Vaccination and Deworming Schedule for Horses: A Complete Guide

Maintaining your horse’s health goes beyond grooming, feeding, and exercise. A consistent vaccination and deworming schedule is essential for protecting your horse from potentially life-threatening diseases and internal parasites. Whether you are caring for a performance horse, a retired companion, or a young foal, understanding the correct timing and type of vaccines and dewormers is crucial.

In this guide, we will cover the core and risk-based vaccines, a general deworming schedule, and practical tips to help you stay on top of your horse’s healthcare routine.

Why Are Vaccinations and Deworming Important?

Vaccinations help build your horse’s immunity against infectious diseases. Vaccinating your horse safeguards their health and also helps prevent the spread of diseases to other horses. Deworming, on the other hand, controls internal parasites that can cause weight loss, poor coat condition, colic, and even death if left untreated.

By following a consistent schedule, you help ensure your horse stays healthy, active, and able to perform at their best.

Core Vaccinations for Horses

Core vaccines are recommended for all horses, regardless of age, breed, or location. These vaccines protect against diseases with a high fatality rate and are endorsed by the American Association of Equine Practitioners (AAEP).

1. Tetanus

• Type: Core
  
  

• Frequency: Annually
  
  

• Initial dose: between 4 to 6 months of age.
  
  

• Booster: 4 to 6 weeks after the first dose, then once a year
  
  

Tetanus is caused by bacteria that produce toxins commonly found in soil and manure. Even a small wound can expose your horse to this deadly disease.

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

• Type: Core
  
  

• Frequency: Annually, typically in spring
  
  

• First Dose: between 4 and 6 months old.
  
  

• Booster: After 4 to 6 weeks, then annually
  
  

EEE and WEE are transmitted by mosquitoes and can cause severe neurological damage in horses, often leading to death.

3. West Nile Virus (WNV)

• Type: Core
  
  

• Frequency: Annually
  
  

• First Dose: At 4 to 6 months
  
  

• Booster: 4 to 6 weeks later, then yearly
  
  

West Nile Virus is also spread by mosquitoes and may lead to serious neurological issues in horses.

4. Rabies

• Type: Core
  
  

• Frequency: Annually
  
  

• First Dose: At 4 to 6 months
  
  

• Booster: One dose, then annually
  
  

Rabies is fatal and poses a risk to humans as well. Vaccinating against rabies is both a health and legal necessity in many areas.

Risk-Based Vaccines

These are recommended based on your horse's location, travel schedule, age, and exposure risk. Discuss these with your veterinarian to determine which are appropriate for your horse.

1. Equine Influenza

• Type: Risk-based
  
  

• Frequency: Semi-annually for high-risk horses
  
  

• Ideal for: Horses that travel, compete, or are exposed to others
  
  

2. Equine Herpesvirus (EHV or Rhinopneumonitis)

• Type: Risk-based
  
  

• Frequency: Every 6 months for traveling or breeding horses
  
  

• Protects against: Respiratory disease, abortion in pregnant mares, and neurologic issues
  
  

3. Strangles

• Type: Risk-based
  
  

• Frequency: Annually or as recommended
  
  

• Ideal for: Horses in boarding or show environments
  
  

Other risk-based vaccines include Potomac horse fever, botulism, anthrax, and rotavirus. Your veterinarian can guide you on which ones are necessary for your region and horse's lifestyle.

Vaccination Schedule by Age

Foals

• 4-6 months: Begin core vaccines (tetanus, EEE/WEE, WNV, rabies)
  
  

• Booster: 4-6 weeks later
  
  

• Additional boosters: At 10-12 months of age
  
  

Yearlings

• Annually: Continue with core vaccines
  
  

• Risk-based: As needed based on activity and exposure
  
  

Adult Horses

• Annually: Core vaccines
  
  

• Risk-based: Recommended every 6 months, depending on your veterinarian's guidance.
  
  

Pregnant Mares

• EHV-1 vaccinations are recommended at the 5th, 7th, and 9th months of a mare’s pregnancy.
  
  

• Give booster vaccines for tetanus, EEE/WEE, WNV, and influenza 4 to 6 weeks prior to foaling to support the transfer of immunity to the foal through the mare’s antibodies.

Deworming Schedule for Horses

Parasite control is not one-size-fits-all. As resistance to dewormers becomes more common, rotating dewormers without a targeted strategy is no longer effective or recommended. Instead, focus on strategic deworming based on fecal egg counts (FECs) and veterinary guidance.

Key Internal Parasites

• Strongyles (large and small)
  
  

• Ascarids (primarily in foals)
  
  

• Tapeworms
  
  

• Pinworms
  
  

• Bots
  
  

General Deworming Schedule

Foals

• Start: At 2-3 months of age
  
  

• Repeat: Every 2 months until 1 year of age
  
  

• Rotate: Between dewormers (e.g., fenbendazole, ivermectin, pyrantel)
  
  

Yearlings and Two-Year-Olds

• Deworm: Every 3-4 months
  
  

• Include: Tapeworm treatment at least once yearly with praziquantel
  
  

Adult Horses (Over 3 Years)

• FEC-Based Deworming: Conduct fecal egg counts 1-2 times a year
  
  

• Low Shedders: Deworm 1-2 times a year
  
  

• High Shedders: Deworm 3-4 times a year
  
  

• Tapeworms: Treat once or twice annually
  
  

Strategic Deworming Tips

• Perform fecal egg counts to determine individual needs
  
  

• Avoid overuse of the same dewormer
  
  

• Clean paddocks and stables regularly
  
  

• Avoid overcrowding to limit parasite spread
  
  

Final Thoughts

A well-planned vaccination and deworming schedule is vital for your horse’s long-term health. By understanding which vaccines are core and which are risk-based, you can work with your veterinarian to create a personalized plan. Regular fecal egg counts, combined with strategic deworming, can prevent parasite resistance and keep your horse in top condition.

Whether you are caring for a competitive show horse or a pasture companion, maintaining a proactive health schedule ensures peace of mind and a happier, healthier horse. Be sure to keep accurate records of all vaccinations and deworming treatments and consult with your veterinarian for annual updates and regional disease trends.