If it killed a 65 lb dog, it very well could have killed a human, child or not. The "voltage dissipation" is just a canard; voltage is dissipated by driving a current through a resistance, and one flesh is pretty much as good a resistor as another. All you need is 5 milliamps in the right place (across the heart), that's enough to cause fibrillation to set in, and pretty much any flesh and blood can be a goner.
Actually, there are some mistakes here that need to be addressed.
First of all, assuming we're talking about alternating current (AC), 5 milli-Amps is
not enough current passing through the heart to cause fibrillation (heart attack). I commonly shock myself with this much current in my physics classes all the time in demonstrations, and I have yet to suffer any ill effects to my heart. In order to get fibrillation, you need on the order of 60-70 milli-Amps of current passing through the heart muscle. 5 milli-Amps is usually only enough to cause pain & discomfort.
Second, all flesh is not the same in terms of electrical resistance. Again, I perform demonstrations in my classes that clearly show the difference between being connected to a voltage source when the skin is dry (high resistance, low current) versus wet (low resistance, high current). This is why you're told never to mess with electrical equipment when you're in the shower or bathtub. Depending upon the circumstances, the difference in resistance (and therefore current) can be as much as 10 or 20x.
Third, there is a physiological point to be made. Dogs walk on all fours, while humans do not. This is important because when a current passes through a dog's body, since the front legs are on the ground, a large amount of this current will naturally pass through the dog's heart. Whereas with a human the legs come nowhere close to the heart, so the amount of current passing through a human heart is naturally less than for the dog. A similar phenomenon is observed with cattle dying during lightning storms for this same reason.
