During recent years the pig industry has showed a radical change in disease patterns. In the last decade the emergence of immunosuppressive viruses (ISVs) has meant a significant change in the pattern of the diseases seen in pigs. The most common diseases related to this are PRRS, Swine Influenza Virus, Pseudorabies, and Swine Fever. Other diseases include Porcine Circovirus 2 and Post Weaning Multi-systemic Wasting Syndrome. The goal of veterinarians is to optimize the benefits of using antibiotics, appropriate preventative measures, and management to deal with these infections in immunosuppressive diseases. Some antibiotics can weaken the immune system (Tetracycline causes depletion of the immune system) and others work to strengthen the response of the animal. Effective control of ISVs may require fundamental changes in management, which could include major system changes. The prudent use of antibiotics to control the secondary infections is part of the control program. Aspects related to the impact of these products in immune system and the adverse effects in other organs, as kidneys, for instance, are relevant to choose the ideal drug. In addition biosecurity and effective disinfection programs can play a significant role in minimizing the problem.