Mites, Lice, Worms and Scaly Leg: Parasite Control for a Backyard Flock

A flock that looks perfectly healthy can still be carrying parasites. They steal blood and nutrients, irritate the birds and can cause pale combs, poor laying, weight loss and, in bad infestations, death. The good news is that most parasite problems in small flocks are manageable with regular inspection, a clean coop and early action. The bad news is that waiting until a hen looks terrible usually means the problem has been building for weeks.

This guide explains the usual suspects and the basic approach to dealing with them. It is not a treatment protocol. Products and doses vary, many are not labeled for poultry and some leave residues in eggs and meat, so work with a veterinarian who sees poultry and follow every label. If you want to find poultry health workshops near you, agriculture.directory can help you find agriculture events in your area.

External Parasites

These live on the bird or in its surroundings.

• Red mites. Also called roost mites. They hide in cracks in perches, nest boxes and walls during the day and come out at night to feed on roosting birds. Signs include restless hens at night, hens that avoid the coop or nest boxes, pale combs, and gray or reddish specks along perch ends. They are more of a coop problem than a bird problem.
• Northern fowl mites. These live on the birds themselves, especially around the vent, and can cause dark, dirty-looking feathers and scabby skin. They are often found in cooler weather.
• Lice. Chewing lice live on the skin and feathers, feeding on skin debris and feather parts. Part the feathers near the vent and under the wings and look for small, fast-moving insects and clusters of eggs at the base of feathers.
• Scaly leg mites. These burrow under the scales on the legs and feet, causing raised, crusty scales that can become painful and deform the legs if untreated.

Internal Parasites

Worms live in the gut or respiratory tract. Roundworms and tapeworms are the common intestinal ones, and gapeworms live in the windpipe and cause gaping and coughing in some birds. Coccidia are microscopic protozoa that damage the gut lining, especially in chicks, and can cause bloody or loose droppings. Signs of heavy worm burdens include weight loss, poor feather condition, drop in laying, pale comb and diarrhea. A flock on pasture or on soil that has been used for years has a higher chance of picking up worms from droppings. A veterinary fecal test can identify what is present and whether treatment is needed. The Merck Veterinary Manual poultry section describes the parasites of poultry.

Check Your Birds Regularly

1. Handle each bird. Once a month, or whenever a bird looks off, hold her and look at the comb, skin, vent and feathers.
2. Look under the wings and around the vent. Part the feathers and look at the skin.
3. Check legs and feet. Look for raised or crusty scales.
4. Inspect the coop at night. Go out with a flashlight an hour or two after dark and look at roosts and cracks for mites.
5. Wipe a white cloth or tissue along perches. Smears of blood or specks may show mites.
6. Watch droppings and behavior. A bird that is thin, pale or off her food needs a closer look.

Keep a record. Our guide to backyard flock biosecurity covers quarantine for new birds, which is a main way parasites arrive.

Prevention Comes First

• Keep the coop clean and dry. Wet bedding favors parasites and disease. See the guide to bedding and cleaning.
• Design the coop to be cleaned. Smooth surfaces, removable perches and few cracks help. Our coop design guide covers this.
• Give a dust bath. Dusting is natural parasite control, and a dry, sheltered spot with dirt or sand lets birds do it.
• Do not overcrowd. Crowding spreads parasites and stress.
• Quarantine new birds for several weeks before mixing.
• Keep wild birds and rodents out of feed and coops, since they carry mites and worms.
• Rotate or rest ground where birds range, and avoid letting droppings build up.

Treating Mites and Lice

Treatment of the coop is as important as treatment of the birds. For red mites, the coop must be emptied, scrubbed and treated, with attention to cracks and perch ends, and the treatment repeated according to the product directions to catch hatching mites. Birds with northern fowl mites or lice are treated directly. Product choice matters. Some are approved for poultry and some are not, some are safe around eggs and others require an egg withdrawal period. Poultry extension programs such as Penn State Extension poultry and eXtension's poultry community offer guidance on options, and your veterinarian can advise on safe products for your region.

Treating Scaly Leg

Scaly leg mites progress slowly, so catching them early helps. Treatment generally involves softening the crusts and applying an approved product repeatedly over weeks. Do not pick off scales forcibly, since that can cause bleeding and infection. Ask your veterinarian for current recommendations. Heavy breeds with feathered or heavily scaled legs are not immune, so check legs of every bird, including the Speckled Sussex, whose pale legs show changes clearly.

Worming

Routine worming of every flock on a calendar is not always necessary. Many veterinarians prefer testing droppings and treating only when worm burdens are significant, partly to limit resistance. If you do treat, use a product labeled for chickens or one your vet prescribes, and observe egg and meat withdrawal times. Good hygiene reduces the burden: clean waterers, clean bedding, and rotating ranging areas.

Egg and Meat Safety

Many treatments are not approved for use in laying hens, and some require you to discard eggs for a period. Keep treatment records, including product, dose, date and withdrawal period, especially if you sell eggs. Our guide to selling backyard eggs covers records and rules.

When to Call the Vet

• Several birds are pale, thin or dying.
• Droppings are bloody.
• Birds are gasping, gaping or coughing.
• The flock is losing weight despite good feed.
• You are unsure what you are seeing.

Parasites can make birds more vulnerable to other diseases. Rapid decline in several birds may mean something other than parasites, and sudden deaths should be reported to your state animal health officials. The USDA Defend the Flock program explains how, and the CDC backyard poultry guidance covers hygiene when handling birds.

Common Mistakes

• Treating the birds but not the coop. Red mites return from the cracks.
• Using products not labeled for poultry. They may be unsafe or leave residues.
• Worming on a schedule with no testing. It can build resistance.
• Skipping quarantine. New birds bring parasites.
• Never handling the birds. Problems stay hidden.

Farm.fm's page on broiler chickens covers chicken production background, and for a laugh, see farm.fm's piece on farm eggs that finally win employee of the month.