External Parasites and Lice
Poultry Farming in South Africa

© Roger de la Harpe

In the past, farmers might not have been too worried about external parasites, such as lice, mites, ticks, fleas and flies. However, these pests feed on the blood of birds and by doing so not only cause discomfort, but also have a negative impact on bird health, growth and egg production. In extreme cases it may even lead to the death of birds, with especially chicks and stressed birds being vulnerable.
Birds typically get infested when they get into contact with other infested animals, such as rodents or other birds, or equipment, such as crates. With intensive production systems – where many birds are kept together – farmers have to be especially vigilant, as infestations can spread like wildfire. Farmers who keep free-range or scavenging birds should, nevertheless, regularly inspect birds to identify problems before they get out of hand.


Avian lice are species-specific, feeding on bits of skin or feather products, so won’t last long on people or mammals. They can nevertheless still bite you, leaving itchy red marks, so it is best to wear protective clothing and gloves while treating birds for this pest.
What do they look like?
Various species exist, each with their own preference for a specific area on the bird, from the feathers to the wings, body or head. They are typically 2 mm to 5 mm long, wingless, six legged, flat and range from light yellow to brown in colour. Nits or eggs might be greyish-white to straw-coloured and are laid in clusters.

Signs of infestation?

Birds with lice will look bedraggled and dull. Their feathers might be ruffled and fall out and they will be uncomfortable, scratching and pecking at themselves in search of relief. Skin irritations may turn into secondary bacterial infections.
Heavy infestations will have a negative impact on the reproductive potential of male birds, egg production in females and weight gain of chicks. It may also lead to the death of especially young chicks.

By Glenneis Kriel