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Chorioptic mange (paw scabies)
Chorioptic mange is scabies of the legs. Its mite lives on the surface of the skin, without digging, and remains confined to the lower body: pasterns, fetlocks, under the hocks, inner side of the thighs, and – this is the crucial point – th...
What is it?
Chorioptic mange is scabies of the legs. Its mite lives on the surface of the skin, without digging, and remains confined to the lower body: pasterns, fetlocks, under the hocks, inner side of the thighs, and – this is the crucial point – the scrotum of the ram.
This is what separates it from other sheep scabies, and you need to know this so as not to mistake the disease. Psoroptic mange invades the body under the wool and destroys the fleece; sarcoptic mange settles on the head and areas with little wool; Chorioptic mange practically never grows and is limited to the extremities. The general sheet on sheep scabies presents this set; this details the shape of the limbs.
Less spectacular than scabies, it is often tolerated or ignored for months. This is a mistake: in the ram, inflammation of the scrotum raises the temperature of the testicles, and this is enough to degrade fertility at the precise moment when we count on it.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
Scratching and trampling: the animal stamps its feet, bites the bottom of its legs, rubs its limbs against barriers and walls, licks its pasterns.
Dry, grayish, adherent crusts on the pasterns and the tops of the hooves, which slowly extend upwards from the limb.
Loss of hair in patches on the lower legs, with skin that turns red, then thickened, wrinkled and dark where the lesions have lasted for a long time.
In rams: skin of the scrotum red, crusty, thickened, sometimes oozing. This is the lesion to systematically look for before the wrestling season, and it goes completely unnoticed if the animal is not turned over.
Lameness or stiff gait in animals with very damaged pasterns; some refuse to walk for long.
In sheep, possible damage to the underside of the udder and the inner side of the thighs, which interferes with breastfeeding.
Agitation in the sheepfold, animals getting up and lying down, eating in spurts.
The lesions worsen in winter, on damp litter, and often regress on their own on pasture without the parasite disappearing.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
The mite lives on the surface of the skin and feeds on skin debris, without digging a gallery.
It has a marked preference for the lower areas of the body, cooler and more humid, which explains its location on the limbs and the scrotum.
As with other scabies, the suffering comes from the skin's reaction to the parasite's secretions: inflammation, scabs, progressive thickening.
On the ram's scrotum, this local inflammation causes the temperature of the testicles to rise. Sperm production is very sensitive to heat: this is the mechanism by which a simple skin disease becomes a reproductive problem.
Outside of the animal, the mite survives for a time in damp litter and on equipment, which maintains the infestation in buildings.
Accommodation in buildings in winter, damp litter and rarely replaced, high density, poor ventilation.
Rams purchased or loaned without scrotal examination: this is the most classic entry point.
Mixture of sheep and goats in the same premises.
Animals in poor condition, deficient or already carrying other parasites.
Pre-existing limb lesions, damaged feet, chronic lameness.
Lack of control of rams before the breeding season.
Partial treatments, limited to visibly affected animals.
Transmission
By direct contact between animals, particularly in sheepfolds in winter, between animals lying side by side.
Through damp litter, cubicles, sleeping areas and equipment, where the mite persists for a certain period of time.
By loaned rams and purchased animals, often discreet carriers of a scrotal lesion that no one looked at.
Between sheep and goats sharing the same buildings.
This scabies does not settle permanently on humans.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
The examination must be targeted, and this is where many cases go wrong: you have to look at the bottom of the legs and, in rams, turn the animal over to examine the scrotum. Chorioptic mange is not seen by looking at a standing flock.
The veterinarian scrapes the skin at the edge of the scabs and identifies the mite under a microscope. This examination is essential, because scabs on the bottom of the legs can also come from other causes: dermatophilosis of the limbs, foot rot and hoof conditions, injuries.
He examines several animals in the lot, including those that are not scratching.
Before the fighting season, a check of the rams, including examination of the scrotum and general condition, is the best possible investment: it avoids discovering a fertility problem once the season is over.
In sheep, the veterinarian also checks the underside of the udder, an area often affected and rarely inspected.
Treatment
External antiparasitics suitable for sheep, applied to the skin, as a spray or in a bath, are the basis of treatment. The choice of product is up to the veterinarian.
An important point: injectable antiparasitics, very effective on body scabies, give much less constant results on limb scabies, because the mite lives on the surface of the skin and feeds on debris, not blood or tissue fluid. Here again, getting the wrong scabies means getting the wrong treatment.
The product must reach the skin: you must clean the thick crusts and really treat the lower areas, often soiled with mud and manure, otherwise the treatment is useless.
The whole lot is treated at the same time, and the rams must never be forgotten - they are the ones who carry the heaviest lesions and who redistribute them.
A second pass is usually necessary; the veterinarian sets the course and the interval.
The building is part of the treatment: renewed litter, sanitized sleeping areas, improved ventilation. A damp shelter cancels the effect of any product.
No dose or rhythm is improvised, and we never use products intended for other species or homemade preparations on already damaged skin.
Withdrawal times for meat and milk vary depending on the product and should be requested from the veterinarian.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Examine the scrotum of any ram purchased or loaned, before introduction and before each wrestling season: this is the action that avoids the majority of problems.
Quarantine purchased animals and inspect the bottom of their limbs.
Maintain the litter: dry, renewed and well-mulched litter is the best prevention against this scabies.
Ensure ventilation and avoid overdensity in the sheepfold in winter.
Take advantage of work on the feet, trimming and clipping to systematically look at the bottom of the legs.
Treat the entire flock at the same time as soon as a case is confirmed, rather than leaving affected animals lying around.
Maintain good general condition of the herd and correct deficiencies.
Possible complications
Reduced fertility in the ram, sometimes for an entire season of struggle: empty ewes, delayed lambing, compromised countryside. It is the most expensive complication and most often discovered too late.
Permanent thickening of the skin of the pasterns, which remains hard, wrinkled and dark even after healing.
Persistent lameness and refusal to walk in the most affected animals.
Scraping wounds that become infected, abscesses, and entry point for other limb conditions.
Damage to the udder which interferes with suckling and penalizes the growth of the lambs.
Infestation which settles permanently in a damp building and returns every winter.
When to see a veterinarian
Animals stamp their feet, chew the bottom of their legs or rub their limbs against the barriers.
Gray crusts appear on the pasterns and run up the length of the limbs.
A ram's scrotal skin is red, crusty or thickened: have it examined before wrestling season.
A ram has been used and many ewes are coming back into heat: ask for a complete check, including the skin of the scrotum.
An animal limps or refuses to walk without visible hoof damage.
Scabs appear under the udder of a nursing ewe.
You have just introduced or borrowed a ram and itchy paws appear in the lot.
Prognosis
The skin prognosis is good when the diagnosis is confirmed, the entire flock is treated and the litter is sanitized; the scabs disappear and the hair grows back.
Skin that is very thickened by old lesions often retains a permanently altered appearance.
In rams, fertility generally returns after recovery, but it takes time: sperm production does not return to normal overnight. A ram treated too late remains unusable for the current season, which calls for control well before the fight.
Recurrences are common in damp buildings and when rams are not included in the treatment.
Frequently asked questions
How is it different from ordinary sheep scab?
By location, and therefore by treatment. This mange remains on the bottom of the legs and on the scrotum of the ram, while body mange invades the fleece on the sides and back, and head mange affects areas with little wool. Mites are not the same and do not respond to the same products: only scraping examined under a microscope can make a decision.
My ram has crusted scrotal skin, is this serious for reproduction?
Yes, it should be taken seriously. The inflammation heats the testicles, and sperm production does not cope well with the heat. A ram in this condition may impregnate far fewer ewes than expected. Have it examined before wrestling season, not after.
The injectables I use for scabies don't work here, why?
Because this mite lives on the surface of the skin and feeds on skin debris, without drawing blood: injectable products reach it much less well than those applied directly to the skin. This is an important difference between scabies, and one more reason to have the parasite identified.
The lesions disappear on pasture in the summer, is this cured?
Not necessarily. The signs diminish with the sun and drought, but the mite often remains present in small numbers and leaves as soon as you return to the sheepfold. This is why the disease seems to return every winter: it never left.
References
FAO — Organisation des Nations unies pour l'alimentation et l'agriculture
ANSES — Agence nationale de sécurité sanitaire (France)
Content reviewed by the TunisieVet editorial team · Updated 11 August 2026
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