Sheep Hot Spots or Moist Skin Lesions: Causes & What to Do

Moist, inflamed skin in sheep is usually a sign, not a diagnosis. One common cause is dermatophilosis (sometimes called rain rot or lumpy wool), a bacterial skin infection that tends to flare when skin stays wet and the normal skin barrier is damaged. In sheep, prolonged rain, humidity, and irritation from external parasites can all set the stage. Lesions may start as matted wool or hair, then become crusty, scabby, or moist underneath.

Another important cause is fly strike. Blow flies are strongly attracted to moist wounds, soiled wool, and draining skin lesions. Once eggs hatch, maggots can spread quickly and damage skin fast. Fly strike may begin around the breech, wounds, feet, prepuce, or any damp area of fleece, especially during warm, humid weather.

Lesions near the feet can come from interdigital dermatitis or skin damage associated with footrot. Merck notes that interdigital skin may look red, swollen, hairless, and moist, particularly in wet, muddy conditions. Sheep may also develop skin irritation from lice, keds, rubbing, minor trauma, or secondary infection after another skin problem starts.

Your vet may also consider orf and other less common causes. Orf usually causes crusting and proliferative lesions around the lips, but it can also affect the feet or teats and can be passed to people. Because several conditions can look similar early on, a hands-on exam matters before treatment decisions are made.

See your vet the same day if the lesion is foul-smelling, oozing heavily, crawling with maggots, very painful, rapidly enlarging, or causing lameness, weakness, fever, or poor appetite. These signs raise concern for fly strike, deeper infection, or significant tissue damage. Lambs, thin sheep, and animals with multiple lesions should also be seen sooner rather than later.

A small, superficial moist patch may be reasonable to monitor briefly while you arrange care, especially if your sheep is bright, eating, walking normally, and the area is not worsening. Even then, close observation is important because skin lesions in wool-bearing animals can hide more damage than you can see from the surface.

Call your vet promptly if the lesion is near the feet, udder, eyes, mouth, or genitals, or if several sheep in the flock are affected. Those patterns can suggest contagious disease, management-related moisture problems, or a parasite issue that needs flock-level planning.

Use gloves when handling suspicious crusting lesions, especially around the mouth or teats, because orf is zoonotic. If you are not sure whether you are dealing with a simple skin irritation or something more serious, it is safest to involve your vet early.

Your vet will start with a physical exam and a close look at the lesion location, odor, moisture, crusting, wool condition, and whether flies or maggots are present. They will also ask about recent rain, mud, shearing, lambing, foot problems, parasite control, and whether other sheep are affected. That history helps narrow down whether the problem is more likely bacterial, parasitic, traumatic, or contagious.

Depending on the case, your vet may clip or part the wool to fully expose the skin, clean the area, and remove debris or maggots. They may check the feet for interdigital dermatitis or footrot, and they may recommend skin sampling, cytology, or lab testing if the diagnosis is unclear or the lesion is not responding as expected.

Treatment often focuses on the underlying cause plus local wound care. That can include topical antiseptic cleansing, fly control, pain relief, and in some cases prescription antimicrobials or other medications chosen by your vet. If the lesion is severe, your vet may debride damaged tissue and discuss isolation or handling precautions if a contagious condition such as orf is on the list.

For flock situations, your vet may also review housing, drainage, bedding, shearing timing, crutching, parasite control, and ways to reduce moisture and fecal or urine contamination. That broader plan is often what prevents repeat cases.

If your sheep has a moist skin lesion, keep the animal in a clean, dry area and reduce exposure to mud, manure, and rain while you contact your vet. Check the lesion at least daily. If wool is heavily soiled around the area, your vet may advise clipping or shearing nearby wool so the skin can dry and be monitored more accurately. Do not dig into crusts or aggressively scrub raw tissue.

Protect the area from flies. Fly strike can develop quickly in damp, irritated skin, so this step matters. Follow your vet's guidance on wound cleansing and any approved topical products. Avoid using random household antiseptics, caustic sprays, or leftover medications, because some products can delay healing or make diagnosis harder.

Handle suspicious crusting lesions with gloves, especially if they are around the mouth, teats, or feet, because orf can infect people through broken skin. Wash hands and equipment well after handling. If more than one sheep is affected, note which animals have lesions and whether they share the same pasture, bedding, or recent weather exposure.

Call your vet sooner if the patch gets larger, smells bad, starts draining more, attracts flies, causes lameness, or your sheep stops eating normally. Early treatment is usually easier, less stressful, and less costly than waiting for a small wet lesion to become a major wound.