Bovine Encephalitis and Nervous System Disorders: Welfare

Key Facts

• Polioencephalomalacia (PEM) is the most common bovine nervous disease, caused by thiamine deficiency
• Listeriosis (circling disease) causes distinctive head tilt, facial nerve palsy and circling behavior
• Thromboembolic meningoencephalitis (TEME) caused by Histophilus somni is a feedlot emergency
• Early neurological signs include separation, dullness, apparent blindness and lack of menace response
• Prompt thiamine supplementation for PEM cases results in dramatic recovery if treated within 24 hours

Welfare Considerations

Neurological disease in cattle causes significant welfare suffering. Affected animals cannot navigate their environment, find water or feed, or escape social dominance. They are vulnerable to trampling and drowning in water troughs. Recumbent animals require careful nursing: padding, turning every 4 hours, and hand-feeding. The welfare imperative is early recognition and prompt treatment — PEM in particular responds spectacularly to IV thiamine if caught early. Animals that do not respond to treatment within 24-48 hours face a poor prognosis and humane euthanasia should be considered.

What You Can Do

• Train farm staff to recognize early neurological signs: star-gazing, apparent blindness, circling
• Keep IV thiamine accessible on farm for immediate PEM treatment pending vet arrival
• Isolate and nurse recumbent neurological animals with appropriate bedding and turning protocol
• Ensure water trough design prevents drowning of disoriented animals
• Contact your vet immediately for any animal showing acute neurological signs