What are the parasites of the hen? What treatment?

The viruses that threaten the hens in our backyards are numerous and cause diseases such as Marek’s disease, avian influenza, infectious bursal disease or Newcastle disease. But parasites are not left out and are also the cause of many diseases. It is important to know them and to associate them with the most appropriate treatment.

Warning signs to look out for

The decrease in a hen’s activity or appetite is a signal that should never be overlooked. Likewise, the drop in laying, outside of normal seasonal fluctuations or in line with the aging of the hen, should be taken into consideration and should lead you to carefully monitor your animal, and perhaps consult a veterinarian.

A change appearance of droppings, the color of the crest, feathers or skin, a hen that scratches itself more than usual, hens that bite each other … By living with your hens, observing them and taking care, you have come to know them and you are the best person to know if something is wrong.

An inspection of the chicken coop can complete your diagnosis as some parasites can be visible to the naked eye.


This disease is caused by a very contagious parasite, theEimeria, which spreads in the hen’s intestine and is likely to cause visible bleeding in the stool. However, a hen can have coccidiosis without showing this type of symptom. There are 7 variations of this devastating parasite.

The oocysts, eggs which are the agents of transmission of the parasite, are extremely resistant, being able to survive for years outside the body of a hen. In farms, they are generally present and can even be transported from one farm to another by air, or under shoes. But the disease only develops if the area is not regularly disinfected and the parasite population is very large, or the chicks are too weak.

One of the most common cause of death in chickens, it constitutes a real scourge for poultry farms. There are many anti-coccidiosis products used both preventively and curatively, but they generate very significant additional costs for industrial breeding. The annual damage to this environment is estimated at 2 billion euros.

Intestinal worms

Intestinal worms are also one of the most common causes of death in hens. There are several kinds (roundworms, tapeworms, capillaries, syngamoses), causing more or less significant disorders: diarrhea, swollen and limp crop, loss of appetite and depression are the most common symptoms. Hens can infect themselves through their droppings.

There is no treatment because the hen declines quickly and dies. Prevention is the best way to protect your chickens: deworming your pets’ regularity is vital.

Chicken lice and fleas

Lice and fleas do not live on chickens all the time. If you provide the hens with a bin filled with a mixture of sand, soil and ash, they will normally do whatever it takes to get rid of it, that is, they will regularly roll around in the substrate.

Apart from the signals listed at the beginning of the article, a loss of feathers in the neck area, bite marks or a hen that itches frequently are signals that may indicate the presence of lice and fleas.

If the diagnosis is confirmed, disinfect the barn and apply a natural pest repellant such as pyrethrum powder.

Red lice

These red mites are mites and are far more dangerous than the lice we just mentioned. These animals suck the blood of the hen (like all the parasites that we talk about next). You only have a few days to react, otherwise the hen dies.

Only impeccable hygiene will protect your hens. The diatomaceous earth is very effective in eradicating the presence of these very tough lice.

Cnemidocoptes Laevis

This mite causes plumant scabies, another very contagious disease. Its presence is difficult to identify, since the manifestation of the disease does not differ much from the normal behavior of the hen: the hen loses its feathers during the molting period and scratches itself.

The treatment is the same as for scabies on the paws (see below).

Cnemidocoptes Mutans

This other hen mite causes symptoms localized on the legs, hence the name of the associated disease: paw scabies. The hen is limp, and growths with heaving scales, yellowish scabs, deformation of the fingers and / or enlargement of the legs are the manifestations that you will easily recognize.

Treatment involves applying ready-to-use cade oil to affected areas every 7-10 days until symptoms resolve.

How to limit parasites in the henhouse?

It is essential to react quickly by isolating any animal with suspicious behavior: it is the health of the entire henhouse that depends on it because any hen affected by parasites will contaminate the others, more or less quickly.

Following a few other rules will help protect your hens.

Thehygiene is of course essential. The hen house should be cleaned regularly, paying particular attention to the food and water containers which must be free from mold and algae. The hen house must have the minimum number of open joints and places of the same type, which are generally inaccessible for cleaning and are favorable places for the development of larvae which will re-trigger endless cycles of reinfestation.

Young individuals should be kept away from adults to allow them time to develop their immunity. Likewise, it is best to isolate newly acquired hens for at least two weeks.

The density of hens per square meter should not be too high, as overpopulation favors the transmission of parasites.

Ideally, the hens’ roaming area should be inaccessible to wild birds such as sparrows and starlings. It is also advisable to install rat traps.