External parasites in poultry

The main external parasites that are problematic for poultry are mites and lice. Mite parasites feed on the blood of chickens and can cause anaemia and possible death, while lice feed on dander and feathers. The red mite causes the most problems in poultry.

Distribution

Found throughout Australia.

The red mite (Demanyssus gallinae) is more active during the summer months and is more prevalent in warmer climates.

Life cycle

Mites

Mites feed on chickens during the night and then hide in cracks, under perches and nest boxes during the day. The life cycle of the mite from egg to adult is 7 days.

Lice

Many different types of lice live on poultry and remain on the bird throughout their entire life. Eggs (nits) are laid in clusters at the base of the feather shaft and hatch in 4-7 days. An adult louse will live for about 3 weeks, laying between 50-300 eggs.

Affected animals

  • poultry
  • chickens

Symptoms

Mites

  • Skin irritation and restlessness in birds
  • Darkened or dirty feather appearance
  • Drop in egg production
  • Pale comb and wattle
  • Anaemia
  • Visual – scabs or mites present around the vent, the breast, under wings and scaly legs
  • Large numbers can cause deaths

Lice

  • Feather damage and loss due to itching and irritation
  • Dull appearance
  • Often found around the vent area
  • Mass of lice eggs at the base of the feather shaft

Impacts

Mites

Red mite may transmit other poultry diseases such as fowl cholera. The skin irritation of birds may also possibly lead to feather pecking. In severe mite infestations, egg production is reduced and birds will suffer from anaemia.

Lice

Skin irritations caused by heavy infestations of lice may be the source of secondary infections.

How it is spread

External parasites are mostly spread by bird to bird contact. Wild birds and rodents may also be responsible for parasites entering the flock. Once detected, it is highly likely that all birds and housing are infected.

Control

Prevention and early detection are the best ways to deal with mites and lice. Regularly check birds for signs of mite and lice and check common hiding places such as under perches and in cracks. Keep coops clean and dry and where possible allow birds to dust bath. Once mites and lice are in your flock, they can be difficult to control.

Thoroughly clean and sanitise housing between flocks, paying particular attention to treat:

  • all cracks and crevices
  • along the edge of the housing where the floor meets the wall
  • under perches and nest boxes.

Check with your veterinarian about which products are registered for the control of external parasites on poultry and always adhere to directions.

Quarantine

New birds entering the flock should be quarantined for at least 2 weeks to be sure they do not bring lice or mites into the current flock. Check new birds regularly for any signs of infection.