Clinical aspects of immunosuppression in poultry

Immunity is ability to stop an infection. Immunosupression is a status where the immunity is reduced. Humoral (antibodies) and/or cell immunity may be depressed. Immunosupression can be caused by infectious agents, improper feeding balance (deficiencies), lack of biosecurity, management failures, stress or by a combination of these factors. Each of these possible causes must be seriously worked out to prevent the consequences of immunosupression on profitability. Environmental factors and numerous infectious pathogens have been identified as a multi-factorial cause of various degrees of immunosupression. Mainly subclinical character and coinfections make the diagnosis of the primary immunosuppressive agents difficult. On the other hand, early diagnosis and identification of contributing factors are important to develop strategies to fight immunosupression in birds successfully. A combination of biosecurity measures, optimized housing condition and stress reduction together with appropriate vaccination strategies is necessary for the successful control of immunosupression in commercial poultry