The message
from "The Medway Handyman" contains
these words:

This is a very important issue, much more so because of the
horses. Tiny leakage currents which humans can barely feel
are fatal to most livestock including horses, so this has
to be got right.

Really? I didn't know that. What about electric fences for example?

I would have guessed that horses & cattle could have taken larger shocks
than humans because of thier greater mass. How does that work?

The problem comes from the greater wheelbase on a horse. What may be a
trivial potential gradient for a biped can knock off a quadruped quite
easily. This is why lightning rod terminals are buried a foot or so down
- keeps the surface potential gradient down.

--
Skipweasel
Pay no attention to that man behind the curtain.