What is Lyme?
Lyme disease is a tick-borne disease that is carried only by deer ticks. Deer ticks are found in every state but Hawaii, but they are most prevalent in the eastern half of the United States. They are typically found in tall grasses, where they hang on the tip of the grass with their legs outstretched, waiting to latch on to a passing animal.
Once the tick attaches to its host, it takes about 36-48 hours for the Lyme bacteria to be transmitted. While there is an equal distribution of Lyme-carrying ticks between the nymph and adult stages, Lyme is transmitted most frequently by ticks in the nymph stage. This is because they’re far smaller than adults, and are thus less likely to be discovered and removed before transmission. Adults are approximately the size of a sesame seed, while nymphs are about the size of a poppy seed.
Lyme disease can affect a wide range of species, including horses and humans.
A few documented clinical signs of Lyme disease in horses include a lump where the tick was, swollen joints, and eye inflammation.
While we do occasionally observe these signs in the horses that we test for Lyme, there are others that we see in almost every horse that we test. Lethargy and general stiffness are often present, but the most consistent and tell-tale symptom we have seen is increased sensitivity of the skin. This can present as grouchiness or restlessness during grooming, or excessive twitching of the skin when touched with a hand or brush.
Loss or lack of muscle tone and general changes in behavior can also be an indication that you may want to test for Lyme. We don’t usually observe these symptoms in our rescues because we don’t know them well enough yet, but you probably know your horse well enough to notice these changes.
A blood test by a veterinarian is required to diagnose Lyme disease. The cost of the test varies between veterinarians, but is very reasonably priced. There can be false positives, or your horse can be asymptomatic, but if you got the test because you’re observing the symptoms described above, it might be worth it to consider treatment.
Usually, the treatment for Lyme disease in horses is a round of antibiotics. The dosage will depend on your horse’s weight. It’s important to do the full treatment recommended by your veterinarian in order to make sure the Lyme bacteria is sufficiently decreased to mitigate symptoms (unfortunately, it’s not possible to completely get rid of it). If it’s not adequately decreased, the infection could come back with a resistance to those antibiotics, making it harder to treat.
The antibiotics will depopulate the Lyme bacteria, but they will also affect your horse’s gut bacteria. A round of probiotics after the Lyme treatment could help your horse feel its best.
While treating Lyme disease is not a cure-all for physical and behavioral issues, we have found it to be very beneficial to our horses. They appear to feel better physically and emotionally towards the end of the treatment.
As with most things, an ounce of prevention goes a long way. Stay tuned for our next blog, where we will share with you some of our favorite tips and tricks to prevent tick bites!