External Parasites

External Parasites

Reading Time: 5 minutes

by Kristi Cook Chickens are relatively simple creatures to care for: provide adequate shelter, a bit of food and water, et voila! eggs and chicken for dinner. However, despite our best efforts, sometimes danger creeps into the coop and threatens the health and productivity of our flocks. I’m not talking opossums and raccoons but external parasites such as lice and mites, who enjoy a chicken meal just as their mammalian counterparts do. And just as ‘coons and ‘possums threaten overall flock productivity, so do these nasty creepy crawlies as they suck, chew, and bite their chicken host to their hearts’ content. Protecting your flock from these tiny parasites can be a simple matter of pest awareness and prevention.  

Mites and Lice 

Both mites and lice cause significant loss in the poultry industry through their biting, sucking, and chewing activities. When allowed to multiply unchecked, these external parasites not only reduce egg production in layers and overall carcass weight-loss in meat birds but cause anemia, secondary infections, and even rapid death. The swiftness with which these parasites can overtake an entire flock is astounding, so making a positive ID and taking swift action is of paramount importance. 

external-pests
The red poultry mite ( Dermanyssus gallinae) under a microscope

The Mighty Mite 

Of the two external parasites, mites are smaller, making identification more difficult than identifying the larger louse. However, close inspection will reveal dark red, black, or tan specks crawling around the vent area and/or along the body, particularly around feather shafts. Many are so tiny they look like moving pepper flakes. 

Some, such as the northern fowl and scaly leg mites, prefer to remain on their host for their lifetime. The scaly leg mite is so small that identification is based on the clinical signs of infestation rather than seeing the mite itself. This mite gets its name from the damage it causes as it burrows under the leg scales to feast on the tissue underneath. This burrowing causes the scales on the legs to lift, giving the appearance of rough, scaly legs. Legs, feet, and toes become inflamed and painful to the bird resulting in toe deformities and lameness. As the infestation progresses, the loss of toes becomes a concern as blood circulation decreases. However, if treated promptly, legs, toes, and scales often return to normal.  

Other pests, such as the common chicken mite, hide in nooks and crannies of the chicken coop during the day after feasting on their host at night. The nocturnal behavior of the chicken mite necessitates a nighttime coop visit with a flashlight in hand to inspect the flock. But if you can’t visit at night, you may be able to see specks of blood-filled mites crawling along the roost or hiding in nesting boxes during the day.  

external-parasites
Also known as the “chewing lice,” Menoponidae can be found at the base of feathers where they scratch to obtain blood.  

The Lousy Louse 

Lice are much larger than the minuscule mite and spend their entire lives on the host. Species readily found in a chicken flock include the feather louse, shaft louse, wing louse, and even fluff louse, with the chicken body louse being the most common. Lice or nits (empty egg cases) can be discovered by gently brushing feathers back and looking for tan or white lice crawling along the body. You will likely also see eggs, or nits, attached to the base of feathers in clumps.  

An Ounce of Prevention 

As with all pests, prevention is easier than treatment. And while it is true that most flocks harbor a small parasite load, the goal is to keep it small. Key practices for prevention include matching flock size to enclosure size, providing high-quality feed, fresh water, adequate housing, and frequently changing bedding. Another practice is isolating newcomers, assessing their parasite load, and administering any needed treatment before adding those birds to a mite/lice-free flock. Avoiding exposure to wild birds is another way to reduce parasite loads. However, this is not feasible for most backyard flock owners as sparrows and other wild birds naturally visit chicken yards and feed pans. 
 

external-parasites
Dust baths are essential for chicken health.  Whether on the ground or in a tub, have a place where your birds can dust themselves. 


In addition to the practices mentioned above, diatomaceous earth (DE) in the dust bathing area is one of the most commonly touted preventative measures available, though it’s often underutilized. DE punctures the bodies of mites and lice, causing them to dry out and die. By maintaining some level of DE within the bathing area, birds can actively participate in their own parasite prevention program daily. 

Treatment For Birds and Their Homes 

Regardless of preventative measures, there may come a day when treatment is needed, and the best course of action is to work closely with a livestock vet. Treatment options are often the same for both mites and lice regardless of species, so if using a powder, or spray, check the label to determine if it covers all pests present to avoid over application. Look for products that contain Spinosad as the active ingredient. Often recommended by vets, it usually only requires one application to deal with all stages of parasite growth. 

You’ll need to decide whether you are primarily treating the birds, their coop, or both. Chicken mites, for example, do not live on the host, so treatment of the flock’s living area may be all that is required. Other pests, such as the lice and northern fowl mite, require treatment of the bird and housing area. Clean the coop and run thoroughly, removing all the manure, any moldy grain or straw, and cleaning any food and water containers.  

DE works as both a preventative and a treatment option, but like all-natural regimens, will need to be applied more than once to kill living external parasites and their eggs. Keep examining your birds and treat again as needed.  

External parasites will always be a concern for any flock owner, just as internal parasites and predators are a concern. However, preventative practices such as frequent flock inspections, DE, low stock levels, and clean bedding are just a few of the measures one can take to keep these nasty pests at bay. And should the need arise, multiple treatment options exist to help the flock become and stay healthy. So don’t underestimate the threat of these tiny little parasites. Develop a prevention program that keeps your flock healthy and thriving so you can enjoy those chicken and egg dinners for years to come. 

KRISTI COOK lives in Arkansas where every year brings something new to her family’s journey toward a more sustainable lifestyle. She keeps a flock of laying hens, dairy goats, a rapidly growing apiary, a large garden, and more. When she’s not busy with the critters and veggies, you can find her sharing sustainable living skills through her workshops and articles. 

Originally published in the August/September 2022 issue of Backyard Poultry and regularly vetted for accuracy.

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