Equine Vaccines Marissa Kazeck

Core vs. Non-core Core: vaccines that every animal of that species should receive. Protect against the most dangerous diseases. – Tetanus, Eastern/Western Equine Encephalomyelitis, West Nile Virus, and Rabies Non-core: vaccines an animal should receive depending on its particular lifestyle. – Strangles

Tetanus Transmission: Tetanus can happen when a horses wound becomes infected with the bacterial spore of Clostridium tetani. The spores multiply and produce a powerful poison that affects the muscles. Clinical Signs: stiff legged gait, tail held stiffly, ears pricked forward, horse may fall Outcome: treatment is difficult, and often unsuccessful. Zoonotic potential: Tail held stiffly Stiff legged gait Ears pricked forward Paralysis of breathing muscles

Tetanus cont… Route given: intramuscularly (IM). Best spot for that is the side of the neck. Vaccine Schedule: – Adult previously vaccinated: Vaccinate annually. – Adult previously unvaccinated: Give a primary 2 dose series within a 4 to 6 week interval between doses. Then vaccinate annually. – Pregnant previously vaccinated: Vaccinated annually and 4 to 6 weeks before foaling. – Pregnant previously unvaccinated: Give a 2- dose primary series with a 4 to 6 week interval between doses. Revaccinated 4 to 6 weeks before foaling. – Foals of mares vaccinated: Give a primary 3 dose series beginning at 4 to 6 months of age. 4 to 6 week interval between first and second does, third dose should be given at 10 to 12 months of age. – Foals of mares unvaccinated: Give a primary 3 dose series beginning at 1 to 4 months of age with 4 week intervals between doses. – All horses should be vaccinated annually.

Eastern/Western Equine Encephalomyelitis Transmission: By mosquitoes, and sometimes other bloodsucking insects. Horse from wild birds or rodents. Clinic Signs: Altered mentation, impaired vision, wondering, head pressing, circling, inability to swallow, irregular gait, paresis and paralysis, convulsions, and death. Outcome: No specific therapy. Supportive care includes fluids for the horse (unable to drink), use of anti-inflammatory agents, and anticonvulsants. Good nursing care. Zoonotic potential: People may be infected. Should always be aware of the possibility of human infection and take precautions.

Eastern/Western Equine Encephalomyelitis cont… Route given: intramuscularly (IM). Best spot for that is the side of the neck. Vaccine Schedule: – Adults previously vaccinated: Annual revaccination (best in spring) – Adults previously unvaccinated: Give primary series of 2 doses with a 4 to 6 week interval between doses. Then annually. – Pregnant previously vaccinated: Vaccinated 4 to 6 weeks before foaling. – Pregnant previously unvaccinated: Give a 2 dose primary series with a 4 week interval between doses. Booster again 4 to 6 weeks before foaling. – Foals of vaccinated mares: Give a primary 3 dose series starting at 4 to 6 months of age, with a 4 to 6 week interval between the first and second dose. The third dose should be given at 10 to 12 months of age. – Foals of unvaccinated mares: Give a primary 3 dose series starting at 3 to 4 months of age, with a 4 week interval between first and second dose. The third dose should be given at 10 to 12 months of age. – All horses should be vaccinated annually.

West Nile Virus Transmission: Mosquitoes (they feed off wild birds). Clinical signs: Weakness/Paralysis of hind limbs, impaired vision, circling, wondering, convulsions, colic, change in behavior, and restlessness. Outcome: No specific treatment. Supportive care (IV fluids), death is possibility if not treated the correct way or fast enough action taken. Zoonotic Potential: People may get it from being bit from an infected mosquito (rare to happen). Veterinarians should take precautions with birds.

West Nile Virus cont… Route given: intramuscularly (IM). Best spot for that is the side of the neck Vaccine Schedule: – Adult previously vaccinated: Annual revaccination before threat of mosquitoes. – Adult previously unvaccinated: Give a primary 2 dose series with 4 to 6 week intervals between the doses. Then annually. – Pregnant previously vaccinated: Vaccinated 4 to 6 weeks before foaling. – Pregnant previously unvaccinated: Same as Adult previously vaccinated, then again 4 to 6 weeks before foaling. – Foals of vaccinated mares: Give a primary 3 dose series starting at 4 to 6 months of age with a 4 to 6 week interval between first and second dose. The third dose should be given at 10 to 12 months of age. – Foals of unvaccinated mares: Give a primary 3 dose series with a 30 day interval between first and second doses and a 60 day interval between second and third doses. – All horses should be vaccinated annually.

Rabies Transmission: Occurs through a bite of an infected animal (usually wildlife). Bites on horses occur mostly on the muzzle, face, and lower limbs. Clinical signs: Signs may vary between horse. Some possible signs include, depression, loss of appetite, excessive salivation, difficulty swallowing, lack of coordination, aggressive, colic, convulsions, and paralysis. Outcome: Death usually occurs within 3 to 5 days after clinic signs are noticed. Zoonotic potential: No documented cases of horse to human transmission, but it can happen. All precautions should be taken.

Rabies cont… Route given: intramuscularly (IM). Best spot for that is the side of the neck Vaccine schedule: – Adult previously vaccinated: Annual revaccination – Adult previously unvaccinated: Give a single primary dose. Revaccinate annually. – Pregnant previously vaccinated: Vaccinated 4 to 6 weeks before foaling. – Pregnant previously unvaccinated: Vaccinated 4 to 6 weeks before foaling. – Foals of vaccinated mares: Give a primary dose series. First dose given no earlier than 6 months of age. Second dose given 4 to 6 weeks later. – Foals of unvaccinated mares: First dose should be given at 3 to 4 months of age. – Vaccinated all horses annually.

References tm tm owners/rabies-in-horses/ owners/rabies-in-horses/