05/04/2026
Core Vaccines vs. Risk-Based Vaccines: What Midwest Horse Owners Should Know
Core vaccines are recommended for every horse because they protect against diseases that are severe, widely distributed, or a public health concern. In horses, those include tetanus, rabies,
West Nile virus, and Eastern and Western equine encephalomyelitis. Risk-based vaccines are selected differently. They are used according to a horse’s age, travel, housing, breeding status, exposure to outside horses, and regional disease pressure.
In the Midwest, the risk-based vaccines that most often deserve discussion are influenza, EHV-1/4, strangles, Potomac Horse Fever, and, in some cases, leptospirosis. A closed-herd pasture horse does not carry the same exposure risk as a show horse, lesson horse, broodmare, or horse living on wet ground with heavy insect and wildlife activity. That is where risk-based planning becomes more specific.
Here is the quick breakdown:
Influenza: important for horses that travel, show, board, train, or mix with new horses.
EHV-1/4: important for young horses, show horses, breeding farms, and horses in busy barns. Pregnant mares often need a separate EHV schedule.
Strangles: worth discussing for farms with a history of it, young horses, or horses with frequent outside exposure.
Potomac Horse Fever: a bigger concern on farms near streams, rivers, ponds, wet pastures, or irrigated ground, especially as we head into summer and fall.
Leptospirosis: worth a conversation on farms with standing water, flooding, heavy wildlife pressure, or broodmares, because it has been associated with abortion, eye disease, and kidney problems.
Bottom line: Core vaccines are for every horse. Risk-based vaccines are for the horses whose lifestyle, environment, or region puts them in the line of fire. That is why there is no true one-size-fits-all vaccine program.
Talk with your veterinarian before spring and summer exposure ramps up. The best vaccine plan is the one built for your horse, your farm, and your risk.
