When electrical stunning is carried out effectively, the result is essentially the same as an epileptic seizure in man, known as a grand mal epileptic fit, during which the brain is severely stimulated, the body exhibits tonic/clonic activity, and there is complete loss of consciousness. During the first (tonic) phase, when current flows through the brain, the animal collapses and stops breathing, with the front legs extended rigidly and the hind legs flexed into the body. The second (clonic) phase sees the animal relax and start involuntary kicking of both the fore and hind legs. As the clonic activity subsides, the animal moves into the third (recovery or exhaustion) phase.
It is recognised that while an animal is in the first two phases it is unconscious and, therefore, insensible to pain. However, the onset of the third phase is an indication that the animal is beginning to recover and may be able to experience pain. The first sign that an animal is recovering from the effect of the stun is a return to normal rhythmic breathing. Rhythmic breathing can be determined by watching for the rise and fall of the chest, with evenly spaced breaths. This should not be confused with random gasping (agonal breathing), a result of spasmodic muscle contractions, which can occur when the brain is dying. During these random contractions, air can also be forced from the lungs, causing the animal to make involuntary noises.
Phase |
Physical symptoms of an epileptic seizure |
Tonic |
Animal collapses and becomes rigid |
Clonic |
Gradual relaxation of muscles |
Recovery |
Resumption of normal rhythmic breathing |
Next: Electrocution
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