Infectious Synovitis (Mycoplasma synoviae / MS) in Poultry
Guide covering Mycoplasma synoviae etiology, joint exudate, breast blisters, lameness, MS-H vaccine, and Tylosin therapy.
Scientific Overview
Infectious Synovitis is an acute-to-chronic infectious disease of chickens and turkeys caused by Mycoplasma synoviae (MS). It primarily targets synovial membranes of joint capsules, tendon sheaths, and bursa, leading to swollen hock joints, breast blisters, severe lameness, and growth retardation.
Etiology & Transmission of Mycoplasma synoviae
Mycoplasma synoviae (MS) is defined as a cell-wall-less bacterium causing synovitis and subclinical upper respiratory tract infection.
Transmission occurs vertically through breeder eggs and horizontally via respiratory droplets. MS can remain persistent in flocks for the duration of their life cycle.
Pathology: Swollen Hock Joints & Tendon Exudate
Clinical signs and lesions include:
- Lameness & Hock Swelling: Birds wobble on legs with hot, swollen hock joints and footpads.
- Viscid Synovial Exudate: Joint cavities contain cream-colored to honey-like viscous fluid that hardens into caseous pus in chronic stages.
- Sternal Bursitis (Breast Blisters): Prominent fluid-filled blisters over the keel bone due to birds resting on litter.
Control: MS-H Live Eye-Drop Vaccine & Antibiotics
Prevent MS by acquiring MS-free breeder stock and administering live MS-H vaccine via eye drop at 5–6 weeks of age. In active outbreaks, administer water medication with Tylosin, Tiamulin, or Chlortetracycline.