In pigeon Newcastle disease is caused by pigeon paramyxovirus type-1 (PPMV-1) which is a variant of avian paramyxovirus-1 (APMV-1) and characterized on the basis of monoclonal antibody-binding profiles. PPMV-1 in pigeons produces digestive and nervous disturbance and mortality and morbidity reaches up to 40 and 70 %, respectively. Submucosal to echymotic haemorrhages in proventriculus and intestine, tracheaitis, nephritis and encephalitis were observed in pigeons died PPMV-1 infection. The second most important disease found in pigeons, is coccidiosis which is well known among pigeon farmers with the common name of "KHUNI PACHISH". Coccidiosis causes severe blood mixed diarrhea and enteritis . In coccidial infection, the immune system of bird becomes depressed and are more susceptible to bacterial and viral infections.