Mycoplasma gallisepticum - CRD in chickens and infectious sinusitis of Turkeys Mycoplasma synovium – synovitis Chronic respiratory disease Also known as infectious air sacculitis in chickens Characterized by respiratory rales, coughing, nasal discharge, and conjunctivitis, and frequently in turkeys, infraorbital sinusitis. Prolonged respiratory signs in a flock Occurrence World wide Affects all age groups It is one of the economically significant disease that cause serious losses in poultry farms

1. Course: Poultry Diseases
Dr. Mohamed Abdi
Department of Veterinary Medicine
Feb, 2024
Gollis University

2. Avian mycoplasmoses
Mycoplasma gallisepticum - CRD in chickens and infectious sinusitis of
Turkeys
Mycoplasma synovium – synovitis
Chronic respiratory disease
Also known as infectious air sacculitis in chickens
Characterized by respiratory rales, coughing, nasal discharge, and
conjunctivitis, and frequently in turkeys, infraorbital sinusitis.
Prolonged respiratory signs in a flock
Occurrence
World wide
Affects all age groups
It is one of the economically significant disease that cause serious
losses in poultry farms

3. Etiology
Mycoplasma gallisepticum
is a pathogenic species within the genus Mycoplasma of the
family Mycoplasmataceae
M. gallisepticum stains well with Giemsa and is weakly
gram-negative. By light microscopy, organisms generally
appear coccoid
It may be associated with other agents like E. coli, NCD, IC,
fowl cholera etc.

4. Predisposing factors
Stress conditions like ammonia dust, inadequate ventilation
or over crowding plays an important role in the incidence
and severity of CRD.
Transmission
Horizontal transmission occurs readily by direct or indirect contact
M. gallisepticum seldom survives for more than a few days outside
of a host, so carrier birds are essential to the epidemiology of
disease.
widespread disease outbreaks may occur via fomites:
contaminated airborne dust, droplets, or feathers
Vertical or trans-ovarian transmission

5. Clinical signs
Mainly respiratory signs
Coughing, sneezing
Nasal and ocular discharge
Respiratory rales
Incase of layers decrease in egg production
In broilers decreased rate of growth

6. Lesions
Because of prolonged course affected birds have emaciated
carcass
Gross lesions consist primarily of catarrhal exudates in nasal
and paranasal passages, trachea, bronchi, and air sacs.
Air sacs frequently contain caseous exudates
In severe cases of typical air sac disease in chickens or
turkeys
airsacculitis, fibrinous or fibrinopurulent perihepatitis, and
adhesive pericarditis resulting in high mortality and extensive
condemnations at processing.

7. Diagnosis
History – specially management conditions related to stress
factors (overcrowding & ammonia )
Clinical signs and lesions
Serological test can be employed (serum plate agglutination
test)
HI, ELISA
Confirmation by isolation and identification of the agent

8. Differential diagnosis
Newcastle disease
Infectious bronchitis
E coli infection
Infectious coryza
Fowl cholera
TB

9. Control
Antibiotic (tylosine)
Mycoplsma free chicken introduction and rearing them with
adequate biosecurity
Avoiding stress factors
Regular testing
Vaccination