Disease sheet · NEXTEKCI School
Mycoplasmosis
chronic respiratory disease · CRD · Mycoplasma gallisepticum (MG)
A slow bacterial respiratory disease: the flock does not die suddenly, it lingers, coughs and grows poorly. It becomes much worse with ammonia, dust, cool nights and other respiratory infections. It can pass through the egg: hence the importance of buying chicks from a licensed hatchery.
Type
bacterium
Severity
moderate
Who is affected
Broilers, coloured chickens, pullets and layers.
Most affected age
All ages; often visible from a few weeks old, when the house environment deteriorates.
Signs to look for
- •Rattling, especially at night; coughing, sneezing.
- •Nasal discharge, watery or foamy eyes.
- •Swollen sinuses under the eyes.
- •Flock eating less, growing poorly and becoming uneven.
- •In layers: production below expectations.
- •Slow course, over weeks.
How it spreads
- •From bird to bird, through the air and nasal discharge.
- •Through the egg, from hen to chick.
- •Mixed ages and introduction of birds from elsewhere.
- •Equipment, crates and people moving between farms.
Not to be confused with
- •Infectious bronchitis
- •Infectious coryza
- •Colibacillosis
- •Irritation from ammonia and dust
Prevention
- •Chicks bought from a licensed hatchery.
- •Dry litter, good ventilation without draughts on the birds, no ammonia.
- •Single-age flock: no mixing of ages, no birds brought in from elsewhere.
- •Correct stocking density; curtains closed on cool nights.
- •Biosecurity at the farm entrance and at each house.
What to do if you suspect it
- •Call the vet in your area: any treatment is given only on their prescription.
- •Correct the environment straight away: litter, ventilation, density, night conditions.
- •If a treatment is prescribed, respect the withdrawal period for birds and eggs.
- •Do not introduce new birds into the flock.
This sheet helps you recognise the disease and react quickly. It does not replace the veterinarian: only they can diagnose and prescribe a treatment. Worried about your flock? Write to us on WhatsApp at +225 05 44 83 27 79.