Disease sheet · NEXTEKCI School
Marek’s disease
A viral disease causing paralysis and tumours. The virus spreads through feather dust and stays in the house for a long time. There is no cure: protection relies on vaccinating chicks very young and on hygiene.
Type
virus
Severity
serious
Who is affected
Mainly birds kept for a long time: layers, pullets, coloured chickens.
Most affected age
Mainly in birds over 6 weeks of age.
Signs to look for
- •Paralysis of a leg or wing; bird sitting with one leg stretched forward and the other backward.
- •Gradual weight loss despite eating.
- •Grey eye, misshapen pupil, loss of sight.
- •Mortality that drags on over time rather than a sudden peak.
- •In layers: disappointing production and birds wasting away.
How it spreads
- •Feather dust from infected birds, which remains infectious in the house for a long time.
- •Mixed ages on the farm: young birds are infected by older ones.
- •Dust carried on clothing, boots and equipment.
Not to be confused with
- •Newcastle disease (nervous form)
- •Feed deficiencies (leg problems)
- •Lameness and leg disorders
Prevention
- •Brown laying chicks are vaccinated against Marek’s disease at the hatchery (certificate on request). The other chicks (white broilers, red broilers, barred grey, hybrids, cockerels) receive no vaccine at the hatchery: vaccination is done on the farm, following the protocol of the vet in your area.
- •Single-age flock: do not mix birds of different ages.
- •Careful removal of dust (beams, wire mesh, low walls) between flocks, followed by downtime.
- •Boots and clothing kept to each house.
What to do if you suspect it
- •Isolate sick birds.
- •Call the vet in your area: only an examination or post-mortem confirms the disease.
- •Do not sell sick birds.
- •Record age, number of cases and how they evolve on the record sheet.
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.