Listeriosis in Cows: Circling Disease and Facial Nerve Signs in Cattle
- See your vet immediately if a cow is circling, leaning, has a head tilt, facial droop, drooling, or trouble chewing and swallowing.
- Listeriosis is a serious bacterial infection, usually linked to poor-quality or spoiled silage, that often affects the brainstem in cattle.
- One-sided facial and trigeminal nerve deficits are especially important clues. You may notice a dropped ear or eyelid, reduced facial sensation, salivation, or feed falling from the mouth.
- Early treatment matters. Cattle treated before they become down or severely neurologic have a better chance of survival than those treated late.
- Typical veterinary cost range in the US is about $250-$800 for farm-call exam and initial treatment in straightforward cases, $800-$2,500 for several days of on-farm care and medications, and $2,500-$6,000+ for referral-level hospitalization or intensive nursing.
What Is Listeriosis in Cows?
Listeriosis is an infection caused by the bacterium Listeria monocytogenes. In cattle, the best-known form is the neurologic form, often called circling disease, because affected animals may walk in circles, lean into objects, or seem disoriented. The infection commonly localizes in the brainstem, where it can damage cranial nerves and cause the one-sided facial signs that make this disease so recognizable.
Many cattle with listeriosis start with vague changes such as depression, reduced appetite, and separation from the herd. As the disease progresses, neurologic signs become more obvious. These can include head tilt, drooping ear or eyelid, drooling, feed packing in the cheek, and trouble swallowing. Merck Veterinary Manual notes that cranial nerves V, VII, and VIII are often involved, which helps explain the facial paralysis, loss of facial sensation, and vestibular signs seen in many cases.
This is an emergency because cattle can worsen quickly. Some become recumbent, develop severe depression, or die if treatment is delayed. Even when recovery is possible, the best outcomes usually happen when your vet starts treatment early and the cow is still standing and able to swallow safely.
Symptoms of Listeriosis in Cows
- Circling or leaning to one side
- Head tilt
- One-sided facial droop or ear droop
- Drooling or excessive salivation
- Feed falling from the mouth or difficulty chewing
- Trouble swallowing or repeated choking-like motions
- Depression, dullness, or isolation from the herd
- Ataxia, stumbling, or weakness
- Reduced blink, dropped eyelid, or absent menace response
- Recumbency or inability to rise
Early signs can be easy to miss, especially if only one side of the face is affected. A cow may look dull, stop eating well, or hold the head slightly tilted before the classic circling starts. As brainstem inflammation worsens, facial nerve and trigeminal nerve deficits may become clearer, with drooling, a dropped ear, reduced facial sensation, or feed collecting in the mouth.
See your vet immediately if you notice circling, head tilt, trouble swallowing, repeated drooling, or any cow that is becoming weak or going down. These signs can overlap with other serious neurologic diseases, including rabies, polioencephalomalacia, histophilosis, lead poisoning, and inner ear disease, so prompt veterinary evaluation is important for both animal health and herd safety.
What Causes Listeriosis in Cows?
Listeria monocytogenes is widespread in the environment and can be found in soil, water, feces, and decaying plant material. In cattle, outbreaks are classically associated with poorly fermented or spoiled silage, especially when the silage pH is not low enough to suppress bacterial growth. Feeding from visibly moldy, dirty, or air-exposed sections of a bunker, bag, or bale increases risk.
The bacterium is usually thought to enter through the mouth, especially when there are small abrasions in the oral tissues from coarse feed. From there, it can travel along cranial nerves to the brainstem, which helps explain why the neurologic form often causes asymmetric cranial nerve signs rather than generalized whole-body illness at first. Animal-to-animal spread can also occur by the fecal-oral route, but feed management is the most important practical risk factor in many cattle cases.
Listeriosis is not always limited to the neurologic form. Listeria can also cause abortion, septicemia, or eye infections, but circling disease is the form most pet parents and producers notice first in adult cattle. Risk tends to rise in colder months when silage feeding is heavier and spoiled pockets are more likely to be fed.
How Is Listeriosis in Cows Diagnosed?
Your vet usually starts with history and a focused neurologic exam. The combination of silage exposure, depression, circling, head tilt, and one-sided facial or trigeminal nerve deficits is highly suggestive. Merck Veterinary Manual specifically notes that unilateral facial and trigeminal paralysis in cattle can help distinguish listeriosis from several other neurologic conditions.
Diagnosis is often clinical in a live cow because confirming the organism can be difficult. Your vet may assess swallowing ability, facial sensation, ear and eyelid position, menace response, tongue tone, and whether the cow is bright or depressed. Depending on the case, they may also recommend bloodwork, cerebrospinal fluid testing, ketone testing to help separate ketosis, or additional herd and feed evaluation.
Definitive confirmation may require laboratory testing of tissues, especially after death. Necropsy and laboratory submission can be very helpful if more than one animal is affected or if the diagnosis is uncertain. This is also important because rabies must remain on the differential list for cattle with neurologic signs, and that changes handling and biosecurity decisions.
Treatment Options for Listeriosis in Cows
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Urgent farm-call exam by your vet
- Neurologic assessment and discussion of likely differentials
- Early injectable antimicrobial plan directed by your vet, commonly high-dose penicillin or oxytetracycline when appropriate
- Anti-inflammatory medication if your vet feels it is appropriate
- Immediate removal of suspect silage or spoiled feed
- Basic nursing care: easy access to water, palatable feed, shade or shelter, and close monitoring for swallowing ability and recumbency
Recommended Standard Treatment
- Repeat veterinary visits or structured on-farm treatment plan over several days
- Full-dose antimicrobial therapy for 1-2 weeks as directed by your vet
- Anti-inflammatory and pain-control support when appropriate
- Fluids or electrolyte support if dehydration is present
- More intensive nursing care, including assisted feeding decisions and eye protection if blink is reduced
- Evaluation of the ration and silage source, with recommendations for herd-level feed changes and monitoring of exposed cattle
Advanced / Critical Care
- Referral or hospital-level care when available and practical
- Intensive IV fluids, repeated neurologic monitoring, and advanced nursing support
- Management of recumbency complications such as pressure injury, dehydration, and aspiration risk
- Tube feeding or more advanced nutritional support only when your vet determines it can be done safely
- Expanded diagnostics to rule out other neurologic diseases and guide herd biosecurity decisions
- Necropsy and laboratory workup if prognosis becomes poor or if herd-level investigation is needed
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Listeriosis in Cows
Bring these questions to your vet appointment to get the most out of your visit.
- Do my cow's one-sided facial signs and circling fit listeriosis, or are other neurologic diseases still likely?
- Is this an emergency that should be treated on the farm today, or does this cow need referral-level care?
- Can my cow swallow safely, or is there a risk of aspiration if we offer feed and water normally?
- Which antimicrobial option makes the most sense here, and how long should treatment continue?
- What signs would mean the prognosis is getting worse, such as recumbency, loss of blink, or worsening depression?
- Should we pull and discard any silage or feed right away, and how should we inspect the rest of the stored feed?
- Do other cattle in the group need monitoring, treatment, or ration changes?
- Are there any handling or biosecurity precautions we should take while rabies and other neurologic diseases are still being considered?
How to Prevent Listeriosis in Cows
Prevention focuses first on feed quality. Good silage management matters more than any supplement or shortcut. Harvest at the right moisture, pack and seal well, limit oxygen exposure, and avoid feeding visibly spoiled, moldy, dirty, or poorly fermented sections. If a bunker face, bag opening, or bale edge looks questionable, ask your vet or nutrition team whether it should be discarded rather than fed.
Clean feed bunks, water sources, and storage areas regularly to reduce contamination with manure and decaying organic material. Try to minimize oral injury from coarse, stemmy, or contaminated feed, since damaged mouth tissues may make it easier for Listeria to invade. If you have one suspected case, remove the same feed source from pen mates or herd mates until your vet helps assess the risk.
There is no commonly used routine vaccine program for the typical neurologic form of listeriosis in cattle. That means practical prevention depends on forage management, prompt removal of spoiled silage, and early recognition of subtle neurologic signs. Fast action protects the affected cow and may also help prevent additional cases linked to the same feed source.