Biology, pathogenesis and control of syngamus trachea infection in chicken

Abstract

In a study conducted for a period of one year on the biology, pathogenesis and control of Syngamus trachea infection in chicken, it has been found that the infection was more in very young birds below 1 to 2 months of age, reared under the free range system and during the monsoons. The egg cultures became infective on the seventh day of culturing. A dose of 3,000 infective eggs or larvae was found to be suitable for a successful establishment of infection in chicks. Experimental infection could be set up by the direct feeding of the infective eggs or larvae without the necessity of the intervention of any transport hosts like earthworms. A detailed study on the stage to stage development of the parasite was carried out. They established in the trachea by the eighth day and attained patency 18 to 22 days following infection. Gaping movements, nodular growths on the tracheal mucous membrane, haemorrhage and production of mucus in the trachea, consolidation and ecchymosis of the lungs were the chief clinicopathological symptoms observed. Anthelmintic efficacy of mebendazole, thiabendazole, albendazole and ivermectin was assessed on the basis of the reduction of ova in the droppings, disappearance of worms from the trachea and gain in body weight of the treated birds. Mebendazole administered at 40 mg per kg body weight was found to be the most effective among the drugs tried closely followed by albendazole given at 15 mg per kg body weight and then thiabendazole at 500 mg per kg body weight. Ivermectin dosed at 200 micrograms per kg body weight subcutaneously was found to be the least effective. Assessment of the effect of irradiation at 5 KR on the development of S. trachea in chicken was attempted twice with no conclusive results.