This is not your average discussion about what to vaccinate your horses with. That would be a discussion to have with your veterinarian who knows you and what diseases are in your area. However, to prepare you for that discussion, I will attempt to give you  a bit about immunology, a bit about vaccination and disease history and a bit about false advertising by vaccine companies. You should NOT be anti-vaccines but you should be aware of how they are just one tool in your tool kit protecting your horses from disease. In a nutshell: vaccinate for diseases that can kill your horses but for those that will only make a healthy horse mildly sick, use all the tools in your kit in addition to vaccines. TheHorsesAdvocate.com - Helping Horses Thrive In A Human World