Mycoplasmoses
Two of the established pathogens for domestic fowl
out of the 17 named species are
g
Mycoplasma gallisepticum.
g
Mycoplasma synoviae
Mycoplasma Gallisepticum Infection
Causative agent – Mycoplasma gallisepticum.
Transmission
g
Direct contact of
susceptible birds with carriers.
g
Also spread by
air borne dust or droplets.
g
It is vertically
transmitted.
Signs
g
Tracheal rales.
g
Nasal discharges
and coughing.
g
Reduced feed
consumption.
g
Birds lose
weight.
g
Decreased egg
production.
g
Disease is more
severe in cold season.
g
Broilers-suffer
mostly between 4 to 7 week of age.
g
In broilers the
respiratory signs are more marked than layer flocks.
g
Sinusitis,
conjunctivitis, with inflammation of one or both the eyes.
Gross Lesions
g
Catarrhal
exudates in the nasal and paranasal passage, trachea, bronchi and airsacs.
g
Oedema of
airsacs.
g In severe and
complicated cases with. E.coli there is fibrinous Perihepatitis and
pericarditis along with massive airsacculitis.
Histopathology
g
Thickening of
tracheal mucosa due to hyperplasia.
g All the alveoli
and bronchioles are filled with purulent exudates comprising chiefly of
polymorphs and mononuclear cells with extensive congestion and haemorrhages.
g Alveoli and
bronchioles are filled with purulent exudates with infiltration of heterophils
and presence of caseation.
g
Thickening and
hyperplasia of the tracheal mucosa with oedema and infiltration of few
mononuclear cells.
g Lung parenchyma
is filled completely with heterophils and mononuclear cells with presence of
haemorrhages.
g Lymphofollicular
reaction in the lung parenchyma with haemorrhages.
Diagnosis
g
Isolation and
identification of causative organism.
g
Serology by
ElISA.
g
Mycoplasmoses
must be differentiated from other respiratory infections like Newcastle
disease. Infectious bronchitis, Fowl cholera and Coryza.
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