Am actually not sure about horses in Kenya. It is a tricky thing to buy since most of the horses in Kenya are found on ranches and large farms. They are therfore in the hands of very few people in Kenya.
I would advise you to look for more information when you get in Kenya. It may be helpful to ask in the local ranch owners organisations or post your interest in the social clubs near these residences I only have afew places in mind where one can post such a request:
at the Sarit center, airobi Club,Tigoni,Sigona golf Club.
I hope that this is of help to you.
where Africa comes to you..
