Poultry External Parasites — Lice and Mites
Poultry lice and mites are extremely common external parasites of chickens. You can spot these critters before they get out of control if you periodically pick up and examine chickens in your flock.
Poultry lice are wingless, straw-colored insects that feed on dry skin scales, scabs, and feathers. A poultry louse spends its entire life on its bird host; if it falls off the bird, it won’t survive long in the environment — maybe a few days. Lice know what they like, and poultry lice like chickens, not people or pets. If a poultry louse climbs on you, it won’t stay long.
Louse infestations are a drag, especially for young chickens, making them jumpy and slow to grow. Fertility and egg production declines for infested adults. The plumage of lousy birds looks patchy and moth-eaten.
Female lice lay their eggs (nits) in clumps on feather shafts. Inspect birds at least twice a month, spreading the feathers in the vent, breast, and thigh areas, looking for nit clumps or pale, scurrying insects. Fall and winter are when most louse infestations are common.
Mites are tiny relatives of ticks and spiders. A long list of mites infest chickens.
Northern fowl mite
The northern fowl mite is a serious pest of poultry, and this mite has also been found scurrying on wild birds, rats, and people. These mites are blood-suckers, and in heavy infestations, they can cause blood loss, stunted growth, decreased egg production, weakness, and even death. They eat anytime, day or night.
The mites congregate in the vent area; feathers there may be blackened by mites and mite excrement. If you pick up and handle a bird with northern fowl mites, the mites climbing your arms and hands may creep you out.
Four main sources can introduce the northern fowl mite to your flock:
To patrol for a northern fowl mite infestation in your flock, pick up and examine the vent areas of several birds every two weeks.
The roost mite, also known as the red mite or chicken mite, is also a blood-sucker that feeds on poultry and wild birds. The roost mite has a different modus operandi, however; it feeds on chickens only at night and hides in the coop, on roosts, or under piles of droppings during the day.
To spot a roost mite infestation, you need to examine birds at night, looking for dark moving specks, or inspect the coop. Roost mites congregate in cracks and crevices inside chicken houses, seen as tiny red or blackish dots clustered together. Another tip-off: Hens may refuse to lay in infested nests.
Roost mites are spread the same way as northern fowl mites: poultry, people, equipment, and wild birds (pigeons, especially). They’re difficult to eradicate from poultry premises, even after the chickens are gone, because roost mites can live for months without eating.
Scaly leg mite
Scaly leg mites spend their entire lives in the skin of their bird hosts, burrowing tunnels under the scales of the legs and sometimes into the skin of the combs and wattles. Crusty scabs and lumps appear on the scales of the legs of older birds. Long-term infestations result in deformed toes and limping. Scaly leg mites are transmitted bird to bird and by contact with an infested bird’s environment.
Scaly leg mites are too small to be seen without a microscope. If you suspect a scaly leg mite infestation, you can scrape crusts from an affected bird’s leg, put the scrapings in a container, and have a veterinarian or diagnostic laboratory examine the sample.
Prevent and treat poultry lice and mites infestations
Lice and mites are born slobs; they like a damp and dirty coop, so general cleanliness can make your coop less hospitable to these unwelcome guests. Here are some additional measures to protect your flock:
Quarantine all new birds for 30 days before letting them meet your flock. Inspect new birds for external parasites at least twice during the quarantine period and treat them if necessary.
Thoroughly clean transport coops after use. You can dislodge hitchhiking pests with a thorough cleaning.
Discourage wild birds from hanging out with your flock. To do so, use bird netting, screened coop windows, or scare tactics.
To control lice or mites, you can treat both the birds and the birds’ environment. Because roost mites spend so much time off the chicken and living in the coop, treating only the birds will fail to eliminate the problem.
If you diagnose poultry lice, northern fowl mite, or roost mites, treat all the birds in the flock at the same time. Isolate any chickens with scaly leg mite from the rest of the flock while they’re being treated.
Be patient, and don’t expect to get the situation under control with one shot; repeated treatments are necessary. Lice and mites can develop resistance to pesticides, so vary your method and alternate treatments.
|Camphor||Scaly leg mite||Chicken’s legs and feet||Ointment|
|Diatomaceous earth (DE)||Lice, northern fowl mite, roost mite||Chicken, coop, dustbath||Powder|
|Garlic juice||Northern fowl mite||Chicken||Spray|
|Ivermectin||Lice, northern fowl mite, roost mite, scaly leg mite||Chicken||By mouth or injection, prescribed by a veterinarian|
|Neem oil||Lice, northern fowl mite, roost mite||Chicken, coop||Spray|
|Petroleum jelly/sulfur mix||Scaly leg mite||Chicken’s legs and feet||Ointment|
|Pyrethrin and permethrin||Lice, northern fowl mite, roost mite||Chicken, coop||Powder, spray, dip|
|Sulfur||Lice, northern fowl mite, roost mite||Chicken, coop, dustbath||Powder, spray|
An easy way to dust birds with a powder-form pesticide (such as permethrin, DE, or sulfur) is to place the powder and the chicken in a garbage bag (leaving the chicken’s head out of the bag!). Hold the bag closed around the chicken’s neck, and shake the bag to distribute the powder all over the chicken’s body.
Or, even easier, let the chickens dust themselves. Build a dustbath box (24 x 24 x 8 inches is a nice size) and fill it with a mix of playground sand and either diatomaceous earth (50:50 sand: DE) or sulfur powder (75:25 sand: sulfur). Sulfur powder, available at garden stores, has especially good residual action against mites and lice.