Diagnosis, Treatment, and Prevention of Lyme Disease In Horses

Lyme disease is often confounding because the symptoms can mimic so many other ailments. If Lyme disease in humans is difficult to diagnose, imagine how aggravating it can be to determine Lyme disease in horses. But through detective work and due diligence, you can make sure your horse gets the treatment it needs if it contracts Lyme disease.

What Is Lyme Disease?

Lyme Disease is an infection caused by the Borrelia burgdorferi (Bb) bacterium carried by black-legged ticks, most commonly the deer tick and Western black-legged ticks. The name comes from the region of origination, the Lyme, Connecticut area. In 1975, 51 residents were diagnosed with an unusual form of arthritis.


Researchers isolated a spirochete in the Lyme disease patients that had been discovered in black-legged ticks. These ticks are carried primarily by deer and rodents in the northern US, and by lizards in the isolated southern states.


Interestingly, Lyme disease in horses does not vary that much from Lyme disease in humans.

Signs of Lyme Disease in Horses

If you live in a rural area, particularly in an area of concentrated tick population like the Northeast or the Midwest United States, your horse is going to get ticks. Contact with ticks does not mean Lyme disease or even infection.


Lyme disease-carrying ticks are increasing their range, so it is important to watch for signs such as:

  • Joint inflammation, stiffness, and lameness that tends to shift from limb to limb
  • General lethargy
  • Irritability
  • Jumpiness
  • Sensitivity to grooming
  • Headshaking

If left untreated, chronic Lyme disease can result in neurological problems, like general disorientation, as well as affecting the eyes with inflammation or even moon blindness.

The Difficulty of Diagnosis

One of the biggest problems with the diagnosis of Lyme disease is that there are no absolutes. The “bullseye” rash around a tick bite that can appear in humans cannot be seen on horses, and even on humans it is not confirmation that the person has contracted Lyme disease or even been infected with Bb.


Like humans, not all horses show signs and not all signs mean disease. The mimicry of Lyme disease to other conditions like general arthritis also makes the diagnosis tricky. A big animal doctor will often have to diagnose and treat through a process of elimination.

The Treatment of Lyme Disease In Horses

While the treatment of Lyme disease in horses is as simple as prescribing antibiotics, it is not a decision made immediately without further detective work. Veterinarians are just as hesitant to quickly prescribe antibiotics for horses as most doctors are for human patients.


When other ailments have been eliminated as causes, a veterinarian will prescribe oral doxycycline or tetracycline. IV antibiotics are more effective, but much more expensive as they likely require a stay at the clinic. The duration of oral antibiotics is usually about 30 days. If your horse does not respond to this treatment, or has a relapse, IV administration may be necessary.

The Prevention of Lyme Disease In Horses

You know the drill—“An ounce of prevention is worth a pound of cure.” There are some simple ways to try to keep ticks off your four-legged friend, as well as some that are a little more strenuous and back-breaking, but worth the result.


There is no vaccine against Lyme disease. The best way to prevent tick bites and Lyme disease in horses is to limit exposure. Do the following:

  • Groom your pasture and turnaround areas.
  • Keep grass at 5” height or less.
  • Eliminate shrubs and bushes.
  • Trim overhanging limbs.
  • Manage carrier population (rodents/deer/lizards).
  • Use spray repellant like Equiderma Neem & Aloe Spray.
  • Check your horse every day for ticks and remove them carefully. Key areas are:
    • Legs
    • Head
    • Neck (base of mane)
    • Belly
    • Tail

Prevent with Proper Grooming

Your daily grooming session is the perfect time to check for ticks, along with other skin and health issues. To enhance your horse’s skin care regimen, try Equiderma skin care products for horses.

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