Lyme Disease in Equines

Lyme Disease in Equines

We live in an area rich with Ixodes ticks that carry the bacteria Borrelia burgdorferi, which is associated with Lyme disease in people, dogs, and horses. The risk of Lyme disease in your horse (while lower than you or your dog) is increasing at a steady pace as a higher proportion of infected ticks are found in this area every year, so it`s critical for us to understand how to best prevent and deal with Lyme disease in our horses.

You are most likely to find ticks hanging on to your animals (or yourself) in spring or fall. This is when the large adult females will feed, so the common misconception is that these are the only times of year when ticks are around. The younger nymphs feed preferentially during the summer and do not engorge like the adults (and consequentially are much tougher for you to find and remove) but can certainly still transmit Borrelia. It takes these ticks 1-2 days to transmit the bacteria, but applying caustic substances or burning the ticks may accelerate this infection process. This is why we recommend firmly grabbing the tick and using a slow consistent pulling or twisting motion to cause the tick to release its grip.

Not every horse infected with Borrelia will contract Lyme disease, but some symptoms to watch for are:

 Sudden hypersensitivity to touch i.e. Sudden dislike for being saddled or brushed

 Weight loss

 Lameness or swollen joints (may come and go or switch joints)

 Local swelling / muscle tenderness

 Low Grade Fever

Most typically a horse suffering with Lyme disease will show us only some of these pretty non-specific symptoms, so how do we know we may be dealing with a Lyme infection? We may recommend blood testing to confirm Lyme disease if we have ruled out other causes of the aforementioned symptoms. Depending on results, treatment of your horse with antibiotics may be indicated.

Preventing ticks is definitely the best way to prevent Borrelia infection. K9 Advantix is an off-label but safe way to aid in protecting your horse from tick bites. It is safe to use as often as every 2 weeks to help protect your horse, but continue to check your horse’s legs and belly as the spot-on products don’t always get completely even coverage across the body. If we check for ticks daily in our pastured horses, we will hopefully remove them prior to infection. Continue to try and keep mice out of the barn and feed bins, as the ticks use them as a crucial part of their life cycle.

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