Lyme disease is caused by the tick-borne bacteria *Borrelia burgdorferi*. Horses become infected with the bacteria when an infected tick feeds on them.
Laminitis refers to inflammation of the lamellae, the support structure that holds the coffin bone in place within the hoof capsule. The lamellae are extremely sensitive, making laminitis a very painful condition.
Lantana poisoning is a condition that occurs when horses ingest large amounts of the lantana plant, also known as yellow or red sage.
Lymphoma is a cancer of the lymphatic system, which is involved in moving byproducts of the immune system throughout the entire body. Lymphoma can be present anywhere in the body and is categorized into four subtypes; multicentric, intestinal, mediastinal, and cutaneous.