FieldDxStray voltage injuryClinical signs, differential diagnosis, treatment and prevention in cattle, sheep and horses.
Overview
Low-level electrical current in animal housing that mainly affects dairy cows and swine, often causing avoidance behaviour. Current from a farm's grounded-neutral electrical system passes through an animal that touches two points at once.
Clinical signs
- Mild flinching or other signs of perceiving current, with little change in routine.
- Avoidance of affected areas such as water troughs.
- Fewer drinks per day, each taking longer.
- Reluctance to move into or out of buildings.
- Raised stress hormones in some cows at high exposures.
Predisposing factors
- Loose electrical connections and ground faults.
- Undersized wiring, or wiring damaged by animals.
- Moisture and corrosion in the electrical system.
- Unbalanced electrical loads and accidents.
Treatment
No direct treatment for the animal; management is correcting the electrical fault (grounding, wiring) causing the stray current, since low-level exposure alone is not established as a cause of major production or health problems.
Prevention
1. Keep the farm electrical system to electrical code. 2. Install equipotential planes where animals make contact. 3. Have an electrician or power supplier inspect and test periodically, especially after electrical changes. 4. Repair damaged electrical equipment promptly. 5.
Source
MSD Veterinary Manual — Stray Voltage in Animal Housing (accessed 2026-08-12)
MSD Veterinary Manual — Stray Voltage in Animal Housing (accessed 2026-10-29)
Condensed and attributed, never reproduced whole. Open the full entry in the app.