We recently had a horse come into our rescue with hundreds of ticks. This prompted us to do some research about the best approach to eliminate them. There are many recommendations and we do not discredit any of them. This is just what we did and what worked for this specific horse.
If the ticks are a few, they can be removed by hand. It is recommended not to twist them, but rather to use firm, straight backward pressure. Twisting can result in the head remaining in the horse, causing infection and disease. A tick comb may be quite useful.
In the case of many ticks, there is a 3 prong approach - this is what we did.
1. Ivermectin kills ticks. We administered a regular dose as if we were de-worming the horse. It is recommended to repeat this after 2 weeks if ticks are still present.
2. Permectin - this is a topical tick killer similar in application to "Frontline" products used on dogs. It is available through your local veterinarian. The bottle contains an applicator with a metered dose. It should be applied using gloves to avoid contact with your skin. READ MANUFACTURER'S WARNINGS!!! The "dose" is applied as a stripe from the forelock to the tail base. Then using a small cloth, absorb some of the product to wipe on the forehead. You may want to apply some on the chest too via cloth if that area is infected. The manufacturer instructs to use again in 2 weeks if ticks are still present. BUT - what we learned was to place the "stripe" of medication in a different area. Don't follow the same path. It will irritate the horses skin!
3. Manual Removal - For this we recommend a fine toothed flea and tick comb available at any pet supply store. They are about $6.00. You will need to prepare a vehicle to store and kill the ticks you collect. Make a TICK JAR. Use a glass jar with a secure lid. Place about a half inch of isopropyl alcohol in the jar. As you "comb" the animal, place any captured ticks into this jar. Swirl to coat and kill. Do not let them loose on the ground. They will simply search out a new host!!!
So in the case of hundreds, we had to use 2 rounds of both Ivermectin and Permectin, and we combed for ticks daily placing them into the Tick Jar. The majority of the ticks were gone in the first few days, but they continued to appear for about 4 weeks. Where they were hiding, we do not know. Yes, you may have nightmares, but your horse will be so grateful!