There are several disease carried by ticks that can be transmitted to your horses. Examples include Lyme Disease and Anaplasma phagocytophilia (formerly called Ehrlichia equi) .
Prevention is the key. Keep those ticks off you and your horse as you ride this fall.
In past years we've seen numerous cases arise one to two weeks after a trail ride. The Dodgeville and western Wisconsin region/state parks have often been the area in question. However, any ride in tall grass or woods could result in ticks attaching.
Stay on the trails. Don't ride in tall grass.
Spray your horse's legs, bottom of body, mane and tail with a tick spray. The spray with an active ingredient of permethrin will work the longest. Respray if you ride for several hours or your horse's legs get wet.
Thoroughly look over and feel your horse's skin, checking for ticks as soon as you get home. Check again over the next two or three days. Sometimes they show up later.
If you find ticks on your horse, watch it closely for signs like lethargy, off feed, dullness, stiffness or lameness.