By Linnea M. Tracy, VMD, MPH, MAM, DACPV
Mites
Parasite awareness isn’t just for mammalian patients! As more backyard chicken flocks pop up across Pennsylvania, there’s no better time to refresh your knowledge of the little organisms that can be a big headache for birds. Parasitism contributes to decreased egg production, weight loss, behavioral issues, feather loss, and physical discomfort. If you don’t regularly see poultry in practice or have been lucky enough to avoid these creepy critters since the North American Veterinary Licensing Examination, here’s a quick refresher of just a few common chicken parasites for your small flock practice.
Northern fowl mites, Ornithonyssus sylviarum, are the mites of greatest concern for most North American flocks. These hematophagous mites spend their entire lives on hens, so the best control strategy is to treat birds directly. If you suspect Northern fowl mites, check the area around the vent for erythema and scabs. You might notice that vent feathers are dirty from mite excreta, and you may even see some of the tiny, brown culprits scurry for shelter under feathers.
Tip-Offs Chickens, like other birds, are careful not to betray illness or infestation. Any of the following subtle signs should prompt further investigation in flocks, as parasites could be a cause: •
Behavior changes—increased anxiety, flightiness, increased vocalization, pecking self or others, depression.
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Production changes—consistently decreased egg production or weight loss.
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Changes in appearance—feather loss; reddened, scabbing areas around the vent or under the wings; thickening or raising of leg scales; poor feather condition; comb or wattle pallor; excreta adhered to feathers; loose or bloody stool; abnormally wet litter.
The key to mite control is prevention! Exclude wild birds from your coop to prevent introduction and keep your coop clean with opportunities for dust bathing. If you must introduce new birds to an established flock, quarantine newcomers for at least 14 days and regularly inspect them for signs of parasites before introducing them to your flock.
ITCH ALERT! Poultry bed bug infestations can cause significant anemia and drops in egg production. While poultry mites only occasionally bite humans, both human and poultry bed bug species can infest people and can be carried home (or accidentally carried into a flock). Keep your coops clean and use designated clothing when tending to your birds!
Pennsylvania Veterinary Medical Association | 13
