Injury or death of a pet due to high-voltage electrical currents may be the result of lightning, fallen transmission wires, faulty electrical circuits, or chewing on an electrical cord. Lightning strike is seasonal and tends to be geographically restricted. Investigation of possible electrocution should always proceed with caution because the electrification resulting from broken transmission wires, for example, may still be present.
Certain types of trees, especially hardwoods such as oaks and those that are tall and have spreading root systems just beneath the ground surface, tend to be struck by lightning more often than others. Electrification of such roots charges a wide surface area, particularly when the ground is already damp; passage of charged roots beneath a shallow pool of water causes it to become electrified. Fallen or sagging transmission wires also may electrify a pool of water, fence, or building, and an animal may also directly contact such wires.
Varying degrees of electric shock may occur. In most instances of lightning strike, death is instantaneous and the animal falls without a struggle. Occasionally, the animal becomes unconscious but may recover in a few minutes to several hours; residual nervous signs (including depression, paraplegia, and increased skin sensitivity to normally painless stimulus) may persist for days or weeks or be permanent. Death from electric shock usually results from cardiac or respiratory arrest.
Lightning strike and electrocution should be considered true emergencies in which your veterinarian should be contacted right away. Even if the effect of electrocution appears mild (as in a pet chewing on an electrical cord), signs of shock or other complications may occur later. Animals that survive may require supportive and symptomatic therapy.