Depluming Mite and Unexplained Feather Loss

Bare patches are a symptom, not a diagnosis

You notice the first bare patch on a hen at the neck, then another on the vent, and within a month the flock looks scruffy. The birds are not obviously ill. They eat, they walk about and they lay, but the feathers are coming away and the skin underneath looks wrong. The question on every farmer's mind is simple: is this mites, is it the moult, or are the birds pecking each other?

Feather loss has several causes, and some of them look almost identical from a few steps away. A flock can also have more than one cause at once, such as a moult in older hens together with a mite burden picked up from wild birds. Guessing and buying a random spray wastes money and can make the birds worse. A structured check on a few birds will usually narrow the list in one morning.

This article sets out how to tell depluming mites from a moult and from pecking, what else copies the picture, and how to plan treatment with a vet. For the wider picture of how feed and house conditions affect feathering, our guide to poultry feed in Ghana is useful to read alongside this one.

Three causes that look alike from the door

From a distance, a hen that has lost feathers on her neck looks the same whatever the cause. Up close the differences are clear. Depluming mites make the skin itch and scab. A moult removes feathers in a planned sequence and leaves healthy skin. Pecking tears feathers and opens the skin where other birds have worked on the same spot. Keep those three pictures in mind as you examine the flock, because almost every case will fall into one of them, or into a combination.

The mites are tiny, live partly under the skin or in the feather follicle, and feed on the surface layers of skin. They are hard to see with the naked eye and they are most active at night. That is why a daytime walk through the house often misses them, while the birds keep scratching and the feathers keep falling. Many owners only see the mites after the vet takes a skin sample.

A moult is a normal, periodic renewal of feathers, and it comes with less egg laying, a quieter flock and a predictable pattern. Pecking is a behaviour problem, and it spreads through the flock once it starts. Each one needs a different response, so the first decision is to put the birds into the right category.

What depluming mites leave on the skin

The mites usually known as depluming mites belong to a group of burrowing mites that irritate the skin of the head, neck, vent, thighs and sometimes the back. The first sign is itching. A hen scratches with her foot, shakes her head, rubs against the perch and keeps preening the same spot. The skin in that area becomes dry, grey or red, and small scabs form. Over time the skin can thicken and look rough, and the feathers around it break off short or come out in patches.

The most useful test is to part the feathers and look at the skin in good light. Mite-affected skin looks crusted, flaky or scabby, sometimes with a white or grey crust that lifts easily. The feather shafts may be broken at skin level rather than pulled cleanly out. Compare the affected birds with healthy ones in the same house, because a healthy bird should have clean, smooth skin under its feathers.

In a flock with a heavy mite burden, several birds show the signs at once, and the loss spreads over weeks rather than days. Weight loss and a drop in egg production can follow when the birds are kept itchy and restless. This is not a disease to ignore, and it is also not a reason to panic, because the signs are clear enough for a vet to confirm with a sample.

How a moult looks, and how it differs

A moult follows an orderly pattern. Feathers come out roughly in a set order, usually starting at the neck and back and spreading down the body, and the bird keeps her skin healthy throughout. New pin feathers appear in the same areas within a few weeks, and the bird looks progressively more even as the new coat grows in. The skin is clean and not scratched, and the bird is not restless because of itch.

Moulting hens also lay fewer eggs, sometimes much fewer, for a period. They may be quieter and spend more time resting. The loss is usually symmetrical, meaning both sides of the bird are affected similarly, and the feathers come away cleanly with their quills intact. If you pull a few feathers from a moulting hen, the base of the quill is usually firm, with a small bulb and no sign of bleeding.

Older hens in Ghanaian flocks moult at different times depending on age, feed, season and the health of the flock. Our guide to chicken breeds in Ghana is a good place to read about how strains differ, because some lines naturally moult earlier or more heavily than others. A moult that is complete within a normal period and leaves clean skin behind is rarely a problem in itself. If you are thinking of replacing a flock after a long moult, the layer chicks for sale in Ghana page sets out the options before you decide.

How pecking leaves its marks

Pecking is different in both its pattern and its wounds. The feathers are not planed off evenly. They are torn, broken or chewed at the base, and the bare areas are often on the back, the tail, the vent or the head, where a bird in a pen can reach easily. Where the skin has been opened, you will see blood, scabs or raw patches, and other birds in the pen will show interest in the wound. That attraction is what turns a little pecking into a serious problem.

Pecking usually starts in crowded pens, in bright light, when feed is short, or when birds are bored or stressed by heat. One bird may start the trouble and others join in. A dominant hen that picks at the same spot every day will leave a clear pattern of damage, and the bullied bird may hide in a corner. Look for the bird that is always at the back of the pen, because she is often the target.

If you see wounds, separate the injured bird at once, and ask a vet about treatment for the wound. Pecking is controlled by correcting the cause, not by blaming one hen. Our layer egg profit calculator shows why it is worth fixing early, since injured birds lay less and recover slowly, and the broiler profit calculator does the same sum for meat birds.

Other causes that copy the picture

Several other conditions can thin the feathers or cause bare patches, so a clean diagnosis needs more than a single look. Lice feed on feather fragments and skin debris and cause itching and feather damage, particularly around the vent and under the wings. Red mites and northern fowl mites can also cause feather loss and skin irritation, but they behave differently and are found in different places. Fungal skin infections can cause crusty, bare patches, usually with less itching than mites.

Feed problems are a common hidden cause. A ration short of protein or of certain amino acids results in poor feather growth, brittle feathers and slow regrowth after a moult. Salt imbalance and some vitamin deficiencies can also affect the feathers. If the birds have been on a cheap feed or a change of feed recently, mention it to the vet, because it shapes the whole picture.

Heat stress and overcrowding also cause feather loss, especially in the hot months. A flock kept in a hot house with too little space will shed feathers and lose condition. Check the house temperature, the number of birds per square metre and the ventilation before you blame the mites.

Side by side: telling the causes apart

The table sets out the main differences between depluming mites, a moult and pecking. Use it at the pen, one column at a time, and write down which column best matches what you see.

No single column settles the question on its own. A bird with scabs and itch on the neck and a flock that is moulting at the same time may have both, and the vet's sample is what separates them.

A torch check that finds the mites

Mites are most active at night, so the best time to look is after dark, when the birds are roosting. Walk quietly with a torch and pick out three or four birds from different parts of the house. Lift each one gently, part the feathers on the neck, under the wing and around the vent, and look at the skin closely. A hand lens helps if you have one. Note the location, the colour of the skin and any crust, and whether the bird is still scratching when you put her down.

Do the same on the perches and in the nest boxes, looking for small moving specks in the seams and corners. Red mites are easier to find in these places, though depluming mites live mainly on the bird. A white cloth laid on the floor overnight can help you see what falls off the birds and the perches, and what is moving on the cloth in the morning.

A torch check does not confirm a mite diagnosis on its own. The sure test is a skin scraping taken by a vet, which is looked at under a microscope. Take a sample of a bird that is clearly affected, not one that looks healthy, and ask the vet how the sample should be stored and taken to the lab.

Treatment on the bird: what the vet will consider

Treatment for mites must come from a vet who has examined the birds. The vet will choose a product that is registered for poultry, and will give the dose, the method of application and the number of repeat treatments. The treatment may be a spray, a dust or a dip, depending on the product and the size of the flock. Follow the label exactly, and never mix your own product or use anything that is meant for another animal.

Ask the vet to line the treatment up with your poultry vaccination schedule, so that the two do not clash. Treat the whole flock, not only the birds that show signs. Mites spread quickly among birds in the same house, and a bird that looks healthy can still carry the mites and reinfect the others. The vet will also say how long to wait after treatment before eggs or meat can be sold, and that withdrawal period is not optional.

Injured birds need separate care. A wound from pecking can become infected if it is left open, and the vet may recommend cleaning and a suitable wound treatment. Keep injured birds apart from the flock until they recover, so that other birds do not peck at them.

Cleaning the house and dealing with the harmattan dust

A mite problem needs a clean house as well as a treated flock. Remove litter and loose bedding from the nests and the floor under the perches, and clean the perches, nest boxes and feeders with water and detergent. Let them dry fully before the birds return. Mites and their eggs hide in the seams and in the litter, so a clean house is part of the treatment, not an extra.

The harmattan season brings dry, dusty air that irritates the skin and dries the feathers. Dust baths are natural behaviour for hens, and they help birds keep their feathers and skin clean. Give the flock a dry, fine-textured area of soil or sand where they can bathe, and keep the ground near the house clean and free of droppings. In the rainy season, damp litter and wet feathers cause other problems, so keep the floor dry.

Replace old or heavily soiled litter after treatment rather than mixing it back in. Keep the feeders and drinkers clean too, because contaminated feed and water can carry dirt and debris that irritate the skin.

Feed and care while the feathers grow back

Feathers are made largely of protein, so a bird with bare patches needs a diet that supports new growth. Check the feed label for the crude protein level and the age stage it is designed for. A layer ration suits laying hens, and a grower ration suits young birds. If you are unsure whether the feed is right, the poultry feed calculator for Ghana helps you check the amount and the mix, and a vet or feed supplier can check the composition.

Keep the birds calm while they heal. Reduce crowding, provide perches at different heights, and make sure feed and water are easy to reach. Shade in the hot months and good air movement at night help reduce stress and feather damage. A calm flock grows feathers faster than a stressed one.

Regrowth takes time. Pin feathers usually appear first, and the new feathers fill in over several weeks. If the bare patches are not filling in after the vet's treatment and a proper diet, go back to the vet, because the cause may be different from what you first thought.

Telling recovery from a flock that is getting worse

Keep a short record from the first day you notice the problem. Write the date, the number of birds with bare patches, the areas affected, whether the skin looks healthy or scabby, and any egg count changes. Repeat the check each week on the same birds, so that you can see whether the patches are shrinking or spreading.

A flock that is recovering shows fewer itchy birds each week, scabs that lift and skin that looks cleaner, and new pin feathers in the bare areas. A flock that is getting worse shows more birds scratching, a spread to new areas, deeper wounds and a steady fall in egg numbers. If the second pattern appears after treatment, call the vet again and ask whether the diagnosis or the treatment needs to change.

Keep the records with your other health records. The blog has more articles on flock health, and our frequently asked questions cover common questions about chicks and delivery. For the wider plan of the flock, including when to review it, speak to your vet.

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