There is a true saying "no foot, no horse". 

The farrier is the most important person along with your vet you can have when you own any equine

The donkeys are encouraged to stand and watch and be part of the trimming sessions, it teaches them there is nothing to be afraid of and joy oh joys they get treats!! Treats are to the donkeys the best things in life

Apart from neglect the biggest problem and what causes the most damage is the DIY brigade (do it yourself) it should be made law that anyone trimming their own equine's feet will be prosecuted (unless qualified). These people sometimes destroys donkeys feet, they cut them so short it becomes cruelty        

Below are photos of the Little long ears reactions to the farrier