Biosecurity Beyond the Barn
WORDS: JACKIE BELLAMY-ZIONS INTERVIEWING: DR SCOTT WEESE
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 yard 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 authorised personnel can enter. Procedures at controlled access points such as hand sanitising 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 and hands are washed before and after each interaction. Strategically placed alcohol-based sanitisers 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 and 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 of 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 unauthorised persons at the entrance of any areas used for isolation or quarantine.
► 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 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 aerosolise 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 sanitiser 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 minimising 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, minimising 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 diarrhoea, 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.
The most frequently reported diseases in the Northern Hemisphere are:
• 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 horseboxs.
• 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.
• Eastern Equine Encephalitis (EEE): another virus transmitted by mosquitos. This virus is more commonplace in North America with no recently reported equine cases in Europe. Eighty to ninety percent of infected horses develop acute and fatal neurologic disease.
• 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 or the rest of their life but are usually euthanised.
• 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.
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 minimise 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 travelling and keeping vaccinations up to date. Being aware of disease prevalence using information from the EDCC (equinediseasecc.org) 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 horsebox or make sure the horsebox you have hired is always cleaned between loads is of paramount importance. If the horsebox 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 horse's travelling companions is just as important as the cleanliness of the horsebox. 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 have 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 horsebox.
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 away from home be sure to bring your own broom and shovel for cleaning your horsebox and pack a thermometer along with your tack and other equipment. Clean and disinfect your equipment when you get ready to leave your off-site location.
Upon returning to your stables, 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.
IMPROVING WINTER BIOSECURITY & AIR QUALITY IN EQUINE YARDS
WORDS: DR BERNARD STOFFEL
Effective biosecurity in equine facilities aims to reduce the introduction and spread of pathogens, dust, allergens, and environmental irritants. During the winter stabling period, these risks increase significantly. A horse inhales over 100,000 litres of air per day up to 200,000 with exercise, and colder months typically bring 20-60% higher levels of fine particles (EEA, 2023).
Reduced ventilation, increased humidity and elevated ammonia all contribute to airway stress, making horses more vulnerable to inflammation, coughing, RAO and even exercise-induced pulmonary haemorrhage (EIPH).
Conventional disinfectants such as quaternary ammonium compounds (QACs), chlorine solutions and hydrogen peroxide remain important for surface hygiene, but they do not address airborne irritants, which represent the primary exposure pathway in enclosed stables. Some disinfectants can also leave persistent residues after drying.
Current DEFRA and EU REACH Annex XVII guidance encourages minimising cumulative exposure to such residues in enclosed environments, especially where horses and yard staff spend extended time.
This has led many yards to explore air-active, residue-free approaches as a complement to normal cleaning.
Recent developments in supramolecular chemistry - specifically the use of cucurbiturils, a class of molecular inclusion compounds - offer a practical way to help manage stable air quality. These structures physically bind and neutralise airborne pollutants including dust allergens, fungal fragments, ammonia-related VOCS and odour molecules. Unlike conventional disinfectants, they do not rely on oxidative chemistry or harsh contact action.
After being sprayed into the air, the molecular cages remain active when they settle, continuing to bind deposited pollutants on surfaces such as numnahs (saddle pads), rugs, partitions, bedding and stable doors. This provides an extended window of benefit during the high-risk winter months.
KEY ADVANTAGES OF THIS APPROACH INCLUDE:
Air-active mode of action in the breathing zone
Continued activity after drying, binding allergens and odour compounds on surfaces
Non-corrosive and non-oxidising, with minimal residue
Safe for use in occupied stables, with no requirement to vacate animals or staff
Together with routine hygiene, these innovatio s represent a shift from purely kill-based methods towards holistic air-quality management supporting respiratory comfort and reducing environmental stress during the winter stabling period.
Combating contamination in the racing yard
By Melissa Volpi
There is so much more to the Clean Sport initiative than the FEI Prohibited Substances List. Building relationships with local feed suppliers and developing a code of practice with staff will ensure your racehorse has a clean and clear system.
Horseracing is an inclusive sport. It was this ‘spirit of the sport’ that the FEI (Federation Equestre Internationale) wanted to preserve when it formed the Clean Sport commission on the 9th October 2009 in Copenhagen, Denmark.
But what is ‘Clean Sport’ and why is it necessary? According to the FEI, Clean Sport is about being honest and being true. It’s about having integrity and not letting our lust for winning cloud our judgement and respect for rules and laws. It’s about aiming for success, but accepting failure if it cannot be won fairly. The FEI believe that doping is contrary to the spirit of the sport and it has put together an initiative to ensure the end of positive drug testing for horses and their human athletes. Clean Sport is about being aware of prohibited substances, to include banned substances and controlled medication. It’s about being vigilant in feed management, medication management and stable management.
“In terms of applying the clean sport principles to racing yards, trainers need to be vigilant as it is so easy for prohibited substances to sneak in,” says Kate Hore, senior nutritionist at NAF (Natural Animal Feeds). “An obvious example may be an owner or staff member having a cup of coffee (source of caffeine) and a chocolate bar (source of theobromine) in the feed room, which then creates a potential risk of contamination and then for a positive drug test. The best advice is to avoid eating or drinking in the feed room or stable.”
The British Equestrian Trade Association (BETA) set up a Naturally Occurring Prohibited Substances (NOPS) scheme in 2009 that identifies the main NOPS and their sources, as well as providing a list of approved feed suppliers (companies that have signed up to be audited under the schemes new codes). “The BETA NOPS scheme is the only one of its kind and has cooperation from all corners of the world,” says Hore. “Contamination by NOPS is easier than people think, morphine being a good example. White poppies are grown commercially to produce morphine and the poppy seeds can be blown from one field to another, into a field of oats for example, which could then create a contamination issue further down the processing chain.”
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Brexit - How high are the stakes?
By Lissa Oliver
When Britain submitted its notice to withdraw from the EU in March 2017, one of the biggest issues became border control and movement of horses, particularly between the EU Republic of Ireland and its bordering British Northern Ireland. A hard border between the adjoining counties of Ireland presents its own physical and political difficulties, but any restriction on the movement of horses between Ireland, Britain, and mainland Europe gives rise to problems that affect us all.
The uncertainty of border control also impacts on the safety of the national herd and disease control. The main principle of the Tripartite Agreement was to prevent the spread of disease and that, as Irish Horseracing Regulatory Board’s chief veterinary officer Dr Lynn Hillyer reminds us, is crucial and arguably the biggest issue when it comes to Brexit negotiations.
Dr Lynn Hillyer
Currently, 10,000 horses move freely between the UK and Ireland every year. Seven thousand horses move overland between the Republic of Ireland (EU) and Northern Ireland (GB); 5,100 horses move between Ireland and France, the majority using Britain as a land bridge; and 5,000 horses move between Britain and France, according to Horse Racing Ireland (HRI) figures. Such freedom of movement is dependent upon the Tripartite Agreement, which will no longer be valid after 30th March 2019.
The Tripartite Agreement simplified the travel of horses between France, Britain, and Ireland and reduced the cost of moving horses between the three countries, allowing racehorses to be shipped without pre-movement veterinary checks and certification, and without the requirement for isolation and quarantine periods at their destinations.
“It’s not just about movement, it’s the protection of the herd against disease, and it’s absolutely critical that’s protected,” warns Dr Hillyer, who has been working with her French counterparts in ensuring that safeguards are in place in advance of the end of the Tripartite Agreement. “There has been added pressure on us because of the enormity of movement involved.”
Adding to the difficulty in resolving issues has been the British government’s reluctance to commit to decisions and state definite demands. MEP Mairead McGuinness has been advocating on behalf of Ireland and warned in January at the Irish Thoroughbred Breeders Association (ITBA) National Symposium, “We hope when we sit down to negotiate, common sense will prevail, but the EU is not prepared to tweak its principles to accommodate the UK. If we cannot overcome our problems, there will be real difficulties for your industry.”
Fortunately, there has been a concerted team effort between all sectors of the thoroughbred industry in France and Ireland as they united to draw up a proposal to replace the Tripartite Agreement. Rather than sit back and wait, they decided to put together a draft for an improved alternative to the Agreement, the High Health Status (HHS) document for horses. “What is lovely is how the racing bodies and breeding associations have all pulled together, and that’s something that has come through the talks really strongly,” Dr Hillyer says.
Working with the Turf Club were HRI, the ITBA, Horse Sport Ireland – the representative body for the sport horse sector of show jumpers, dressage, and eventers – and France Galop. Paul Marie Gadot, head of the horses and control department at France Galop, explains, “The EU Commission draft doesn’t fulfil all our wishes as the breeding stock isn’t included in their proposal. A lot of work is still to be done. To be clear, we are working on an expedited movement system for high health horses.
“Currently, we are going to suggest a solution to the European Commission, which is working on the new legislation regarding movements of horses in the European Community and with the third countries. Actually, we are trying to address the modification of the European Law regarding horse movement, which isn’t linked to the Brexit negotiations. This way is more technical and also safer. I will be happy when a new system allowing easy horse movements will be in place.”
Both Dr Hillyer and Gadot have been happy with the level of awareness and support from their respective governments. “Our contacts in the Department of Environment, Food and Rural Affairs (DEFRA) have been fantastic and their response to our queries have come back by return,” says Dr Hillyer.
“The public information seminars here are probably less frequent than in Ireland,” agrees Gadot. “The preparatory work is done with the representatives of the equine industry, especially at racing and breeding levels, and we are in permanent contact with the hard core in charge of preparing the future of racing and breeding in Ireland and UK.
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Equine Herpesvirus-1 : An Elusive Target
By Neil Bryant
Infectious diseases are not uncommon in racehorses in training, breeding stock, and pleasure horses. Some of the more serious diseases can be financially devastating to the animal’s owners and to the equine industry on the whole. Viruses belonging to the herpesvirus family cause some of the most well characterized equine infectious diseases, and the most problematic of these is equine herpesvirus 1 (EHV-1; species Equid alphaherpesvirus 1). EHV-1 is ubiquitous in most horse populations in the world. It is responsible for major economic and welfare problems causing respiratory disease, neurological disease (mainly seen in adult horses), and abortion and neonatal foal death in pregnant mares.
This was most notably highlighted by the multiple abortion outbreak recorded in Hertfordshire, England, between February and April 2016 in fully vaccinated animals (http://www.aht.org.uk/cms-display/interim-report16-april2.html). Studies have determined that EHV-1 is a common cause of abortion. Occasional cases have also been linked to EHV-4 infection, but this is much rarer and doesn’t account for episodes of multiple abortion, as is seen occasionally with EHV-1.
The virus
EHV-1 was first isolated from an equine abortion in the U.S. in the 1930s. At the time of first isolation the vets weren’t sure what it was, but they knew it was infectious. Subsequent genetic analysis much later led to the classification of the virus in the genus Varicellovirus (family Herpesviridae), together with its close relatives equine herpesvirus 4 (EHV-4; species Equid alphaherpesvirus 4) and equine herpesvirus 8 (EHV-8; species Equid alphaherpesvirus 8). Interestingly it is grouped with, and is therefore genetically similar to, the human herpesvirus responsible for chickenpox, the Varicella Zoster virus. Initial infection of horses was thought to occur around weaning, when virus-neutralizing antibodies transferred to the foal from the mare’s colostrum had declined enough to make them susceptible to infection. However, virus has been isolated from foals as young as seven days old with high antibody levels but without any significant clinical signs. Immunity to re-infection after primary infection is relatively short-lived, lasting between three-six months, but it is rare for naturally infected mares to abort in consecutive pregnancies.