Lovely vintage book by Pamela Macgregor Morris
Still has its original dust cover
Illustrated by Lionel Edwards
Topper is a Welsh pony, typical of his breed in his looks, courage and kindly disposition. When Mr Tooley has to sell his London riding school, the pony is sent to the country, where he is bought for Beverly and Peter Sandford. He has the happiest of homes, and begins proving himself to be a first rate little hunter, he becomes well known as a showjumping at the local gymkhanas.
When Beverly and Peter are sent to America, however, and Topper has to be sold, he falls on bad days. He passes through several hands, among whom are two overindulgent children, who beat him and sicken him of jumping. At last, he winds up pulling a cart for a black marketeer.
The Sandford children, on their return from America, resolve to trace him and get him back again, but, as you will see, they have several adventures before they achieve their purpose.