Why Do Sheep Pull or Chew Wool?

The most recognized cause is frustration of normal grazing behavior. Merck describes wool pulling as an abnormal sheep behavior seen when sheep are confined without enough opportunity to graze. It can resemble grazing behavior directed at flockmates instead of forage. Risk goes up when sheep are crowded, housed in barren areas, or fed diets that do not provide enough effective roughage.

Nutrition can also play a role. Sheep need consistent access to appropriate forage, salt, and a sheep-safe trace mineral program. Merck notes that low-quality forage can limit performance and that wool quality is affected by nutritional plane. Extension research also suggests ruminants may seek unusual materials when mineral balance is off. That does not mean every wool-chewing sheep has a deficiency, but it is a good reason to review the ration with your vet or a flock nutrition professional.

Skin irritation is another major category. Lice, sheep keds, and fly strike can cause pruritus, restlessness, rubbing, and biting at the fleece. In these cases, the wool damage may look like a behavior problem at first, but the real trigger is itch or pain.

Look beyond the chewing itself. Sheep with a management-driven behavior problem may spend time nibbling flockmates in pens, especially around feeders or during long periods without grazing. You may notice sparse wool on the shoulders, flanks, or rump of the sheep being targeted.

If parasites or skin disease are involved, there may also be rubbing on fences, scratching, dirty or ragged fleece, scabs, irritated skin, or visible wool loss. Sheep keds and lice are both associated with fleece damage, and heavy infestations can reduce thrift. Fly strike is more urgent and may come with foul odor, damp or discolored wool, distress, and rapid decline.

If nutrition is part of the problem, you may also see poor body condition, reduced growth, weak fleece, or changes in flock-wide wool quality. A ration review is especially important if the flock recently changed hay, pasture access, mineral source, or stocking density.

Your vet will usually start with flock history and a hands-on exam. Helpful details include when the behavior started, whether it is seasonal, what the sheep are eating, how much feeder space is available, and whether only one group is affected. Your vet may inspect the skin and fleece closely for lice, keds, irritation, or evidence of fly strike.

Depending on the case, your vet may recommend fecal testing, skin and fleece inspection, body condition scoring, and a review of the ration and mineral program. In some flocks, bloodwork or targeted mineral testing may be useful, especially if there are broader signs of poor thrift or suspected deficiency. Because sheep are sensitive to copper toxicity, do not switch to cattle or goat minerals without veterinary guidance.

This workup helps separate a behavior issue from a medical one. That matters, because treatment options are different if the main driver is boredom and low forage versus parasites, pain, or a ration problem.

Management often starts with the basics: increase access to good-quality forage, reduce crowding, improve feeder access, and give sheep more opportunity to express normal grazing behavior. For confined flocks, that may mean more hay availability, slower feeding systems, more bunk space, turnout time, or environmental changes that reduce idle time.

If your vet finds parasites or skin disease, treatment may include shearing or crutching affected areas, flock-appropriate parasite control, and changes to hygiene or housing. Fly strike needs prompt veterinary attention because affected sheep can worsen quickly.

When nutrition is a concern, your vet may recommend adjusting forage quality, balancing energy and protein, and using a sheep-specific mineral mix. The goal is not one universal fix. It is matching the plan to the cause, the flock setup, and your practical budget.

Call your vet soon if multiple sheep are affected, if there are bald patches or skin wounds, or if any sheep are losing weight or acting restless. Fast veterinary input is especially important if you see foul-smelling or wet wool, maggots, severe itching, pale gums, weakness, or sudden drop in appetite.

See your vet immediately if you suspect fly strike, severe anemia, or a toxic feed or mineral exposure. Sheep can deteriorate quickly when skin disease, parasites, or nutrition problems are advanced.

Even when the behavior seems mild, early changes in feeding space, forage access, and flock monitoring can prevent a small wool-chewing problem from becoming a larger welfare and fleece-quality issue.