Fig. 1

Pathological studies of infected chickens and inoculated chickens.The infected chickens, which showed clinical symptoms including movement disorders, erect feathers and stunted growth (a1), were killed, and anatomical investigations revealed the presence of thick, clear to milky exudate in enlarged joints (a2, a4) and foot pads (a3). Similar to the clinically infected chickens, the inoculated chickens exhibited symptoms such as movement disorders, erect feathers and stunted growth (b4). The anatomical investigations showed that thick, clear to milky exudate was present in enlarged foot pads (b2, b3), joints (b6, b7), keels (b8) and wings (b11). In addition, air sacculitis (b10) was observed in infected chickens too. Mock-injected chickens’ foot pads (b1), joints (b5) and air sacs (b9) were compared with those of the infection chickens. Colonies of M. synoviae were grown in solid medium (b12)