Interesting because my experience is the opposite. Horses that I have had in natural
range pasture in Cuyama Valley Calif. certainly know the sound of a rattlesnake. (About
10 horses in the last 7 years) They jump away from the sound the minute they hear it.
They also give other snakes a wide berth if they see them. Horses I have never put out
on the range don't have this reaction. Just last week we had two horses out on a ride
here, one from Cuyama and the other a local. A rattlesnake rattled in the grass and the
Cuyama horse jumped away while the local horse couldn't care less.
I believe the range horses sniff around a snake in the grass and get struck at or bit
and learn to avoid them. Many times rattlers strike a bigger animal but do not inject.
And other snakes bite also.
Jim Mitchell
Bakersfield, Ca.