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Q: Mycoplasma Overview


Mycoplasmas Also called
Therer are several mycoplasmas, which are variously known as mycoplasma Gallisepticum, mycoplasma Synoviae, MG, Chronic Respiratory Disease, Infectious sinusitis (in turkeys)

Common in large commercial laying or meat flocks, more common where air quality is poor

General signs -
No or mild signs in adult birds, including lethargy, loss of appetite, drop in laying, yellow poo, wheezing, coughing, sneezing, discharge from nares or eyes, orswollen wings or hocks. It causes death in chicks at a much higher rate, and also causes slowed growth, stunting and other problems.
Cardinal or diagnostic signs -
Must be diagnosed in the laboratory.

Cause/s -
Bacterial - Mycoplasma gallisepticum or Mycoplasma synoviae

Communicability -
Yes. It is very contagious and can be passed from bird to bird like most respiratory diseases can. It can also be passed in ovo from mother to chicks, and can be carried in on shoes or equipment, or inhaled in dust. Wild birds such as house finches can suffer from (and spread) this illness.

Communicability to humans -

Incubation period -
4 - 21 days

Yes. Chickens who survive this mild illness become symptom-less carriers.

Yes. It is carried by wild birds.

Home treatment and/or prevention -
Prevention: Practice good biosecurity, and purchase only from NPIP flocks. This goes for hatching eggs, too, since the illness can be passed in ovo from hen to chick. Even the recommended 30 day quarantine when adding new birds to your flock will not protect your flock from MG if the new bird or birds being introduced are symptomless carriers. Some vaccines (F-strain) can spread the disease to turkeys or other poultry, while others (ts-11 and 6/85) are safer. Attenuated vaccines made from dead virus are safer because they do not spread. Because some MG vaccines are unsafe and spread the disease, in some states all vaccines for MG are illegal out of concern for turkey flocks (it is a much more serious disease in turkeys).

Treatment: In chickens, the disease is usually mild, but no treatment can prevent survivors from becoming carriers for life. This will reduce laying, make it difficult to hatch live chicks, make any chicks that hatch at risk for dying from MG. Any that don’t die will be slow to mature and have reduced laying for life… and pass the problem on to their progeny. In addition, MG can make your birds more vulnerable to other serious illnesses like e.coli or Newcastle. Veterinary care -Some antibiotics can help reduce symptoms, but survivors are still carriers. Contact your veterinarian for more information.

Recovery - AS described above, MG is usually mild in adult birds, however it will reduce laying and will be passed from hen to chick through the egg.

Other conditions, illnesses and/or diseases with similar signs:
Other respiratory illnesses can be easily mistaken for MG, including infectious bronchitis, Newcastle, influenza, and coryza.

Also consider browsing through this list of other chicken illnesses with respiratory symptoms.

This is a reportable disease.