Ganesh K Sawale¹*, M Lakshman¹, NR Bulbule², MM Chawak², Y Ravikumr³ and D Madhuri¹²

¹Department of Veterinary Pathology, College of Veterinary Science, P.V. Narsimha Rao Telangana Veterinary University, Rajendranagar, Hyderabad, India
²Poultry Diagnostic and Research Centre, Loni Kalbhor, Pune, Maharashtra, India
³Department of Veterinary Pathology, College of Veterinary Science, Korutla, (PVNRTVU) Telangana, India

*Corresponding Author: Ganesh K Sawale, Department of Veterinary Pathology, Mumbai Veterinary College, Mumbai (Maharashtra Animal and Fishery Sciences University, Nagpur), India.

Received: March 02, 2026; Published: April 07, 2026

Abstract

In this study the investigation on cause of lameness due to Mycoplasma synoviae (MS) infection in poultry farms in Telangana and Maharashtra states were carried out. Detailed flock history of each affected flock was collected, and necropsies of two to three ailing sacrificed birds and dead birds were conducted. Diagnosis of MS was done by serology, PCR, electron microscopy and histopathology. In this study, nineteen parent flocks, two commercial layer (CL) flocks showing signs of lameness were considered. Lameness due to hock joint and foot pad swelling was a characteristic clinical sign particularly observed in BP (broiler parent) male birds. Female birds, although serologically positive for MS, did not show signs of lameness. The morbidity from 0.3 to 100 percent in male BP flocks and mortality up to 10 percent was reported. In MS-affected female CL birds, lameness along with hock joint swelling as well as paleness of the comb and breast blister was a consistently feature. Grossly, severe unilateral or bilateral swelling of hock joint/ footpad joint with turbid to caseous exudate in most birds and blood-tinged fluid in a few birds and breast blister in male BP birds with less severe lesions in female BP birds. In CL birds, the gross lesions were similar to BP birds but showed less severity, and anaemia was constantly observed. Histopathologically, in addition to MS-specific lesions, perivascular lymphoid infiltration around blood vessels in the tendon sheath, liver, and brain as well as multinucleated giant cells in the tendon was observed. Mild tracheitis and interstitial and alveolar pneumonia along with heterophilic and lymphocytic infiltration in the heart was observed. In the ultra- structural study, six out of seven tendon specimens showed mycoplasma-like organisms (MLO) in the tendons and joint fluid. Among twenty one flocks affected with tenosynovitis, samples from three flocks (one CL and two BP) were detected by conventional PCR.

Keywords: Broiler Parent; Diagnosis; Electron microscopy; Gross Pathology; Histopathology; Mycoplasma synoviae; PCR

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Citation

Citation: Ganesh K Sawale., et al. “Pathology and Electron Microscopy of Mycoplasma synoviae Infection". Acta Scientific Veterinary Sciences 7.12 (2025): 41-52.

Copyright

Copyright: © 2026 Ganesh K Sawale., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.