How to Prevent Contagious Diseases in Show Horses

How to Prevent Contagious Diseases in Show Horses

By Dr Duncan Houston

Show horses are social athletes, whether they like it or not.

Every time a horse travels to a competition, clinic, training day, sale, camp, or shared facility, they enter a temporary disease-sharing network. Different horses, different barns, different water sources, different handlers, different trailers, and plenty of stressed immune systems all mix in one place.

That does not mean you should never compete. It means biosecurity needs to be part of the show routine, just like packing tack, checking shoes, and remembering the horse that loads beautifully at home may suddenly become a giraffe in public.

The goal is simple: reduce exposure before the show, avoid obvious disease risks during the show, and protect the home barn after the horse returns.

Quick Answer

Show horses are at increased risk of contagious disease because events concentrate horses from different properties and create opportunities for spread through nose-to-nose contact, shared equipment, people, surfaces, water areas, stalls, and trailers. The best protection is a layered biosecurity plan: current vaccinations, no shared buckets or tack, no nose contact, temperature monitoring, clean equipment, isolation of sick horses, and a post-show separation period before returning to the home herd. A temperature above 101.5°F, cough, nasal discharge, swollen glands, diarrhoea, neurological signs, or sudden dullness should prompt isolation and veterinary advice. (Equine Disease Communication Center)

Why Are Show Horses Higher Risk?

A show environment is not just a competition venue. From a disease-control point of view, it is a mixing bowl.

Horses may be exposed through:

• Nose-to-nose contact

• Coughing horses in nearby stalls

• Shared airspace in barns

• Shared wash bays

• Shared water points

• Hitching rails

• Stall walls and doors

• Feed tubs and buckets

• Tack and grooming gear

• Human hands and clothing

• Boots and wheelbarrows

• Trailers

• Manure-contaminated areas

The Equine Disease Communication Center notes that equine events pose a significant disease-spread risk because of the concentration of horses and the ways horses interact with people, other horses, shared supplies, equipment, and surfaces such as universal water troughs or hitching posts. (Equine Disease Communication Center)

In practice, the biggest risk is rarely one dramatic event. It is the small casual exposures: one shared bucket, one friendly sniff, one borrowed brush, one handler patting five horses in a row, one horse coughing in the stabling aisle.

Biosecurity is about stopping those little shortcuts from becoming a whole-barn problem.

Which Diseases Are We Most Worried About at Shows?

Show biosecurity is not designed for one disease. It reduces risk across many contagious problems.

Common concerns include:

Disease	Main signs	Why it matters at shows
Equine influenza	Fever, harsh cough, nasal discharge, lethargy	Highly contagious respiratory virus that spreads quickly through groups
Equine herpesvirus	Fever, nasal discharge, lethargy, swollen limbs, abortion, neurological signs	Can spread through respiratory secretions, equipment, people, and carriers
Strangles	Fever, thick nasal discharge, swollen lymph nodes, abscesses	Highly infectious and can spread by direct contact or contaminated surfaces
Equine coronavirus	Fever, dullness, appetite loss, diarrhoea, colic signs	Spreads mainly through manure contamination
Salmonella and other diarrhoeal diseases	Fever, diarrhoea, dehydration, colic signs	Shared environments and manure contamination increase risk
Ringworm and skin infections	Circular hair loss, crusts, itch or irritation	Can spread through grooming gear, tack, rugs, and direct contact
Equine infectious anaemia	Fever, weakness, anaemia, weight loss, sometimes carrier state	Blood-borne disease with movement and testing implications in many regions

Equine influenza is described as highly contagious, with spread through airborne droplets from affected horses, and signs can include fever, lethargy, anorexia, muscle pain, cough, and nasal discharge. (Equine Disease Communication Center)

EHV-1 and EHV-4 most often cause respiratory disease, but EHV-1 can also cause abortion, neonatal death, and neurological disease known as equine herpesvirus myeloencephalopathy. EHV can spread through inhalation, direct contact, respiratory secretions, contaminated clothing, and equipment. (Equine Disease Communication Center)

Strangles is caused by Streptococcus equi and is highly infectious. It spreads through horse-to-horse contact and contaminated surfaces, with fever often appearing before swollen lymph nodes, nasal discharge, coughing, or difficulty swallowing. (Equine Disease Communication Center)

The key point is this: you cannot identify all infectious horses by looking at them from across the warm-up arena.

Some horses are early in disease. Some are recovering. Some are carriers. Some have mild signs that people explain away as “dust,” “travel,” or “just a cough.”

Vaccination Helps, But It Is Not a Force Field

Vaccination is one of the most important parts of show horse biosecurity, but it does not replace hygiene, quarantine, or common sense.

AAEP divides equine vaccines into core and risk-based categories. Core vaccines are recommended for most horses because of disease severity, public health relevance, regional risk, or broad patient benefit. Risk-based vaccines depend on the horse’s location, travel, exposure, age, use, and individual risk. (AAEP)

For show horses, your vet may discuss vaccines such as:

• Equine influenza

• EHV-1 and EHV-4

• Strangles

• Core regional vaccines

• Other risk-based vaccines depending on geography and event type

AAEP notes that horses at increased risk of influenza exposure may be revaccinated every 6 months, and some facilities or competitions may require influenza vaccination within the previous 6 months for entry. (AAEP)

For EHV, vaccination can help reduce respiratory disease signs and severity, but EDCC notes that there is currently no vaccine labelled to prevent the neurological form, EHM. (Equine Disease Communication Center)

That distinction matters. A vaccinated horse can still get sick. A vaccinated horse can still need isolation. A vaccinated horse with fever after a show should not be waved through the barn like a VIP guest.

Vaccination lowers risk. It does not remove risk.

Before the Show: What Should You Do?

Good show biosecurity starts before the horse leaves home.

Check vaccination status early

Do not vaccinate the day before travel unless your vet specifically advises it. Vaccines need time to stimulate immunity, and some horses may feel mildly flat after vaccination.

A practical approach is to review show-season vaccines with your vet several weeks before the season starts. This gives time to update vaccines, meet event requirements, and avoid last-minute panic.

Check event requirements

Before entering, check:

• Vaccination requirements

• Health declaration requirements

• EIA or Coggins requirements where relevant

• Certificate of Veterinary Inspection requirements where relevant

• Arrival and check-in rules

• Isolation policy at the venue

• What happens if a horse becomes sick on site

EDCC recommends that event managers consider entry health requirements such as a Certificate of Veterinary Inspection, a negative EIA test within 12 months, horse health declarations, temperature logs for 3 to 5 days before competition, and proof of vaccination based on risk assessment. Requirements vary by country, region, event, and governing body. (Equine Disease Communication Center)

Take temperatures before travel

For several days before leaving, record your horse’s rectal temperature once or twice daily.

Do not travel if your horse has:

• Fever

• Cough

• Nasal discharge

• Dullness

• Poor appetite

• Diarrhoea

• Swollen lymph nodes

• Unexplained limb swelling

• Recent exposure to a sick horse

The expensive mistake is travelling a “maybe fine” horse and turning one horse’s early infection into a showground biosecurity drama.

Pack your own gear

Bring:

• Feed buckets

• Water buckets

• Hay nets

• Grooming kit

• Halter and lead rope

• Thermometer

• Towels

• Disinfectant wipes

• Hand sanitiser

• Disposable gloves

• Muck fork if practical

• Water from home if your horse is fussy

• Separate gear for each horse where possible

Do not rely on borrowing gear at the event. Sharing tack and buckets is how diseases get a free upgrade to business class.

Clean the trailer

Before loading, clean and disinfect the trailer properly.

Remove manure, bedding, old feed, and dirt first. Then wash, rinse, dry where possible, and disinfect according to the product label. Disinfectants do not work properly through organic material.

During the Show: How Do You Reduce Exposure?

At the show, your goal is to keep your horse’s disease “bubble” as small and boring as possible.

Avoid nose-to-nose contact

Do not let your horse sniff, nuzzle, or touch other horses.

This includes:

• In the warm-up area

• At wash bays

• Along stable aisles

• At trailer parking

• While grazing

• While waiting for classes

• Over temporary fencing

A quick sniff may seem harmless. From a respiratory disease point of view, it can be enough contact to matter.

Do not share buckets

Never share:

• Water buckets

• Feed tubs

• Hay nets

• Drenching syringes

• Bits

• Grooming brushes

• Towels

• Nose rags

• Thermometers

Shared water sources are a common biosecurity weak point. Bring your own buckets and avoid communal troughs whenever possible.

Keep the stall area clean

If your horse is stabled on site:

• Remove old bedding if needed

• Clean obvious organic material

• Disinfect safe contact surfaces where practical

• Use your own buckets

• Keep feed covered

• Avoid placing hay directly on contaminated ground

• Keep your equipment contained and labelled

EDCC recommends that event facilities provide sanitation before and after competitions and discourage horse-to-horse contact through show information and signage. (Equine Disease Communication Center)

Limit human contact

Do not let every friendly stranger pat, feed, or kiss your horse.

Yes, your horse is gorgeous. Obviously. Still not a public petting zoo.

People can move pathogens between horses on their hands, clothing, and footwear. EDCC specifically notes that infectious diseases can spread through contact with fomites such as tack, stalls, trailers, grooming equipment, and through people moving pathogens on hands, clothing, or footwear. (Equine Disease Communication Center)

Monitor temperature and behaviour

At multi-day shows, check your horse daily, and ideally twice daily if the venue is high-risk or there are disease alerts.

Watch for:

• Fever

• Cough

• Nasal discharge

• Reduced appetite

• Dullness

• Swollen glands

• Diarrhoea

• Colic signs

• Limb swelling

• Neurological changes

If your horse develops a fever or signs of illness, stop competing and contact the event veterinarian or your own vet.

After the Show: The Part Owners Often Skip

The highest-risk moment is often after the event, when the horse looks fine and everyone relaxes.

This is when a horse can bring disease back to the home barn.

Separate returning horses

A practical minimum is to separate returning horses from the resident herd for at least 14 days, especially after shows, clinics, sales, busy barns, or mixed transport.

For higher-risk situations, 21 days is often safer, especially if:

• There was an infectious disease alert at the event

• Your horse had close contact with unknown horses

• Your horse shared transport

• Your horse stayed in busy event stabling

• Your property has pregnant mares, foals, seniors, or immunocompromised horses

• Your horse is returning from a veterinary hospital

• EHV or strangles exposure is possible

• Your barn cannot tolerate an outbreak

EDCC recommends keeping new and returning horses separate and monitored for at least 14 days. For EHV prevention, Merck notes that new horses or horses returning from other premises are often isolated for 21 days before mixing with resident horses, especially around pregnant mares. (Equine Disease Communication Center)

So the practical rule is: 14 days is a common minimum. 21 days is the safer high-risk plan.

Take temperatures twice daily

During the post-show separation period, record temperature morning and evening.

Also monitor:

• Appetite

• Water intake

• Manure

• Cough

• Nasal discharge

• Swollen lymph nodes

• Limb swelling

• Energy level

• Neurological signs

EDCC advises that temperatures above 101.5°F should be reported to a veterinarian, especially in a biosecurity context. (Equine Disease Communication Center)

Clean all travel gear

After returning:

• Empty and scrub buckets

• Wash hay nets

• Clean grooming gear

• Clean boots

• Disinfect trailer surfaces

• Wash rugs and towels if appropriate

• Clean tack that contacted saliva or nasal discharge

• Dispose of used bedding and manure carefully

Do not bring show gear straight back into the main barn and drop it beside everyone else’s equipment.

That is how your grooming kit becomes a tiny disease bus.

Risk Framework: How Worried Should You Be?

Low Risk

Low risk means your horse has returned from a small, well-managed event, had no close contact with unknown horses, has a normal temperature, is eating normally, has no cough or nasal discharge, and is bright and comfortable.

Action: Separate from the main herd for at least 14 days if practical, monitor daily, and clean travel gear before returning it to normal use.

Moderate Risk

Moderate risk includes multi-day shows, shared stabling, busy warm-up areas, shared wash bays, recent travel stress, mild clear nasal discharge, mild cough, or an event with many horses from different regions.

Action: Separate from the herd, take temperatures twice daily, avoid shared equipment, and contact your vet if signs persist, worsen, or fever appears.

High Risk

High risk includes fever, thick nasal discharge, coughing, swollen lymph nodes, diarrhoea, reduced appetite, dullness, known exposure to a sick horse, an event disease alert, or multiple horses from the same event becoming unwell.

Action: Isolate immediately and call your veterinarian. Testing, movement restrictions, and a formal biosecurity plan may be needed.

Critical Risk

Critical risk includes neurological signs, severe respiratory distress, inability to stand, severe diarrhoea, dehydration, colic signs with fever, suspected EHV neurological disease, suspected strangles outbreak, or multiple horses on the property developing fever after an event.

Action: Treat this as urgent. Stop horse movement, isolate affected horses, call your vet, and follow disease-control advice.

What Else Could Look Like a Contagious Disease?

Not every cough after a show is influenza, and not every runny nose is strangles. But you should still act carefully until contagious disease is ruled out.

Possible causes include:

• Dust exposure from stabling

• Poor ventilation

• Equine asthma

• Viral respiratory disease

• Equine influenza

• EHV

• Strangles

• Bacterial pneumonia

• Choke

• Dental or sinus disease

• Allergies

• Travel stress

• Dehydration

• Heat stress

• Diarrhoeal disease from feed or water change

• Salmonella or other infectious gut disease

• Equine coronavirus

• Stress-related appetite loss

• Musculoskeletal soreness from travel or competition

The clinical question is not just “does this horse have a cough?”

The better question is: does this horse have a cough plus fever, dullness, nasal discharge, exposure history, or other horses getting sick?

That is what changes the urgency.

When Is This an Emergency?

Call your veterinarian urgently if a show horse develops:

• Temperature above 101.5°F with dullness or other signs

• Fever after travel or competition

• Coughing with fever

• Thick yellow, green, bloody, or foul nasal discharge

• Swollen lymph nodes under the jaw or at the throatlatch

• Difficulty swallowing

• Laboured breathing

• Not eating

• Severe diarrhoea

• Colic signs

• Dehydration

• Abnormal gum colour

• Hindlimb weakness

• Incoordination

• Urine dribbling

• Loss of tail tone

• Collapse or inability to stand

• Abortion

• Multiple horses affected after the same event

EHV neurological disease can include incoordination, hind-end weakness, urine dribbling, reduced tail tone, recumbency, and, in severe cases, paralysis. Testing and quarantine are primary disease-control tools for EHV. (Equine Disease Communication Center)

If neurological signs appear, do not transport the horse unless your veterinarian or animal health authority specifically instructs you to. Movement can increase risk and expose more horses.

What Should You Do If Your Horse Gets Sick After a Show?

1. Isolate first

Do not wait for a diagnosis. Move the horse away from others if safe, or create an isolation zone around the current stall or paddock.

EDCC states that the first 30 minutes of a disease outbreak are critical and recommends immediate isolation of horses showing clinical signs. (Equine Disease Communication Center)

2. Stop horse movement

Do not send horses to shows, clinics, lessons, agistment, breeding farms, or other properties until your vet has assessed the situation.

3. Call your vet

Give your vet:

• Temperature

• Appetite

• Cough details

• Nasal discharge description

• Manure changes

• Recent travel history

• Show name and dates

• Stabling details

• Any known exposure

• Number of horses at home

• Number of horses showing signs

• Vaccination history

4. Use dedicated equipment

For the sick horse, separate:

• Halter and lead rope

• Buckets

• Feed tubs

• Thermometer

• Grooming gear

• Rugs

• Muck fork

• Wheelbarrow

• Towels

• Cleaning supplies

EDCC recommends isolating objects that contacted the sick horse, including tack, grooming brushes, stall-cleaning tools, buckets, feeders, and water troughs. (Equine Disease Communication Center)

5. Handle healthy horses first

If the same person must care for all horses, handle healthy horses first and the sick or exposed horse last. Then wash hands, change clothing where possible, and clean footwear.

6. Keep a health log

Record twice daily:

• Temperature

• Appetite

• Water intake

• Manure

• Cough

• Nasal discharge

• Lymph node swelling

• Limb swelling

• Behaviour

• Medications

• Any changes

This log is extremely useful for your vet and for identifying which horses may have been exposed.

Common Mistakes Show Horse Owners Make

Treating vaccination as complete protection

Vaccines reduce risk and severity for some diseases, but they do not replace biosecurity.

Letting horses touch noses

A quick greeting can be enough to spread respiratory pathogens.

Sharing water buckets

This is one of the easiest avoidable mistakes.

Borrowing grooming gear

Brushes, towels, and tack can carry saliva, mucus, skin organisms, and dirt from other horses.

Travelling a horse that is “just a bit off”

If your horse has a fever, cough, discharge, diarrhoea, poor appetite, or dullness, do not travel.

Skipping post-show separation

The horse may look normal while incubating disease. A few days of caution can save weeks of barn chaos.

Using the same thermometer for every horse

Rectal thermometers can spread infectious material if not cleaned properly. Use individual thermometers where possible.

Waiting for test results before isolating

Isolation starts when disease is suspected, not after the lab confirms it.

How to Build a Simple Show Biosecurity Plan

A good plan does not need to be fancy. It needs to be usable.

Before the show

• Review vaccines with your vet

• Check event requirements

• Take temperatures for 3 to 5 days before travel

• Pack individual gear

• Clean the trailer

• Do not travel sick horses

• Know the event vet contact if available

At the show

• Avoid nose contact

• Use your own buckets and gear

• Avoid communal water

• Limit stranger contact

• Monitor temperature and appetite

• Keep your horse’s area clean

• Report illness early

After the show

• Separate from resident horses

• Take temperatures twice daily

• Clean and disinfect gear

• Watch for cough, discharge, fever, diarrhoea, swollen glands, and dullness

• Call your vet if anything changes

• Do not return to normal turnout too quickly after high-risk exposure

For barns with multiple show horses

• Keep travel horses separate from non-travelling horses where possible

• Use labelled gear for each horse

• Keep a shared health log

• Set clear return-from-show rules

• Require owners to report fever or illness immediately

• Have an isolation area identified before it is needed

A biosecurity plan that only exists after the first horse spikes a fever is not a plan. It is a group project in panic.

Prevention Checklist for Show Horse Owners

Use this as the practical version:

• Keep vaccinations current with your vet

• Know event health requirements

• Take temperatures before and after travel

• Do not travel sick horses

• Bring your own buckets, feed, water, tack, and grooming gear

• Avoid nose-to-nose contact

• Avoid communal water

• Do not share equipment

• Limit people touching your horse

• Clean and disinfect the trailer

• Separate returning horses for 14 to 21 days depending on risk

• Isolate immediately if fever or clinical signs appear

• Call your vet early

• Keep records of travel, temperatures, vaccines, and symptoms

The best show biosecurity is boring, repetitive, and slightly annoying.

That is exactly why it works.

FAQs

How long should I isolate my horse after a show?

At least 14 days is a practical minimum for many returning show horses, especially if they mixed with unknown horses. Use 21 days for higher-risk situations, EHV concerns, hospital returns, known exposure, vulnerable home herds, or when your veterinarian recommends it. (Equine Disease Communication Center)

What temperature is concerning after a horse show?

A temperature above 101.5°F should be treated as concerning, especially after travel or exposure to other horses. Isolate the horse and call your veterinarian if fever appears with cough, nasal discharge, dullness, poor appetite, diarrhoea, swollen glands, or neurological signs. (Equine Disease Communication Center)

Can vaccinated show horses still get EHV or flu?

Yes. Vaccination can reduce risk, severity, and spread, but it does not guarantee complete protection. EDCC notes that there is no vaccine labelled to prevent the neurological form of EHV, and AAEP notes that high-risk horses may need influenza revaccination every 6 months depending on exposure and event requirements. (Equine Disease Communication Center)

Should I let people pet my horse at shows?

It is safer to limit contact. People can move pathogens between horses on hands, clothing, and footwear. This matters most during outbreaks, at busy events, and when people have recently handled other horses. (Equine Disease Communication Center)

What should I do if my horse starts coughing at a show?

Stop competing, take the temperature, separate the horse from others, and contact the event veterinarian or your own vet. Do not assume it is dust if there is fever, nasal discharge, dullness, or other horses becoming sick.

Final Thoughts

Show biosecurity is not about wrapping your horse in bubble wrap and never leaving home.

It is about making smart, consistent choices that reduce risk without ruining the joy of competing.

The big rules are simple: vaccinate appropriately, do not travel sick horses, avoid nose contact, never share buckets, bring your own gear, monitor temperatures, separate horses after travel, and isolate immediately if signs appear.

Most outbreaks do not start with someone doing something dramatic. They start with one small shortcut.

A shared bucket.
A quick sniff.
A horse that was “probably fine.”
A fever no one checked.
A returning show horse turned straight back out with the herd.

Biosecurity is how you stop one small shortcut from becoming a whole-yard problem.

---

If you are unsure whether your horse’s cough, fever, nasal discharge, swollen glands, show exposure, or post-travel behaviour needs isolation or veterinary testing, ASK A VET™ can help you decide what can be monitored, what needs a vet visit, and what should be treated as urgent.