Most of us are familiar with the parasites that affect dogs and cats, but what some people don’t know is that parasites are a common problem in poultry as well. It’s essential to be familiar with which parasites affect birds, so we can be vigilant and protect our flocks.

What are parasites?

A parasite is an organism that lives in or on an organism of another species (also known as a host). These parasites benefit from the host by getting food at the host’s expense. There are internal and external parasites that affect our feathered friends. Internal parasites live inside the body and can affect organs and body systems, like the intestinal tract (gut). External parasites live on the outside of the bird and will usually affect their feathers and skin.

 

Common External Parasites:

Fleas

    • Found on 20% backyard flocks visited in a study conducted in 2015 
    • Small (1.4-4 mm long), reddish-brown to black, wingless, blood-sucking insects
    • Embed their heads into the skin of areas without thick feathers and feed on blood for up to 19 days
    • Commonly found on face, around eyes, comb & wattle
    • Common fleas in chicken:
      • Sticktight flea (Echidnophaga gallinacean)
      • European chicken flea (Ceratophyllus gallinae)

Lice 

    • Vary in size and color but are usually visible to the naked eye. 
    • Live their entire life cycle on the host.
    • Feed mainly on the skin, feathers (pin/quill) and, while they’re not blood-sucking parasites, they can also feed on the blood inside the feathers.
    • Did you know? We can usually have a good idea of which type of louse is affecting the bird depending on which area of the body it is found.  Different species of lice infect different areas of the body.
    • Common lice in chicken:
      • Chicken body louse (Menacanthus stramineus) 
      • Feather and shaft louse (Menopon gallinae)
      • Head and neck louse (Culclotogaster heterographa)

Mites 

    • Very common 
    • Smaller than lice 
    • Feed on blood, feathers or skin 
    • Common mites in chicken:
      • Red mite (Dermanyssus gallinae) is a blood-sucking mite. It is different than most because it feeds at night and it spends the rest of its time hiding and laying eggs in the environment (cracks, crevices, roosts of the chicken house, etc.). Because they’re not consistently on the birds, it can be challenging to diagnose them.
      • Northern Fowl Mite (Ornithonyssus sylvarum) is also a blood-sucking mite, but unlike the red mite, it spends its whole life on the host. You can find these guys by parting the feathers in the vent, tail, and breast area (Shown in picture below) 

Northern Fowl Mite (Ornithonyssus sylviarum) is a common external parasite of both domestic fowl and wild birds

Common Internal Parasites:

Roundworm (Ascaridia galli)  

    • A nematode that resides in the small intestines
    • Commonly affects young birds (<3months)  

Coccidia 

    • Protozoan parasite (Eimeria spp)
    • Affects different parts of the intestinal tract of poultry 
    • Species specific: This means that the coccidia that infect chickens don’t infect turkeys and vice versa
    • Generally seen in young birds (1 – 4months)
    • Vaccine-preventable: there is a coccidia vaccine available for chicks. Check to see if your hatchery has vaccinated chicks prior to purchasing.

 

Other Frequently Asked Questions:

How does my chicken get parasites?

Mites and lice can infect your flock in direct and indirect ways.  Equipment like egg flats, crates, and coops can be contaminated with parasites, and can bring parasites to your flock. Alternatively, parasites can be spread when personnel go from house to house or farm to farm without practicing proper biosecurity. Your chicken can also get parasites if it comes into direct contact with another infected bird, wild birds, or other animals or wildlife.

Chickens can get roundworms from exposure to contaminated flies or soil that is infected with the eggs from this parasite. Coccidia can thrive in a moist, heavily soiled litter, and chickens can get it by ingesting infected oocysts (egg-like stage of the parasite). 

 

How will these parasites affect my chickens?

When blood-sucking mites feed on your chicken, your birds may suffer from blood loss over time. When your bird doesn’t have enough blood, they can quickly become weak or die, because blood is what carries oxygen and other important nutrients around the body! 

Mites and lice can cause feather loss or scabs, and when your bird has a lot of small, open wounds, bacteria can settle in and cause additional “secondary” skin infections. A hen that is infected with mites or lice may lay fewer eggs. If you are breeding her, she may have trouble having healthy chicks. Know that lice will most severely impact birds that are weak or young. 

Parasites that infect your chicken’s gut can cause diarrhea that may or may not be bloody. You’ll also notice weight loss, decreases in activity, changes in behavior, slower growth or even death.

Female vet Holding Chicken

What can I do?

  • Check your flock periodically for external parasites; particularly the face, feather-free areas,  around the back-end (vent) and under the wings. Doing this can reveal eggs or moving lice on the skin or feathers 
  • Isolate and evaluate new birds for such parasites and other illnesses before introducing them to your flock. 
  • Make sure to clean your coop at least once a week. By doing this, we can help remove parasites in the environment 
  • Prevent other birds from direct contact with your chickens 
  • Ask your veterinarian about routine yearly fecal exams

 

What about treatment?

  • The best approach is to follow your veterinarian’s advice for treatment or preventative measures against parasites.
  • Laws surrounding which pesticides are approved for use can change, and are unique to the state you live in. Check with your local agriculture commissioner regarding what pest control is approved for use, or ask a vet.
  • Pesticides are generally available as dusts, wettable powders, liquid sprays, and resin strips
    • Dusts and sprays should be applied directly to the chicken’s skin. Either part the feathers to reach the skin or use a spray that has enough pressure to get to the skin through the feathers. Spray from above and below. For poultry kept on litter you can use a dusting box for periodic treatment (once every 4 weeks). 
    • To control mites, you’ll also need to apply sprays to litter, bedding, and structures to kill mites that are hiding. Use a liquid spray for structures and ensure you get into cracks and crevices. 
    • Resin strips can be placed into poultry cages or nest boxes for continuous control. Place them in areas where birds regularly go, like food and water sources or roosting sites. Only use the strips during mite/lice season, otherwise pests can develop a resistance to it, meaning the product won’t work anymore over time! 
  • Always follow your vet’s instructions and the instructions on the pesticide label! 
  • There may be a mandated withdrawal period associated with the treatment of choice. This means that you may have to wait a given number of days or weeks after treatment to use and/or sell any meat or eggs from that bird. Read the label for this information, ask your veterinarian, or check with the association or agency overseeing your sales location.

Many types of parasites can affect your flock. If you suspect your bird has parasites, it is best to discuss it with your veterinarian.  An exam and accurate diagnosis will ensure your birds will receive the right treatment. Remember that these parasites can be very contagious, so early treatment can help prevent a significant outbreak.