Neurologic Behavior Signs in Sheep: Circling, Head Pressing, and Confusion

Neurologic behavior signs describe changes in movement, awareness, posture, or responses that suggest the brain, brainstem, or spinal cord may be affected. In sheep, circling often raises concern for listeriosis, sometimes called "circling disease," because affected animals may circle toward the damaged side of the brainstem. Head pressing is more often linked with forebrain disease, including polioencephalomalacia, lead toxicity, and some toxic or metabolic problems.

Your vet will also look for clues that help separate one cause from another. For example, unilateral facial droop, drooling, a dropped ear, or reduced eyelid function can support listeriosis. Blindness with a normal pupillary light reflex can fit cortical blindness seen with polioencephalomalacia. A history of access to batteries, old paint, machinery waste, or contaminated materials can increase concern for lead exposure.

Listeriosis is a bacterial infection caused by Listeria monocytogenes. In sheep, it is strongly associated with brainstem inflammation and may be linked to poor-quality or poorly fermented silage. Merck notes that affected ruminants can become depressed, disoriented, lean into corners, and circle, often with facial paralysis, salivation, and trouble chewing or swallowing.

Polioencephalomalacia, often shortened to PEM, is a syndrome of brain injury seen in ruminants. Sheep may first separate from the flock and stop eating, then develop cortical blindness, dorsomedial strabismus, stargazing, and head pressing. Some cases improve with early care, but delayed treatment can lead to recumbency, seizures, coma, or lasting blindness.

Other differentials include lead poisoning, enterotoxemia, brain abscesses, coenurosis, pregnancy toxemia in late-gestation ewes, rabies where relevant, and chronic neurologic disease such as scrapie. Scrapie is progressive and fatal, usually affecting adult sheep between about 2 and 5 years of age, and can cause behavior change, ataxia, tremors, reduced menace response, and weight loss.

See your vet immediately if a sheep is circling continuously, pressing its head into walls or feeders, appears blind, has a head tilt, drools, cannot swallow, is down, has seizures, or is separating from the flock with obvious confusion. These signs can progress fast, and some causes also create safety concerns for the animal and handlers.

While waiting for veterinary help, move the sheep to a quiet pen with good footing, shade, water access if it can swallow safely, and protection from getting trapped in corners or against fencing. Do not force-feed or drench a sheep with swallowing problems, because aspiration is a real risk. If toxins are possible, remove access to suspect feed, silage, paint chips, batteries, ash, or scrap materials and tell your vet exactly what the sheep may have contacted.

Diagnosis usually starts with a full physical and neurologic exam, temperature, pregnancy status when relevant, and a careful feed and environment history. Your vet may look for cranial nerve deficits, menace response changes, facial asymmetry, blindness, dehydration, rumen function changes, and signs of toxicosis or metabolic disease.

Depending on the case, testing may include bloodwork, ketone testing in late-gestation ewes, cerebrospinal fluid analysis, toxicology, and sometimes postmortem examination if a sheep dies. In field settings, your vet may also use response to treatment as part of the clinical picture, especially when PEM is suspected and thiamine is started quickly. Necropsy remains important for confirming some causes, including scrapie and certain brain lesions.

There is no single treatment for neurologic behavior signs because the best plan depends on the underlying problem. Listeriosis may be treated with early, aggressive antimicrobials and supportive care. PEM often prompts urgent thiamine therapy and correction of diet or sulfur-related risk factors. Toxicities require removing the source and targeted supportive care. Some structural brain diseases have a guarded outlook even with treatment.

The most helpful approach is to talk through options with your vet based on the sheep's age, pregnancy status, severity of signs, flock role, and your goals. In some cases, conservative monitoring is reasonable for a mildly abnormal sheep while diagnostics are limited. In others, same-day treatment or humane euthanasia may be the kindest option.

For 2025-2026 U.S. farm-animal care, a farm-call exam for a sheep with neurologic signs often falls around $150-$350, depending on region, travel, and emergency timing. Basic same-day treatment and supportive care may bring the total into the $250-$700 range. If your vet adds injectable medications, bloodwork, pregnancy-related testing, or repeated visits, costs commonly rise to about $500-$1,200.

More advanced care, referral hospitalization, imaging, intensive nursing, or extensive toxicology can move the cost range to roughly $1,500-$4,000 or more. Exact costs vary widely by geography, whether care is on-farm or in-hospital, and whether multiple sheep are affected.