Horses just like the rest of us on two feet require protection from a number of different bugs and viruses. This need becomes two fold with just how abundant their their time outside is and further reinforces the necessity of getting your horses vaccinated. There are as many as up to 9 vaccines horses may require. In this article I will highlight the top 5 vaccines horses should obtain as well as their key differences between foals, broodmare horses, and adult horses.
Top 5 Serious Illnesses to Vaccinate Against
There are 5 serious illnesses specifically in horses that if left not vaccinated, are almost impossible to prevent and result in extremely high mortality rates.
Tetanus
Tetanus is a very serious neurotoxin produced by Clostridium tetani that is commonly found living in soil and feces. Horses usually contract this bug from coming into contact with rusty objects where the bacteria may grow. Open cuts, scrapes, or surgical incisions are usually the precursor to infection. Once within the body of the horse, spores can reach the central nervous system and cause muscle spasms, extreme stiffness, elevated tail, and retracted lips. Ultimately treatment consists of using muscle relaxants, antibiotics, and adequate nutrition but even with those measures 75% of horses do not survive. Foals require a 3-dose series. Broodmare and adult horses usually require an initial 2-dose series. In Broodmare horses, they will require an additional booster dose 4–6 weeks pre-partum then annually thereafter. In adult horses, they will require a booster dose annually thereafter and following injury.
Western Equine Encephalomyelitis (WEE) and Eastern Equine Encephalomyelitis (EEE)
These two illnesses I will combine because their key difference is only in the geographical location. WEE and EEE are viral diseases often transmitted from mosquito bites contracted from wild birds and rodents. The two conditions together are also more commonly known as “sleeping sickness” for horses. EEE is notoriously more deadly than WEE, usually with only 15% of horses affected surviving. 50% of horses affected with WEE can usually survive which is better. Both conditions present similarly. Clonic and anorexia are usually initial symptoms followed by neurological issues such as seizures, blindness, ataxia. Foals typically will require a 3 or 4-dose series. Broodmare horses and adults require a 2-dose series. Boosters in Broodmare horses can be given 4–6 weeks pre-partum and annually in adults.
West Nile Virus (WNV)
West Nile Virus is another mosquito transmitted disease that acts very similarly to WEE and EEE. The virus enters and affects the central nervous system and causes brain and spinal cord inflammation. Key symptoms include ataxia, lethargy, weakness, muscle trembling, and depression. One third of cases die and among survivors, 40% experience lasting neurological deficits such as prolonged ataxia. Foals typically receive a 2 or 3-dose series. Broodmares should not receive this vaccination unless at a high risk for the disease. Adult horses will receive either a single or 2-dose series. Boosters can be administered annually in both adults and broodmares and 4–6 weeks pre-partum in broodmares.
Rabies
Rabies virus is typically transmitted via bite from rabid animals such as raccoons, bats, skunks, or foxes. The virus spreads rapidly from the site of infection and its effects concentrate in the brain and salivary glands. Clinical signs are usually unpredictable. Horses can be very lethargic and have poor athletic performance to being very aggressive and convulsive. The effects are irreversible and there is no treatment. It is usually recommended to euthanize horses that contract rabies and for caregivers who handle the horse, on top of horses being vaccinated, the owners and veterinarians should also be vaccinated against it as well to protect themselves. Foals usually receive a single or 2-dose series. Broodmare and adult horses usually receive a single dose. Booster series are usually given to broodmare and adult horses annually. Additionally in broodmare horses, administering a booster pre-partum or or pre-breeding is recommended.
Conclusion
Horses are just as susceptible if more so to contract certain diseases if not vaccinated properly. Make sure to start early on when they are foals to avoid any issues down the line for the health of the horse. I have compiled a small chart below of just the key differences. Thank you for reading.
Best,
Walker C. Brown
