Here are three parasites horses commonly have:
1. Strongyles: Roundworms in the digestive tract. Can cause anemia, colic, and death.
2. Ascarids: Large roundworms in the small intestine. Can cause weight loss, coughing, and diarrhea.
3. Bots: Fly larvae attached to the stomach lining. Can cause ulcers, weight loss, and colic.
These are just a few examples. Talk to your veterinarian about parasite risks in your area and how to protect your horse.