Horse Vaccination Schedule: Core & Risk-Based Vaccines for 2026

Why Vaccination Is the Foundation of Equine Health Care

Every horse owner faces the same question each spring: which vaccines does my horse actually need? The answer depends on where you live, how your horse is used, and whether he ever comes into contact with other horses. But some vaccines are non-negotiable — the American Association of Equine Practitioners (AAEP) calls them core vaccines, and every horse in North America should receive them, every year, without exception.

Vaccines work by training the immune system to recognize and destroy pathogens before they can cause disease. When a horse is vaccinated, the immune system produces antibodies and memory cells. If the horse later encounters the real pathogen, the immune system responds rapidly — often before clinical disease can develop. This protection is not permanent; antibody levels decline over time, which is why annual (or more frequent) boosters are essential.

Beyond individual protection, vaccination contributes to herd immunity. When a high percentage of horses in a barn, show circuit, or geographic region are vaccinated, disease spread is slowed even for horses whose immunity has waned. This is why boarding facilities, competition venues, and breed associations increasingly require proof of current vaccinations.

The AAEP Vaccination Guidelines, last fully updated in 2021 with ongoing addenda, provide the scientific basis for equine vaccination programs in the United States and Canada. These guidelines are developed by veterinary specialists in infectious disease, internal medicine, and equine practice. Your veterinarian uses these guidelines — along with knowledge of local disease prevalence, your horse's history, and your management practices — to design a personalized vaccination program.

This guide walks through every vaccine the AAEP addresses, explains the diseases they prevent, and gives you the practical scheduling information you need to keep your horses protected in 2026.

CORE Vaccines: Required for Every Horse

The AAEP defines core vaccines as those that protect against diseases that are endemic, virulent, highly transmissible, a zoonotic risk, or required by law, and for which the consequences of infection are severe. These four vaccines are core for all horses in North America regardless of breed, age, use, or location.

1. Eastern and Western Equine Encephalomyelitis (EEE/WEE)

Equine encephalomyelitis is caused by mosquito-borne alphaviruses. The Eastern (EEE) and Western (WEE) strains are distinct viruses but are typically combined in a single multivalent vaccine. Both cause severe, often fatal inflammation of the brain and spinal cord.

The Disease

EEE is the more lethal of the two. Case fatality rates in horses reach 75–95% with EEE, and horses that survive are often left with permanent neurological deficits — blindness, behavioral changes, or an inability to swallow. The disease progresses rapidly: a horse can go from normal to moribund within 24–48 hours of showing the first signs. WEE has a lower fatality rate (20–40%) but is still a serious, life-threatening disease.

Clinical signs of both diseases are similar and reflect progressive brain inflammation:

• Fever (103–106°F) — often the first sign, sometimes missed
• Depression and loss of appetite
• Head pressing against a wall or fence
• Difficulty swallowing, "sleeper syndrome" posture (chin resting on fence)
• Circling, apparent blindness, loss of coordination
• Seizures and recumbency in severe cases

There is no specific antiviral treatment. Supportive care — anti-inflammatories (flunixin meglumine, dexamethasone), intravenous fluids, nutrition support, and intensive nursing — gives some horses a fighting chance, but the costs are enormous and the prognosis for EEE is grim.

Transmission

Both viruses are maintained in wild bird populations and transmitted to horses (and humans) by mosquitoes, primarily Culiseta melanura (EEE) and Culex tarsalis (WEE). Horses are dead-end hosts — they cannot transmit the virus to other horses or to people directly. But a sick horse in your pasture is a signal that infected mosquitoes are present.

Geographic Risk

EEE is most prevalent along the Atlantic Coast, Gulf Coast, and Great Lakes region. WEE is more common in the western United States and Canada. Both occur in the Midwest. Florida, Louisiana, and the Gulf States see EEE activity nearly every year. WEE outbreaks are less frequent but occur when conditions favor mosquito populations.

Vaccination Protocol

• Primary series (naive horses): Two doses 4–6 weeks apart
• Annual booster: Spring, 4–6 weeks before mosquito season begins
• High-risk areas (Gulf Coast, Florida): Semi-annual boosters (spring and fall) due to year-round mosquito activity
• Foals: Begin at 4–6 months of age; three-dose primary series
• Broodmares: Booster 4–6 weeks pre-foaling for optimal passive transfer via colostrum

The EEE/WEE vaccine is almost universally combined with tetanus and West Nile in a 4-way or 5-way product (e.g., Prestige 5 + WNV, Fluvac Innovator 6). This simplifies administration and reduces the number of injections your horse receives.

2. West Nile Virus (WNV)

West Nile Virus arrived in North America in 1999 and spread across the continent within four years. Today it is endemic in all 48 contiguous states and has caused thousands of equine deaths. Horses are significantly more susceptible than humans and suffer far more severe disease when infected.

The Disease

WNV causes West Nile encephalitis — inflammation of the brain — through a mechanism similar to EEE/WEE. Case fatality in horses is approximately 30–35%, lower than EEE but still significant. Roughly 40% of horses that survive have residual neurological deficits at one year post-infection.

Clinical signs include:

• Fever (often mild or absent initially)
• Weakness or stumbling in hindquarters (flaccid paresis)
• Ataxia — a characteristic "drunk" walking pattern
• Muscle fasciculations (twitching), particularly of the face and neck
• Hypersensitivity to touch and sound
• Difficulty rising, recumbency in severe cases
• Behavioral changes: hyperexcitability or profound depression

Treatment is supportive: NSAIDs, corticosteroids to reduce brain inflammation, fluid therapy, and careful nursing care. Some horses require sling support. Recovery can take weeks to months.

Geographic Risk in 2026

WNV activity is tracked weekly by the USDA and CDC. States with consistent year-over-year activity include California, Texas, Colorado, Nebraska, and the Mississippi Valley states. In 2025, significant equine cases were reported in Texas, Kansas, and the Gulf Coast region. Your veterinarian monitors CDC WNV activity maps to assess local risk.

Vaccination Protocol

• Primary series: Two doses 3–6 weeks apart
• Annual booster: Spring, before mosquito season
• High mosquito burden areas (SE US, irrigated western states): Semi-annual — spring and mid-summer
• Foals of vaccinated mares: Begin primary series at 4–6 months
• Foals of unvaccinated mares: Begin at 3–4 months; maternal antibody interference is less concern

Three conditionally or fully licensed WNV vaccines are available in the U.S.: a killed virus vaccine (Fort Dodge/Zoetis), a recombinant canarypox-vectored vaccine (Merial), and a DNA plasmid vaccine (West Nile-Innovator DNA, Zoetis). All three have demonstrated efficacy and safety. Your veterinarian may have a preference based on local efficacy data and your horse's specific situation.

3. Tetanus (Clostridium tetani)

Tetanus is caused by a potent neurotoxin produced by Clostridium tetani, an anaerobic bacterium found ubiquitously in soil and horse manure. Horses are the most susceptible domestic species to tetanus — far more so than cattle, dogs, or humans.

The Disease

The tetanus toxin (tetanospasmin) is one of the most potent biological toxins known. It blocks the release of inhibitory neurotransmitters in the spinal cord, causing uncontrolled, sustained muscle contractions. The classic "sawhorse" stance — stiff, rigid limbs, extended neck, flared nostrils — is pathognomonic for tetanus.

Clinical signs progress over 24–72 hours:

• Stiffness and difficulty moving — often mistaken for muscle soreness initially
• Third eyelid prolapse (the nictitating membrane flicks across the eye) — a hallmark sign
• Trismus (lockjaw) — inability to open the mouth, drooling
• Nostril flaring, erect ears, anxious expression
• Hypersensitivity to light, sound, and touch — any stimulus triggers violent spasms
• Spasms of the entire body, risking fractures and torn muscles
• Respiratory failure from laryngeal spasm in terminal cases

Case fatality in unvaccinated horses is 50–75%. Treatment involves massive doses of tetanus antitoxin, penicillin G to kill the bacteria, muscle relaxants (acepromazine, diazepam), and intensive nursing in a dark, quiet stall. Horses that survive require weeks of intensive care.

How Horses Get Tetanus

C. tetani spores are everywhere in the environment — in soil, wood, rust, and especially manure. Any wound — a nail puncture to the hoof sole, a wire cut on the leg, a surgical incision, a castration site — can introduce spores into anaerobic tissue where they germinate and produce toxin. Deep puncture wounds are highest risk because the lack of oxygen is ideal for bacterial growth.

Vaccination Protocol

• Annual booster: Any time of year; often combined with EEE/WEE and WNV in spring
• After any wound or surgery: Booster if more than 6 months since last vaccination; tetanus antitoxin (TAT) if unvaccinated or vaccination history unknown
• Castration: Always verify tetanus vaccination status before the procedure
• Primary series: Two doses 4–6 weeks apart for naive horses
• Foals: Begin at 4–6 months; three doses at 4–6 week intervals
• Broodmares: Booster 4–6 weeks pre-foaling to maximize IgG in colostrum

Tetanus toxoid provides excellent, long-lasting immunity. A well-vaccinated horse has strong protection, but the annual booster is important because tetanus exposure risk never goes away — horses live in environments loaded with C. tetani spores.

4. Rabies

Rabies may seem like a low-probability concern for horses — equine cases are uncommon in most years — but the AAEP classifies it as a core vaccine for three compelling reasons: the disease is invariably fatal, it is transmissible to humans (a major zoonotic risk), and there is an effective, safe vaccine available.

The Disease

Rabies virus infects the central nervous system and causes progressive, fatal encephalitis. There is no treatment once clinical signs appear. Horses can present with either the "furious" form (aggression, self-mutilation, hyperexcitability) or the "dumb" form (progressive paralysis, depression, inability to swallow). Both forms are fatal within 3–10 days of clinical signs.

Horses with suspected rabies represent a serious human health risk. Veterinarians, farm workers, and owners who have had mucous membrane or wound exposure to a rabid horse's saliva may require post-exposure prophylaxis (PEP) — an expensive and disruptive series of injections. A vaccinated horse provides peace of mind for everyone who handles it.

Transmission

Wildlife reservoirs vary by region: raccoons (Southeast and Mid-Atlantic), skunks (Midwest and Great Plains), foxes (Southeast and Texas), bats (nationwide), and coyotes (Texas-Mexico border). Horses are infected when bitten by a rabid animal — often while grazing at dusk or dawn when bats and skunks are active. Pasture horses in areas with high wildlife rabies prevalence are at greatest risk.

Vaccination Protocol

• Annual booster: Any time of year (often combined with spring vaccines)
• Primary series: Single dose for horses over 3 months of age; booster one year later, then annually
• Foals: Begin at 6 months of age

Two killed-virus equine rabies vaccines are licensed in the U.S. (IMRAB 3 and Rabvac 3). Both are safe and effective. Some states have specific requirements about who can administer rabies vaccines to horses — check with your veterinarian about local regulations.

RISK-BASED Vaccines: Tailored to Your Horse's Exposure

Risk-based vaccines are recommended when a horse's lifestyle, location, or management creates specific exposure risks. Your equine veterinarian is your best guide to which risk-based vaccines make sense for your horses. The following vaccines have solid evidence of efficacy and are commonly used.

Equine Influenza

Equine influenza (EI) is caused by influenza A viruses, subtype H3N8. It spreads through respiratory droplets and aerosolized secretions — highly contagious in any situation where horses congregate. Think shows, sales, trail rides, boarding facilities, and race tracks.

The Disease

Equine influenza causes acute respiratory disease: high fever (up to 106°F), a harsh dry cough, nasal discharge, and profound depression. Most horses recover fully in 2–3 weeks with rest, but secondary bacterial pneumonia is a serious complication. In performance horses, the 3-week recovery rule — one week rest for each day of fever — can mean 6 weeks or more off work.

The 2003 Dubai outbreak and 2007 Australian outbreak (in a previously naive population) demonstrated how rapidly EI spreads and how economically devastating it can be in unvaccinated populations.

Vaccination Protocol

• Performance/show horses with high exposure: Every 6 months; some showing horses vaccinated every 3–4 months during competition season
• Backyard/trail horses with low exposure: Annually
• Primary series: Two doses 4–6 weeks apart
• Intranasal modified live vaccine (FluAvert I.N.): Single dose; provides mucosal immunity; excellent for horses that will receive the injectable annually

Vaccine strain matching matters with EI, just as with human flu vaccines. The USDA monitors circulating strains and recommends updates to vaccine manufacturers when significant antigenic drift is detected. The 2026 AAEP guidelines reflect the most current strain recommendations.

Equine Herpesvirus (EHV-1 and EHV-4)

Equine herpesviruses are among the most common and economically significant pathogens in horse populations. EHV-1 and EHV-4 are distinct but related viruses that cause respiratory disease; EHV-1 also causes neurological disease and abortion.

EHV-4: Rhinopneumonitis

EHV-4 primarily causes upper respiratory disease ("rhino") — fever, nasal discharge, cough — indistinguishable clinically from equine influenza. It spreads readily at shows and in boarding barns. Young horses are most susceptible. The EHV-4 vaccine reduces clinical signs and viral shedding but does not prevent infection entirely.

EHV-1: Abortion and Neurological Disease

EHV-1 is more concerning for two specific populations:

1. Pregnant mares: EHV-1 can cause abortion storms — sudden, simultaneous abortions in multiple mares in a herd — typically at 7–11 months of gestation. The aborted foal and placenta contain high concentrations of virus and are highly infectious to other mares. A single introduction of EHV-1 into an unvaccinated pregnant mare population can be catastrophic.
2. Neurological EHV-1 (EHM): Some strains of EHV-1 (particularly those with the D752 neuropathogenic mutation) cause equine herpesviral myeloencephalopathy (EHM). Affected horses develop hindlimb incoordination, urinary incontinence, and recumbency. Case fatality in severe EHM approaches 30–50%. EHM outbreaks at shows and training facilities have prompted strict biosecurity protocols.

Important limitation: Current EHV vaccines are not labeled for prevention of neurological disease (EHM). They reduce viral replication and shedding but do not reliably prevent EHM in exposed horses. Despite this limitation, vaccination is still recommended for general EHV-1/4 respiratory and reproductive protection.

Vaccination Protocol

• Performance/show/boarding horses: Every 6 months for respiratory protection
• Pregnant mares: At months 5, 7, and 9 of gestation with Pneumabort-K or Prodigy (specifically labeled for abortion prevention); booster at 4–6 weeks pre-foaling for respiratory strains
• High-risk facilities or during outbreaks: Some veterinarians use 3-month intervals
• Primary series: Two doses 4–6 weeks apart

Strangles (Streptococcus equi subsp. equi)

Strangles is the most commonly diagnosed equine infectious disease in the world. Caused by the gram-positive bacterium Streptococcus equi, it spreads through direct contact with infected horses or contaminated fomites (buckets, brushes, hands). It earned its dramatic name from the swollen lymph nodes under the jaw and throat that can enlarge to the point of obstructing the airway.

The Disease

Classic strangles causes fever, depression, thick purulent nasal discharge, and dramatic swelling and abscessation of the submandibular and retropharyngeal lymph nodes. Abscesses rupture spontaneously (or are surgically lanced) after 1–2 weeks. Most horses recover, but the disease causes significant morbidity, requires prolonged isolation, and can persist in a barn for months if carrier horses are not identified.

Complications include bastard strangles (internal abscess formation), purpura hemorrhagica (immune-mediated vasculitis), and guttural pouch empyema (bacterial colonization of the guttural pouches creating a long-term carrier state).

Two Vaccine Types Available

Two fundamentally different vaccine technologies are available for strangles in the U.S.:

1. Intramuscular killed vaccine (Strepvax II, Zoetis): Contains killed S. equi extract. Requires 2-dose primary series. Associated with local injection site reactions — firm swellings are common, and rare cases of injection site abscess or purpura hemorrhagica have been reported in horses with high SeM antibody titers. The AAEP recommends SeM titer testing before administering IM strangles vaccine to horses with unknown recent exposure history.
2. Intranasal modified live vaccine (Pinnacle I.N., Boehringer Ingelheim): Contains a live attenuated strain of S. equi. Stimulates mucosal IgA immunity at the site of natural infection. More physiologically relevant than IM vaccination. Administered as drops into one nostril. Contraindicated in immunocompromised horses.

Vaccination Protocol

• High-risk facilities (boarding barns, show barns, rescue facilities): Annual or semi-annual intranasal vaccination
• Low-risk (isolated backyard horses with no new introductions): Vaccination may not be necessary; discuss with your vet
• Before vaccination: Check SeM titer if IM vaccine is being used and horse has unknown recent strangles exposure
• Never vaccinate during an active outbreak

Potomac Horse Fever (Equine Monocytic Ehrlichiosis)

Potomac Horse Fever (PHF) is caused by Neorickettsia risticii, an intracellular organism transmitted by ingestion of aquatic insects (mayflies, caddisflies, damselflies) infected with the parasite. Horses in river valleys, near streams, ponds, and irrigated pastures are at highest risk, particularly in late summer and fall.

PHF causes fever, depression, anorexia, and profuse watery diarrhea. Laminitis is a serious complication occurring in 30–40% of clinical cases. Case fatality without treatment is 30%; with aggressive treatment (oxytetracycline) started early, most horses recover.

Vaccination Protocol

• Geographic risk areas: Annual booster in spring; semi-annual (spring and summer) in highest-risk river valley locations
• Non-endemic areas: Not routinely recommended
• Efficacy note: PHF vaccine efficacy is modest (~50–60%) due to antigenic variation among strains. Vaccination reduces severity but does not reliably prevent infection.

Botulism (Clostridium botulinum)

Botulism is caused by toxins produced by Clostridium botulinum. Horses encounter botulinum toxin through ingesting preformed toxin in spoiled feed, ingesting spores that produce toxin in the GI tract, or through wound infection. Botulinum toxin blocks neuromuscular transmission, causing progressive flaccid paralysis.

Clinical signs include dysphagia (difficulty swallowing — feed falls from the mouth), muscle weakness, and "shaker foal syndrome" in foals under 4 weeks (generalized trembling, inability to stand, death if untreated). Treatment with polyvalent botulinum antitoxin can be life-saving but is extremely expensive.

Vaccination Protocol

• Endemic areas (mid-Atlantic breeding farms): Annual booster; 3-dose primary series over 4 weeks for naive horses
• Broodmares in endemic areas: Booster 4–6 weeks pre-foaling
• Facilities feeding haylage or silage: Vaccination strongly recommended regardless of region

Anthrax, VEE, Rotavirus, and Leptospirosis

Anthrax: Annual vaccination in endemic geographic hotspots (west Texas, Oklahoma panhandle, South Dakota badlands, parts of Montana and Minnesota). Requires a veterinarian for administration.

Venezuelan Equine Encephalomyelitis (VEE): Included in some multivalent vaccines. Appropriate for horses in border states (Texas, New Mexico, Arizona, California) and for horses traveling to Central or South America.

Rotavirus: For pregnant mares on large breeding farms with recurring foal diarrhea problems. Primary series: 3 doses at 8, 4, and 2 weeks before foaling. Annual booster 4 weeks before foaling in subsequent years. Protects foals through colostral IgA and IgG.

Leptospirosis: Horses most commonly develop recurrent uveitis (moon blindness) from Leptospira interrogans Pomona serovar infection. A conditionally licensed equine leptospirosis vaccine (Lepto EQ Innovator, Zoetis) is available. Recommended for horses with uveitis history, mares that have aborted due to leptospirosis, and horses with high cattle/wildlife exposure to contaminated water.

Complete Horse Vaccination Schedule by Horse Type

Foals (Born to Vaccinated Mares)

Foals receive maternal antibodies (passive immunity) through colostrum. These maternal antibodies protect the foal for the first months of life but also interfere with vaccine response — the foal's immune system cannot mount a full response to a vaccine antigen that is being neutralized by maternal antibody. This is called maternal antibody interference. The window for active vaccination typically opens at 4–6 months of age.

Adult Horses (Annual Maintenance)

Broodmares — The Critical Vaccination Program

Broodmares require a carefully timed vaccination program that serves two purposes: protecting the mare herself and maximizing the concentration of protective antibodies (IgG) in her colostrum, which will be the foal's only immune protection for its first months of life.

The pre-foaling booster is critical. Antibody concentrations in colostrum peak 2–4 weeks after vaccination and decline rapidly. Timing the booster 4–6 weeks before the expected foaling date maximizes the passive protection the foal receives when it nurses within the first 2–6 hours of birth.

Performance and Show Horses

USEF Requirements (2026): The United States Equestrian Federation currently requires documentation of influenza and rhinopneumonitis (EHV) vaccination within 6 months for horses competing at USEF-rated shows. Keep your vaccination records current and carry copies when traveling.

Vaccine Reactions: What to Watch For

Normal, Expected Reactions (no treatment needed)

• Local swelling at injection site: A firm lump 2–5 cm in diameter is normal and usually resolves within 1–2 weeks. Gentle massage immediately after injection can reduce swelling.
• Mild soreness: The horse may be reluctant to have the injection site touched for a day or two.
• Low-grade fever (up to 102.5°F): A modest temperature elevation for 12–24 hours post-vaccination is a sign of immune activation. Call your vet if fever exceeds 103°F or persists more than 24 hours.
• Mild depression and reduced appetite: Some horses feel "off" for 12–24 hours after vaccination.

Concerning Reactions (call your veterinarian)

• High fever (>103°F); swelling that grows rapidly, becomes warm, painful, or fluctuant
• Urticaria (hives) — raised wheals across the neck, shoulders, or body
• Lameness related to the injection site
• Muscle stiffness or ataxia

Anaphylaxis (Emergency — call immediately)

Anaphylaxis occurs within minutes of vaccination. Signs include extreme agitation, sweating, trembling, rapid heart rate, labored breathing, facial swelling, pale mucous membranes, and collapse. Epinephrine is the emergency treatment. This is why the AAEP recommends waiting 30 minutes after vaccination before leaving the barn when administering multiple vaccines simultaneously.

Vaccine Storage and Handling

• Temperature: Store at 2–7°C (35–45°F) — standard refrigerator temperature. Never freeze killed vaccines. Keep modified live vaccines at the same temperature and use promptly after reconstitution.
• Light: Store in original box or dark container — light degrades certain components.
• Transport: Use a cooler with ice packs (not in direct contact with vials) when transporting.
• Expiration dates: Never use expired vaccines.
• One needle per horse: Always use a new, sterile needle for each injection.
• Use within 1 hour of opening: Once opened or reconstituted, use promptly and discard unused portions.

The VCPR and Prescription Vaccines

A Veterinarian-Client-Patient Relationship (VCPR) is legally required before a veterinarian can prescribe prescription medications or prescription vaccines. Some equine vaccines are prescription-only (particularly rabies in some states). Even when vaccines are legally available over the counter, administering them without veterinary guidance means you may miss important risks — such as vaccinating a horse with high strangles SeM antibody titers with an IM strangles vaccine, or vaccinating a horse that is already incubating disease.

Find an equine veterinarian near you to establish a VCPR and develop a personalized vaccination program.

The Annual Wellness Exam: More Than Just Shots

The annual wellness exam is the cornerstone of preventive equine health care, not just a vaccination appointment. A comprehensive annual exam includes:

• Physical examination: Temperature, pulse, respiration; auscultation of heart, lungs, and GI sounds; palpation of lymph nodes; examination of eyes, skin, and musculoskeletal system
• Dental examination and floating: Horses' teeth grow continuously (hypsodont) and develop sharp points, hooks, and waves that interfere with chewing and cause pain. Annual floating of sharp points is essential.
• Coggins test (EIA testing): A blood test required annually in most states for horses used in competition, transported interstate, or sold. Required by virtually every horse show, trail ride organization, and boarding facility.
• Fecal egg count (FEC): Targeted deworming based on actual parasite egg counts has replaced calendar-based deworming programs. A fecal egg count tells you which horses have high strongyle burdens and actually need deworming.
• Body condition scoring: Systematic assessment of fat cover using the Henneke scale (1–9). Identifying trends early prevents both obesity (Equine Metabolic Syndrome, laminitis risk) and underconditioning.

Coggins Test: EIA Testing Requirements

Equine Infectious Anemia (EIA) is caused by a lentivirus transmitted by large biting flies. There is no vaccine and no treatment. Infected horses are permanently infected. A positive Coggins test result requires immediate quarantine and either permanent quarantine (at least 200 meters from other horses for life) or euthanasia.

When Coggins Testing Is Required

• Interstate transport (negative Coggins within 6–12 months required for health certificate)
• Entry to horse shows, rodeos, trail rides, polo matches, racing events
• Entry to boarding facilities
• Sale of horses

A negative Coggins test certificate should travel with your horse anytime it leaves your property.

Record Keeping: Your Horse's Vaccination History

Accurate vaccination records are essential for compliance with show and boarding requirements, providing your veterinarian with accurate history, avoiding dangerous vaccination of recently exposed horses, documenting tetanus vaccination status in wound emergencies, and interstate travel requirements.

What to Record

• Date of vaccination
• Vaccine product name and manufacturer
• Lot number and expiration date (required for traceability)
• Route of administration and injection site
• Dose number (first or second of primary series, annual booster)
• Administering veterinarian's name and signature

Working With Your Equine Vet: Building the Right Program

No online guide — including this one — can replace the personalized advice of an equine veterinarian who knows your horses, your farm, and your local disease risks.

Questions to ask at your annual wellness visit:

• Which vaccines do you recommend for my horse this year based on local disease activity?
• Have there been any equine disease outbreaks in our area recently?
• My horse attends shows regularly — does that change your recommendations?
• My mare is being bred this year — what is your recommended vaccination program?
• I'm moving my horse to a different region — what additional vaccines might be needed?

Find an equine veterinarian in your area using FarmVetGuide's directory of large animal and equine practices across all 50 states. For after-hours emergencies involving neurological symptoms or signs of encephalitis, use our emergency large animal vet finder immediately.

Frequently Asked Questions

Q: Can I give my horse's vaccines myself to save money?

A: Many equine vaccines are available over the counter and can legally be administered by the horse owner. However, there are real risks to self-vaccination: you may vaccinate a horse that is already incubating disease (which can worsen illness), use the wrong product for your horse's specific needs, store or administer vaccines incorrectly, and miss the broader wellness exam that your annual veterinary visit should include. The cost of annual vaccination through a veterinarian is modest compared to the cost of a preventable disease. At minimum, rabies vaccination should be handled by a veterinarian in most states, and strangles IM vaccine requires SeM titer assessment before administration. If budget is a concern, discuss scheduling options with your vet — some practices offer vaccine clinics at reduced cost.

Q: My horse is 25 years old and has been vaccinated his whole life. Does he still need annual vaccines?

A: Yes. Older horses are actually more susceptible to infectious diseases because immune function declines with age (immunosenescence). Senior horses may not mount as robust a response to vaccination, which is why some veterinarians recommend measuring antibody titers in senior horses after vaccination and giving boosters more frequently if titers are low. Continue annual core vaccination, and discuss with your veterinarian whether any risk-based vaccines should be added or removed based on his current lifestyle and health status.

Q: My horse had a big lump after his last flu vaccine — should I skip it next time?

A: Not necessarily. Injection site reactions — firm swellings — are common with certain adjuvanted vaccines, particularly strangles and some influenza products. Discuss the reaction with your veterinarian. Your vet may recommend switching to a different influenza vaccine product (there are multiple options with different adjuvant systems), pre-treating with an NSAID before vaccination, rotating to a different injection site, or using an intranasal influenza vaccine instead. Skipping influenza vaccination entirely is generally not recommended for horses with regular exposure to other horses.

Q: I just bought a horse with no vaccination history. What should I do?

A: Treat the horse as completely unvaccinated. Schedule a veterinary exam promptly and begin a full primary vaccination series for all core vaccines — EEE/WEE, WNV, Tetanus, and Rabies. Primary series for most vaccines requires two doses 4–6 weeks apart. For Tetanus, if the horse has a wound or undergoes surgery before completing the primary series, your veterinarian may also administer tetanus antitoxin (TAT) for immediate passive protection. Keep the new horse isolated from your other horses for the first 2–3 weeks while you assess its health status.

Q: Does my horse need a rabies vaccine if he never leaves the property?

A: Yes. Rabies virus comes to the horse — the horse does not need to leave the property to be exposed. Wildlife (bats, raccoons, skunks, foxes) do not respect fence lines. Any horse with access to the outdoors can be bitten by a rabid animal at dusk or dawn. Additionally, if your unvaccinated horse were to develop unusual neurological signs, it would be placed on a 6-month quarantine (in most states) or euthanized for rabies testing, because an unvaccinated horse with neurological signs cannot be distinguished from a rabid horse without a brain tissue examination. The rabies vaccine is inexpensive and the protection is complete — it is one of the clearest risk-benefit decisions in equine medicine.