How can poultry farmers effectively control Mycoplasma synoviae infections?

Mycoplasma synoviae poses a significant threat; how can poultry farmers effectively control and prevent it?

Swollen joints and lameness in chickens? How to diagnose and treat mycoplasma synoviae infection?

Let's approach today's article with some questions in mind.

Mycoplasma Synoviae Infection

（I）Clinical Symptoms

    In the early stages of the disease, chickens are in good spirits and eat normally, though some are underweight and feel bony when touched. In the middle and late stages, chickens become listless, have a decreased appetite, pale combs, limp, swollen joints, swollen foot pads, and swollen breasts. Some chickens sneeze and cough, and laying hens experience delayed start of production, no peak egg production, decreased egg production, and reduced hatchability.

（II）Pathological Changes

    The primary lesion is synovitis of the joints and keels. Joints swell and the synovium thickens. Initially, the joint fluid increases in volume, becomes translucent, and viscous. In the middle stages, it becomes a pale yellow, gelatinous exudate. Later, it becomes pus or a yellowish-white, cheesy exudate. Exudate is often present in the tendon sheath and synovial bursa (similar to avian viral arthritis).

    Some cases may have cysts and hemorrhages in the chest keel, jelly-like effusions, and respiratory tract cases may have inflammatory lesions. Sometimes there may be hepatosplenomegaly, kidney enlargement, pale color, and atrophy of the thymus and Fasciola.

Case Diagram of Mycoplasma Synoviae Infection

How to Quickly Determine Whether the Disease is Mycoplasma Synoviae Infection？

Joint Swelling:It often occurs in the hocks, foot pads, or wing joints and may be accompanied by lameness or difficulty standing.

Respiratory Symptoms: Mild cough, sneezing, or sinus swelling (similar to Mycoplasma gallisepticum infection, but usually milder).

Impact on Egg Production:The egg shell quality is reduced (such as thin-shell eggs and sandy-shell eggs), and the egg production rate may be reduced.

Yellow or grayish white viscous exudate can be seen in the joint cavity, and the synovial bursa is thickened and edematous.

Chronic cases may present with articular cartilage erosion or fibrosis.

Prevention Options for Mycoplasma Synoviae Infection

Before introducing breeder hens or chicks, ensure that the source farm is free of MS infection and conduct serological testing (e.g., ELISA) or PCR.
Isolate and observe newly arrived flocks for at least 2 weeks, confirming their health before re-integrating.

Vector Control：

Prevent birds, rats, mosquitoes and flies, and avoid mechanical transmission of pathogens.

Personnel and Equipment Control：

Strictly limit the movement of people within the facility, and disinfection (such as changing shoes and clothes and washing hands) is required upon entry and exit.
Shared equipment (egg baskets, feed carts, etc.) must be thoroughly cleaned and disinfected.

Immunization Management：

Vaccination: Use an inactivated MS vaccine (such as the MS-H strain) for chicks, initially administered between 1 and 3 days of age, followed by a booster vaccination 2 to 3 weeks later. Layers or breeders can be vaccinated again before laying to reduce the risk of vertical transmission.

Immune Boosting: Add vitamins A, C, and E or beta-glucan to boost the flock's immunity.

Treatment Regimen for Mycoplasma Synovitis
Antibiotic Treatment
Supplement with vitamins A, D₃, E, and selenium to promote the repair of mucous membranes and joints.
Add electrolytes (such as oral rehydration salts) to relieve stress.

Combination Treatment for Secondary Infection

1.Secondary bacterial infections (such as E. coli and Staphylococcus): Tiamulin/Tylosin + Florfenicol
Tiamulin (0.025%-0.05% in drinking water) or Tylosin (50-100 mg/kg feed) controls mycoplasma.
Florfenicol (20-30 mg/kg body weight) targets Gram-negative bacteria (such as E. coli).
Course duration: 5-7 days.