It's important to remember that:
* Atypical lymphocytes are not a diagnosis in themselves. They can be a sign of many different conditions, both serious and benign.
* Only a veterinarian can properly diagnose and treat medical conditions in horses. They will take into account the horse's complete medical history, conduct a physical exam, and likely run additional tests to determine the underlying cause of the atypical lymphocytes.
If you are concerned about your horse's health, please contact a veterinarian immediately. They are the only ones qualified to provide accurate information and treatment for your horse.