Outbreak of leucocytozoonosis in commercial white leghorn layer chickens Thilagavathi K.1,*, Selvaraj J.1, Velusamy R.2, Prasath N. Babu1, Prabu P.C.1, Hariharan J.1 1Department of Veterinary Pathology, Veterinary College and Research Institute, TANUVAS, Orathanadu, Thanjavur District, Tamil Nadu - 614 625 2Department of Veterinary Parasitology, Veterinary College and Research Institute, TANUVAS, Orathanadu, Thanjavur District, Tamil Nadu - 614 625 *Address for Correspondence: Dr K. Thilagavathi, Department of Veterinary Pathology, TANUVAS, Orathanadu, Thanjavur District, Tamil Nadu - 614 625, E-mail: thilagapatho@gmail.com
Online Published on 03 February, 2023. Abstract Seven white Leghorn layer chickens from a layer flock containing 1300 birds were received for necropsy. Externally the birds showed pale comb, wattle, skin, beak and conjunctival mucous membrane. The comb also showed multifocal reddish cysts of 0.5 to 1 mm diameter. On internal examination, tracheal lumen and peritoneal cavity contained blood mixed fluid. Subcutaneous tissues of neck, pectoral muscle, proventricular mucosa, gizzard, intestine mucosa, liver, pancreas, thymus and bursa of Fabricious showed multiple reddish cysts of 0.5 to 1 mm diameter. In addition, epicardium of heart, crop mucosa, proventriculus, gizzard, intestinal serosa as well as mucosa, liver, pancreas, oviduct serosa and broad ligament, spleen, skull and brain meninges revealed multiple raised white thin cysts of 1 to 2 mm diameter. Both kidneys were enlarged, haemorrhagic with blood clot adhered. Ovarian follicles were mishappened, shrunken or haemorrhagic with raised red or white thin cysts of 1 to 2 mm diameter. Heart, intestine and liver cyst content revealed various sizes of round schizonts of Leucocytozoon. Histopathologically, comb and pectoral muscle revealed ruptured megaloschizont of Leucocytozoon with haemorrhage. Heart, lung, proventriculus, gizzard, intestine, liver, pancreas kidney, ovary, oviduct, thymus, spleen and bursa of Fabricious were revealed the megaloschizonts. The megalo-schizonts appeared either as singular or aggregates and contained numerous basophilic merozoites. Each of the megaloschizont was round unilocular structure with intact or irregular capsular wall without inflammatory reaction and a few showed ruptured wall with haemorrhage and inflammatory reaction around it. Based on the gross and histopathological lesions, the present case was confirmed as leucocytozoonosis in chicken. Top Keywords Layer chicken, Leucocytozoonosis, Pathology, White Leghorn. Top |