What is this shoe used for?

[Welly]

Hi there is a very sad article on the front page of H&H title "25-year-old showjumping groom dies" my sympathy for all concerned.
But could any one tell me what the name and use is of the shoe on the horse jumping in the picture?

 

[dalidaydream]

I think it's just both hooves together with normal shoes and studs (and not very healthy looking hooves)

 

[Welly]

Think I should go to specs savers.!