Horse licking mud off other horse's fetlocks

[Petalpoos]

Just curious, but has anyone else seen this behaviour? One of my mares licks at the mud on my other mare's hind fetlocks and pasterns. Both horses have access to the field so the mud on the legs is the same as is available in the field (!). I have seen her doing this occasionally over the last 2 years, usually when they are standing by the gate in the late afternoon waiting for their tea. The licked horse does not seem to care at all. Maybe I just have a horse with a foot/mud fetish

 

[Antw23uk]

I witnessed this before with one of mine and he went on a balancer and had a salt lick added to his stable. I figured when you see wild animals going to rocks and muds to get the trace minerals they are lacking in their diet its the same thing? Thats how i saw it anyway, lol