Why Parasites Are a Fact of Life in the Garden Flock

Keeping a few hens at the bottom of the garden is one of life's genuine pleasures, but it does come with a hidden cast of characters. Red mites, lice, and internal worms are the three you'll meet most often, and every keeper will deal with at least one of them eventually. The good news is that none of them are a disaster if you catch them early. The trouble starts when an infestation is allowed to build quietly through spring and summer, sapping your birds' strength before you've noticed anything amiss.

This guide walks you through what to look for, how to confirm your suspicions, and which treatments are both effective and safe for a small domestic flock. It's written with the British climate in mind, because our damp, mild summers are sadly ideal for parasite life cycles.

Red Mite: The Night-Time Nuisance

Red mite (Dermanyssus gallinae) is the parasite that keeps poultry keepers awake at night, quite literally. These tiny grey mites live in the cracks and crevices of the coop rather than on the bird itself, emerging in darkness to feed on blood. After feeding they turn a telltale reddish-brown, which is where the name comes from.

Signs to watch for:

• Hens reluctant to go into the coop at dusk, or refusing to roost and instead sleeping on the floor or in the run
• Pale combs and wattles, listlessness, and a slow drop in egg production
• Small dark smudges on eggshells or perches, which are mite droppings
• Bites or scabs on your own arms after handling the birds or cleaning out the coop

To confirm, run a piece of white kitchen roll along the underside of perches and into the joints of the housing, ideally at night. If you see grey or red specks moving, you have your answer. Treatment means treating both the birds and the housing. For the coop, strip everything out, scrub with a suitable poultry-safe detergent, and apply a licensed acaricide, paying particular attention to cracks and perch ends. Diatomaceous earth can help as a barrier in dry conditions but won't clear an established infestation alone. For the hens themselves, a veterinary-recommended spot-on or powder will help break the cycle. Repeat treatment after around seven days, as eggs left behind will hatch into a fresh generation.

Worms: The Invisible Drain

Internal parasites are easy to overlook because the signs are subtle. The most common in garden flocks are roundworm and, particularly on grass runs, hairworm (capillaria). A light worm burden is often tolerated, but a heavy one will drain condition, reduce laying, and leave birds vulnerable to other problems.

Things that should raise suspicion:

• Pale, sometimes foamy or loose droppings
• Weight loss despite a good appetite, and a dull, hunched posture
• Eggs with pale yolks, soft shells, or a sudden drop in output
• Visible worms in droppings, though absence proves nothing

A worm egg count through a vet or a postal faecal testing service is well worth the small fee, as it tells you exactly what you're dealing with and whether treatment is needed. For a confirmed burden, a licensed poultry wormer such as flubendazole is the standard choice, given in the feed over several days. Importantly, there is an egg withdrawal period, so check the packet carefully and don't eat or sell eggs during that window. Many keepers worm routinely in spring and autumn, but over-treating encourages resistance, so testing first is the better habit.

Lice and Scaly Leg Mite

Lice are the parasites you can actually see. They're pale, flat, and fast-moving, and they live on the bird, clustering around the vent and under the wings, where they glue their eggs in clumps to the base of feather shafts. An affected hen may be restless, peck at herself, and develop a scruffy rear end from broken feathers and constant preening.

Treatment is straightforward. A licensed poultry powder containing a suitable insecticide, dusted onto the skin, usually needs repeating after a week to catch newly hatched lice. Treat every bird in the flock, not just the itchy one, and give the coop a thorough clean at the same time.

Scaly leg mite is a different beast altogether, burrowing under the leg scales and causing them to lift and crust. You'll spot it as raised, rough, greyish scales, sometimes with swelling or lameness. A traditional and effective approach is to apply a thick barrier such as petroleum jelly or an oil-based preparation to the legs weekly, which smothers the mites. Persistence over several weeks is key, and badly affected scales may take months to shed and regrow.

Prevention: The Best Treatment of All

Cleanliness does more than any single product. A coop that's dry, well-ventilated, and easy to clean is a hostile place for parasites. Line floors with removable material, use perches you can lift out, and keep wild bird feeders well away from the run, as they can bring in lice and disease.

• Clean the coop weekly and do a deep clean each season
• Use a poultry-safe disinfectant rather than household bleach
• Inspect your birds at least monthly, especially around the vent and legs
• Rotate grazing areas if possible and keep grass short around the run
• Quarantine any new bird for a fortnight before introducing it to the flock

Watch your hens closely and get to know what "normal" looks like, because you'll spot trouble days before it becomes serious. A ragged-looking hen that's off her food is telling you something, and a torch and a quick check of the coop perches will usually tell you what.

Finally, a word on products. Always choose something licensed for poultry, and follow the label exactly, particularly where egg withdrawal is specified. If you're unsure, your vet is the best port of call, and many now offer poultry advice even for small backyard flocks. Handled early and sensibly, parasites are a manageable part of the hobby rather than a reason to give it up.