Pathomorphology of Concurrent Peste des Petits Ruminants (PPR) and Contagious Caprine Pleuropneumonia (CCPP) in a Cross Breed Goat Flock

Abstract

Background: Respiratory diseases are very common in goats and cause severe economic loss to the rural poor farmers. Proper identification of the actual pathogen(s) responsible for the respiratory infections is critical for timely and proper management of those diseases. The present communication describes the spontaneous occurrence of concurrent Peste des petits ruminants (PPR) and contagious caprine pleuro-pneumonia (CCPP) in a goat flock.Methods: An outbreak of respiratory disease in a goat flock consisting of 45 Tellicherry cross bred animals in varying age groups was investigated during the month of February 2019 in Namakkal district of Tamil Nadu. Information of disease outbreak and flock details were collected. Samples from live (nasal, ocular and rectal swabs) and dead (lung, spleen and mesenteric lymph nodes) were collected for detection of Peste des petits ruminants virus (PPRV) and Mycoplasma capricolum subsp.capripneumoniae (MCCP) antigen by polymerase chain reaction. Tissues from heart, lung, liver, kidney, intestine, spleen and lymph node were collected in 10% neutral buffered formalin for histopathological examination.Result: Out of 45 goats at risk, 23 showed clinical signs and 17 died of disease conditions with morbidity, mortality and case fatality rate of 51.11%, 37.77% and 73.91% respectively. PPR was confirmed by RT-PCR with M gene specific primers (191bp) and CCPP was confirmed by PCR with 16S rRNA gene fragment (316 bp). Affected animals showed clinical signs of pyrexia, anorexia, marked depression, mild erosions in the oral mucosa, nasal and ocular discharge, coughing and diarrhoea. Necropsy examination revealed congested oral mucosa, extensive pleuritis with large fibrin clots on lung surface and greyish pink consolidation of cranial lobes and anterior parts of diaphragmatic lobes. On section, consolidated areas were granular in appearance. Histopathology of lung revealed thickening of pleura, interlobular septa and alveolar wall by fibrin deposition and infiltration of inflammatory cells. Pulmonary congestion, infiltration of neutrophils and mononuclear cells, syncytial cell formation with eosinophilic intracytoplasmic and intranuclear inclusions were also noticed. Visceral organs showed degenerative and necrotic changes.