What is Mycoplasma synoviae

Chicken synoviae Mycoplasma is an uncommon disease that many people may not have heard of. It is an animal disease and also an infectious disease. Generally speaking, it mainly targets young chickens and turkeys. Its symptoms include swollen joints and muscle inflammation. Because it is an infectious disease, it must be treated in time to avoid expanding the scope. But for most people, they may not know what it is?

1. Distribution hazards

Because the disease develops slowly and has a long course, once it is infected in the chicken flock, it is difficult to eradicate. Therefore, it spreads in the chicken flock for a long time, resulting in low feed utilization, slow growth and development, increased culling rate, and decreased egg production. If this pathogen exists in the chicken flock, mixed infection is likely to occur, aggravating the disease, increasing the mortality rate and causing serious economic losses. [1]

2. Disease Pathogen

MS stains well with Giemsa and is Gram-negative. In the stained specimens, it appears as a pleomorphic spheroid or rod-shaped body, about 0.2 μm in diameter and 0.4 μm in length. Under an electron microscope, the shapes are different, some are round and some are filamentous. Serum and nicotinamide adenine dinucleotide must be added during culture. After 3-7 days of culture, raised, round, slightly lattice-shaped, center-bearing or center-less colonies with a diameter of 1-3 mm will be formed. The optimum growth temperature is 37℃.

3. Clinical symptoms

Chickens over 12 weeks old rarely get sick. The most common disease occurs in chickens aged 9-12 weeks, with an incidence rate of 5%-10%. The mortality rate is generally less than 10%, and in severe cases it can be as high as 75%. The combs of sick chickens are shrunken and white, they withdraw from the group, like to lie down, shrink their heads and close their eyes, grow slowly, have rough and messy feathers, walk with a slight figure-eight gait, limp, and are anemic. Green stool, ascites, and weight loss. There is often swelling around the joints, especially the hocks and metatarsals, which can sometimes be as big as a pigeon egg and feel fluctuating when touched. In the later stages of the disease, joints become deformed, the patient becomes bedridden for a long time, and although he still has an appetite, he becomes extremely emaciated due to the inability to eat. Finally, he dies from exhaustion or complications of other diseases. Egg production in hens can drop by 20%-30%.

4. Pathological changes

During autopsy, most patients in the early stages of the disease showed obvious swelling in the joints and tendon sheaths, and the presence of a sticky, creamy to grayish white exudate. In patients with a long course of illness, the exudate is cheesy, and the surface of the infected joint is often yellow or orange-red. The characteristic amount of exudate is larger in the tarsal joints, wing joints or foot pads, the joint membrane is thickened, and the joints are swollen and prominent.

Pathological examination: Heterophilic leukocytes and fibrin infiltration can be seen in the joints, especially in the joint cavities and tendon sheaths of the toe joints and tarsal joints. The synovial bursa proliferates with villus formation and nodular infiltration of lymphocytes and macrophages in the subsynovial layer.