  This includes water buckets, feed tubs, grooming equipment as well as wheelbarrows, brooms, pitchforks and other cleaning tools.   

Ideally, new and returning horses are handled by separate staff.  Otherwise, quarantined horses are worked with last & hands are washed before & after each interaction.  Strategically placed alcohol-based sanitizers can also be used.  If wash stations are limited, this makes it easier for staff and visitors to follow infection control protocols.  Disposable gloves, disposable shoe covers & protective clothing are also best practices.  Barn cats and other pets should not be allowed to enter the quarantine area.

If you have a number new or returning horses in quarantine and one shows signs of illness, it should be further separated into isolation and seen by a veterinarian ASAP.  Horses should remain in isolation until cleared by the vet, as the horse may have recovered from clinical signs but still be infectious.  Signage once again should alert unauthorized persons at the entrance of any areas used for isolation or quarantine.

Not Sharing is Caring and Hygiene Practices

Of course, those new or returning horses should be housed in a stall that has been both cleaned and disinfected prior to their arrival.  

Cleaning involves removing all visible manure, bedding and soil before washing the area with soap and water and then allowing it to dry.  Then apply a disinfectant such as Virkon or other disinfectant recommended by your veterinarian.  All disinfectants have strengths and weaknesses and are best used for specific purposes.   Bleach has drawbacks as hard water can affect its effectiveness, it can be inactivated by organic material, and it can be irritating to the horse.  Steer clear of pressure washers as they can aerosolize certain viruses.  

An often-misused step, if you will pardon the pun, is the foot bath.  One cannot just walk through without first going through the same routine as mentioned above, both cleaning and disinfecting.  First remove debris from the footwear, including the soles using a brush or hose to get all the dirt out of the treads.  Immerse the entire bottom of footwear in the disinfectant and scrub.  Following the contact time on the product label is important and a dirty footbath does little in the way of boosting biosecurity.  Then wash your hands.  Other options include dedicated footwear and disposable shoe covers.

Hand hygiene cannot be overstated as one of the most important infection control measures.  Best practices on application time for the soap or alcohol-based sanitizer is 20 – 30 seconds.

Everyone knows not to share communal water, but it is also important not to become blasé about biosecurity when it comes to filling or refilling water buckets. Submersing a hose from one bucket to the next or letting it touch the buckets can be a free ride for a pathogen looking for its next host.  So instead of multi-tasking while filling buckets, one could be enjoying a beverage with their free hand. 

Not sharing should extend beyond grooming equipment to tack, pads, blankets, and of course medical supplies like syringes, needles and dewormers.

More disease prevention measures include minimizing the presence of rodents and insects by keeping feed secure, eliminating standing water and regular removal of manure from stalls and paddocks and as well as management of manure storage areas.

Vaccination

Vaccination is a crucial aspect of equine healthcare, but vaccines do not provide immediate protection; it can take days or weeks for a horse to develop optimal immunity after vaccination, so timing is very important.  Planning ahead will allow vaccines to be given well in advance of the next stressor such as travelling or competition.  

While no vaccine boasts 100% immunity, horse owners can rest assured that they are taking proactive steps to maintain their horse's health, minimizing the risk of unexpected veterinary expenses.  Vaccines significantly reduce the risk of disease which means if a vaccinated horses does get sick, they will generally experience milder symptoms and recover more quickly.

Working closely with a veterinarian to develop and maintain a vaccination program is an important step for optimal equine health.  In addition to core vaccinations, your vet will know what diseases are endemic and emerging in your region or regions you will be travelling to.   The frequency of your vaccinations or boosters will depend on a number of factors including special circumstances, such as an extended vector season or even a significant wound if it is incurred over 6 months after a Tetanus shot.  The length of your competition season may also necessitate a booster of certain shots to maintain optimal immunity. 

Emerging Diseases

Infection control specialist Dr. Weese says, “Understanding potential mechanisms of transmission is the basis of any infection control or biosecurity program.”

Most diseases in horses are caused by pathogens that mainly infect horses. They can spread continuously without needing long-term hosts (like the equine flu virus).  They can remain in the horse without causing symptoms for a long time (like Strangles). Some cause infections that can come back at any time (like equine herpesvirus).  Others may be part of the normal bacteria in horses but can cause disease if given the chance (like staphylococci and Enterobacteriaceae).

Horses can spread these germs even if they seem healthy, before showing symptoms, after recovering, or as part of their normal bacteria. This makes it hard to identify which horses are infectious. Some symptoms, like fever and diarrhea, strongly suggest an infection, but any horse can potentially spread germs. Therefore, it's important to have strong infection control practices to manage the risk.

In 2024, the Equine Disease Communication Center (EDCC) reported 577 Alerts for 813 confirmed cases of disease in North America. The most frequently reported disease was Strangles with 186 cases. Because Strangles is not reportable in all states or provinces the disease is likely much more prevalent than reported to the EDCC. Other frequently reported illnesses include: 153 West Nile Virus (WNV), 125 Eastern Equine Encephalitis (EEE), 109 Equine Infectious Anemia, 73 Equine Herpesvirus- Neurologic, 8 Equine Herpesvirus- Respiratory, 34 Equine Influenza.

1. Strangles: A bacterial infection caused by Streptococcus equi, leading to swollen lymph nodes and respiratory issues.  It is highly contagious and spread through contact.  This could be nose-to-nose between horses or via contaminated surfaces or equipment such as: shared halters, lead shanks, cross ties, feed tubs, stall walls, fencing, clothing, hands, the hair coat from other barn pets, grooming tools, water buckets, communal troughs. 

After an outbreak, cleaning should involve removal of all organic material from surfaces and subsequent disinfection of water containers, feeders, fences, stalls, tack and trailers. 

1. West Nile Virus (WNV): a mosquito-borne virus leading to neurological issues such as inflammation of the brain and spinal cord.  WNV can be fatal and survivors can have residual neurological deficits for a period of months to permanent disability.

2. Eastern Equine Encephalitis (EEE): another virus transmitted by mosquitos Eighty to ninety percent of infected horses develop acute and fatal neurologic disease.  

3. Equine Infectious Anemia (EIA): is a blood-bourne virus which can be transmitted by insects, medical equipment or passed from mare to foal in utero.  With no treatment or cure, horses confirmed positive by a Coggins test can be quarantined for the rest of their life but are usually euthanized.

4. Equine Herpesvirus (EHV): This virus had multiple strains and can cause both abortion and neurologic symptoms.  Spread via aerosol particles from nasal discharge or from contaminated surfaces.  There are vaccines for respiratory and abortive strains but not the neurologic form of EHV-1 (EHM).

These diseases highlight the importance of biosecurity and vaccination in managing equine health.  West Nile Virus and Eastern Equine Encephalitis are among the core vaccinations recommended by veterinarians.

In February 2025, Equine Guelph partnered with the Equine Disease Communication Center (EDCC), to help horse owners assess and manage infectious disease risks with the relaunch of Equine Guelph’s Biosecurity Risk Calculator (TheHorsePortal.com/BiosecurityTool).  The interactive free tool is full of useful information from quarantine protocols, best practices for cleaning, and easy to understand practical access management tips.  In just 10 minutes, you can assess and minimize biosecurity threats for your barn.

"Applying routine and basic biosecurity is the best way to prevent infectious diseases," says Dr. Nathaniel White the Director of the EDCC. "This includes isolation of new horses introduced to facilities, monitoring horses' temperature and preventing horse to horse contact while traveling and keeping vaccinations up to date. Being aware of disease prevalence using information from the EDCC and the updated "Biosecurity Risk Calculator" can help owners use management practices to decrease disease risk." 

Equine Infection Control Measures During Transport

Pre-transport preparations entail more than just having your paperwork in order.

Taking the time to clean and disinfect the trailer or make sure the trailer you have hired always cleans between loads is of paramount importance.  If the trailer smells like horses, it was not adequately cleaned.  Perform a horse health check before you leave the property.  It is not worth the gamble to stress a horse with travel when it is ‘not-quite right’.  

Being particular about your horses traveling companions is just as important as the cleanliness of the trailer.  Avoid travelling with horses from other locations as being in close quarters increases the risk of picking up an infectious disease.

Tie the horse loosely if possible.  Horses tied short are less ability to lower their head to clear mucus.  Allowing freedom of head movement can reduce stress and the bacterial load in the airways.  Similarly, hay nets that are hung high, encouraging a high head position, and introducing dust and debris, can challenge mucous clearance.

Ventilation is another important consideration as improving air exchange can reduce the dust and mold spores hanging in the air.  Drafts on the other hand can blow particles around in the trailer.

Many prefer shipping in leather halters because they will break in an emergency but there is a biosecurity benefit too as they are easier to clean.  Bacteria can linger in the webbing of polyester halters.

Biosecurity is just as important on the road and when visiting other venues. Disease is easily spread through equipment sharing.  While visiting venues off the farm be sure to bring your own broom and shovel for cleaning your trailer.  Be sure to pack a thermometer along with your tack and other equipment.  Clean & disinfect your equipment when you get ready to leave your off-site location.

Upon returning to the home farm, the cycle begins again, monitoring horses for possible delayed onset of symptoms.

To ensure effective infection control, it is crucial to maintain a proactive approach starting right in the barn with a plan. Implementing access management, enforcing proper quarantine protocols for new and returning horses, and thoroughly training everyone who enters the property or handles the horses are essential steps. By taking these practical steps, we can significantly reduce the risk of infections and promote a healthier environment for all.

"BioSecurity" on the backstretch

Article by Ken Snyder

Cleanliness, or biosecurity, is essential to horse health and is at the core of minimizing infectious disease outbreaks and subsequent quarantines. Failures in biosecurity can mean canceled race days; idle trainers; and most important and awful, dead or injured horses.

Recent history reveals the importance of biosecurity on both the racetrack and also Thoroughbred breeding farms. In 2021, a life-threatening Rotavirus B outbreak in foals swept through farms in Central Kentucky, taxing farm staff and management with contagion containment. 

More recently, in 2022, an outbreak of equine Herpesvirus-1 at Churchill Downs resulted in a quarantine of as many as 13 horses in one barn. Contagiousness of this EHV-1 meant horses even indirectly exposed to horses with the virus were also quarantined in two other barns.  

EVH-1 isa far more serious threat in that more horses risk exposure on racetracks than on a farm. The virus causes respiratory disease, neonatal death, and neurologic disease, EHM (equine herpesvirus myeloencephalopathy). EHM is often fatal and if not, can leave long-term problems. Symptoms presenting EHM are heart-rending: Horses will lack coordination, have weakness or paralysis in some or all of their limbs, and become unable to balance or stand.

Contact and contagion are the dangers to horse health with viruses like EHV-1 or rotavirus B. Horses travel, and Kentucky might be the busiest crossroad in the world with Thoroughbreds coming in from all points in the country and world and traveling out to racetracks out-of-state and, of course, foreign countries. Experts agree that every effort has to be made in this state and elsewhere with biosecurity to prevent repeats of what happened last year and in 2021. 

They also are in agreement that trainers are the first line of defense.   

Because they see and care for horses daily, trainers will be the first to note abnormalities or symptoms of disease, according to Dr. Stuart Brown, vice president of equine safety at Keeneland Race Course.

“Trainers are the sentinels, the keepers of horse health, them and their attending veterinarians,” he said. “They're at the forefront of working with regulatory veterinarians as well as the state veterinary offices to maintain a healthy population of horses.”

The consensus among industry people like Brown is that trainers, with only a small minority of exceptions, do an excellent job because so much is at stake.

“By and large, they’re all very attuned to disease transmission,” echoed Dr. Will Farmer, equine medical director for Churchill Downs and all other racing properties. 

They have to be, he added. “If a trainer has a sick horse, a groom is taking care of it and multiple horses. There’s the possibility of spreading a disease. Trainers are very keen on biosecurity.“ 

Trainers, especially, must be sensitive to biosecurity in their barns as they move their stable from one race meet to another and new stalls for their horses. 

“I’ve shipped everywhere—Gulfstream, Tampa, New York a lot, Laurel a lot,” said Ian Wilson, assistant trainer to Graham Motion, naming only a few of the destinations for horses at the Fair Hill Training Center in Maryland.

He’s encountered conditions he described as “generally good.” 

“You never walk into a stall and say, ‘This one needs another bag of shavings or another bale of straw.’ 

“Where our concern lies is what you don’t know. A clean stall and a dirty stall sometimes don’t look that different.” 

Receiving barns, which especially should be as pathogen-free as possible, is not guaranteed. “In New York, I know the gentleman who takes care of the receiving barn and he does a really, really, nice job of it. I’ve watched him clean a stall, and he does it properly. In other places, I’ve seen them pick over a stall really quickly, and off they go.”

While disease outbreaks are sporadic, the goal, of course, is minimizing the maximum potential for occurrences. A mantra for Brown at Keeneland is “the solution to pollution is dilution.” In other words, every resource—human and inanimate—should be brought to bear to combat the potential for disease development, particularly with the cleaning and disinfecting of stalls. Every measure, however, will only dilute or reduce issues that arise.

While receiving barns will have straw down and should be clean, standard operating procedure for trainers moving horses from a barn they’ve occupied to another location and unfamiliar stalls is cleaning and disinfecting before another horse can move in. Stalls are mucked daily and cleaned, but disinfecting is a must. Frequency, though, varies among trainers; some might disinfect weekly, others only monthly.  

At Keeneland, the maintenance team follows departed trainers and does a second disinfecting to ensure the next occupant gets a clean environment. “Our team will go in, and they’ll basically strip and clean (disinfect) all of the stalls,” said Brown. “They’ll be left for a period of time for desiccation (allowing stalls to dry out). 

“Getting those stalls tossed out and then having them air out and dry as well as being inspected becomes a part of any kind of biosecurity protocol.“ 

Trainers, with few exceptions, follow guidelines prescribed by the Equine Disease Communication Center to one degree or another. These include scrubbing surfaces with warm, soapy water to remove any traces of organic matter (basically anything that comes out of a horse); allowing the surface to dry; applying a disinfectant; allowing the surface to dry after the application of a disinfectant; and disinfecting crossties if in use. 

The choice of disinfectant is at the discretion of a trainer or attending veterinarian. Brown said his maintenance team uses products recommended by the USDA or other regulatory bodies that are specified for controlling the spread of potentially infectious pathogens.

He is investigating a new “delivery system” of a disinfectant from a firm in Nicholasville, Ky., just south of Lexington, produced by Atmosphere Supply. The firm supplies a foaming product for farms of all types that have applications (literally) for racetrack stalls.

Peter Healy, business development manager for the firm, authored a manual, titled Biosecurity for the Equine Industry, after Thoroughbred farm personnel sought help during the rotavirus B epidemic. Healy’s company was asked to assess and critique biosecurity protocols and other practices. “Everybody was in a panic with this new rotavirus back in 2020,” he said.

One key recommendation right off the bat from Healy was to not use bleach. “It is for hard (non-porous) surfaces, not for wood. It does absolutely nothing when applied to wood and could possibly be harmful to a horse.” 

Other disinfectants like hydrogen peroxide have the potential to be caustic or acidic and also hazardous. “Horses rubbing against a stall wall are going to come in contact with whatever has been applied,” Healy said.

One particular issue is the application of a disinfectant. Wiping down or spraying with a liquid in a dark stall means the possibility that coverage might be incomplete. A liquid will also run off quickly, according to Healy. The foam disinfectant produced by his company solves both problems and dries in only 10 minutes. Use or frequency of use is at a trainer’s discretion, but it could be applied daily. 

Healy also recommends any product containing hypochlorous acid, primarily a salt and water mixture, that can be sprayed daily even while a horse is in the stall, as ingestion will not harm them.

Other measures to battle pathogens or disease-producing agents are largely a matter of common-sense hygiene. Water buckets at the end of a shedrow that every horse passing by can drink from are asking for disease to spread.

“Equipment contacting a horse can also be a source for contamination,” said Brown. “I know two or three trainers that have started dipping chains and shank clips in a water-diluted Nolvasan solution.” Nolvasan is a readily available skin and wound cleanser. It helps prevent disease spread if a hotwalker is going from horse to horse with the same shank, according to Brown.

Pathogens are generally organic but can be carried by humans. Here, too, there are preventive measures. Farmer at Churchill Downs noted that some trainers there are having their help wear gloves at feed time as they mix feed and add supplements. “That’s a proactive approach. They recognize they don’t have control over barn help 24/7,” he said.

Is there a day when grooms and hotwalkers are wearing gloves all the time, or stalls with a “last disinfected” sheet with dates posted on each?  All who were questioned for this story can’t see it, but similar and more stringent measures are already in place in Europe. At some racetracks in France, each stall will have a plastic seal that someone must break to enter—a guarantee that a stall has been disinfected. 

Over there, stall bedding and cleaning are the responsibility of the racetrack generally as most horses are day shippers. Some trainers have traced ringworm to sanitizing agents used by racecourses. “We are not told what they are using; there’s no real regime. Biosecurity is everything; it’s so important,” said French trainer Ilka Gansera-Leveque.

Gloves, plastic seals, “last disinfected” sheets… Sound far-fetched for American racetracks? Who knows? But if the solution to pollution is dilution…