A method to reduce the likelihood of conjunctivitis in farm animals, especially cattle, includes the step of injecting an implant containing an antibiotic effective against the microbes associated with conjunctivitis subcutaneously into the animal in close proximity to the eye. Preferably the implant includes a matrix to allow time release of the antibiotic and the implant is placed in the animal near the first part of July. Also preferably the antibiotic is tetracycline.