Lyme Vaccination for Horses

Lyme disease is becoming more and more common in humans, dogs, and horses in our region.  It is spread by ticks and there are two primary ways to counter infection: 

1) Avoid tick bites (use tick repellents) and remove ticks within 12 hours of attachment,
2) Vaccinate against Lyme disease, when possible.
There are several Lyme vaccines labeled for dogs, one of these vaccines has been used fairly extensively in horses and does not interfere with laboratory test results.  As a veterinarian, I am allowed to use vaccines in an extra-label fashion, meaning that I may use a dog vaccine in a horse if deemed that the benefit of vaccination outweighs risk. Current research suggests that horses differ from dogs in their response to Lyme disease, as most will not become ill. But for the horses that do become ill with Lyme disease, treatment is expensive (upwards of $400), and can result in loss of performance during a show season.
Due to rising concern about the disease in horses I have decided to offer vaccination for previously unvaccinated horses following these guidelines this year:

  • First, do a blood test (4Dx) to determine if the horse has already been exposed. This test can be run on the farm and takes about 10 minutes to have results. (Cost $30)
  • If the horse is negative for exposure, I can utilize a canine vaccine that has been shown somewhat protective in horses. (In both dogs and horses, animals are not necessarily immune to the disease altogether, but the animals that have been vaccinated tend to have less severe illness.)  The vaccine is administered, then boostered at 3 weeks, and again at 3 months. Based on current research, the protective effects of the vaccination are short lived, requiring frequent (every 6 month) vaccination after the initial series of 3 vaccines are given. (A scientific overview of Cornell University’s pony studies on Lyme treatment and vaccination:http://www.ivis.org/proceedings/aaep/2003/divers2/ivis.pdf). The cost per vaccine dose is $36, if scheduled prior to Feb. 28, 2014.  On March 1 there will be a price increase that depends on the manufacturers upcoming price increase.
  • Because the vaccination initially requires a series of three visits and a blood test, it can be costly. To help reduce expenses, Lyme vaccinations scheduled for Saturday, March 8, March 29, and May 31 and June 2, will be offered a 50% discount on the normal call charge for your area.  This call charge may be further split between multiple owners at one site.
  • Due to concerns about reactions, I will NOT administer the Lyme vaccine at the same time as other vaccinations. There is currently no equine vaccination for Lyme disease and I am utilizing a canine vaccination off label; owners will be asked to sign a waiver to this effect.

If a horse turns up positive on the stall side test (4Dx), I would not recommend vaccination at this time. If you are interested we can utilize further blood testing (Multiplex) to see whether the exposure is of great enough concern to consider treatment.  We are NOT recommending treatment for horses who are not showing clinical signs.

Horses that were already vaccinated for Lyme disease last year need to be boostered this year, preferably a minimum of 2 weeks before ticks become active, which was in mid-March last year.  From here forward, horses that were vaccinated for Lyme previously are recommended to have a booster every 6 months to maintain protective immunity throughout tick season.

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