In our last newsletter, we discussed some of the symptoms of Lyme disease. (Available here) As we discussed, the disease can look like anything.
Where can Lyme disease be found?
We don’t have accurate information on Lyme disease prevalence in horses, but we have a map of Lyme disease prevalence in dogs.
Diagnosing Lyme disease in horses:
Cornell University has a test for Lyme disease, the Equine Lyme Multiplex Assay. It tests different types of surface proteins to determine exposure to the disease.
➡ OspC -> infection within the last two to five months
➡ OspF -> indicates chronic infection
➡ OspA -> May be from vaccination, or may be a naturally infected horse
However, some horses with Lyme disease have antibody numbers that are too low to be considered infection (negative for Lyme disease). Rutgers University has developed a DNA test for equine Lyme disease. However, that is not yet available for the public.
Other tickborne diseases:
Some horses have symptoms that are suggestive of Lyme disease, but test negative. They may have an infection with a different tickborne disease. Common tickborne diseases (besides Lyme disease) include:
» Rocky Mountain spotted fever
» Piroplasmosis (Babesiosis)
» Anaplasmosis
» Ehrlichiosis
» Tularemia
» Powassan Virus disease
» Heartland virus
» Bartonellosis
Horses with other tickborne diseases usually test negative for Lyme disease.
Recurrence:
After successful treatment for Lyme disease, it is not unusual for horses to become reinfected. This can happen because:
☛ The spirochetes play hide and seek. Spirochetes can go into hiding during treatment, but come out of hiding to cause disease at a later date.
☛ The horse may be subject to ticks that carry the Lyme spirochete and become infected with a “new” infection.
☛ The horse may have been infected at some point in the past, mounted an antibody response with few or no symptoms. At a later date, when stressed, the existing spirochetes may cause disease. Some veterinarians have the opinion that if your horse has been exposed but has subtle issues, that your horse does not need treatment.
When there is a flair up, veterinary treatment is appropriate.
Treatment:
Veterinary care:
Your veterinarian can best advise you on appropriate antibiotic treatment. Common treatments include doxycycline, oxytetracycline, or minocycline. Other treatments can include penicillin or cephalosporins.
Supplement use:
Some supplements may be helpful to increase the “brightness” of horses that have been treated for Lyme disease. These supplements may be helpful:
Equine Lyme Support: A blend of baicalin from scutellaria baicalensis (Chinese Skullcap), luteolin from origanum vulagare (Oregano), and resveratrol from polygonum cuspidatum (Japanese knotweed) designed to support a horse with
Lyme disease.
Luteolin: In human studies, this is one of the phenolic compounds that have been linked to patients having more energy and a greater sense of well-being after taking it for 6 months. It is one of the ingredients in Equine Lyme Support.
Hyaluronic Acid: Studies have shown that the Lyme spirochetes decrease hyaluronic acid synthesis in fibroblasts. Additional hyaluronic acid for support may be helpful.
Mov-Ease: Mov-Ease may help a horse with Lyme disease because it may help reduce inflammation and oxidative stress.
CoQ10: CoQ10 also is anti-inflammatory and anti-oxidant. Like Mov-Ease, it may be helpful for you horse.
We do the best we can for our horses. Lyme disease is frequently difficult to manage. Knowing about the disease is helpful, especially since the disease can look like anything.
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Disclaimer: Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease or health condition.
©Joan Kulifay 2025