OP, I am sorry that the purchaser of your horse did not honor a verbal agreement. I can understand the emotional aspect of this deal, in particular.
As an owner, I try to respect the name a breeder has given a horse; however, I have changed some of my horses’ names if it suited my needs and not for any nefarious reason. First, I like to have a name that is somewhat unique. I do not want my horse to be confused with 14 other horse’s showing in the same division in the same general region in the same time period. Secondly, I would prefer to have a name that is not offensive, just awful, or doesn’t fit with the discipline I plan on riding with it. If I can give homage to the breeder or the horse’s breeding, I will try to do so, even if I change the horse’s name.
Here are some examples of my thoughts in changing a name.
My first pony’s name had a famous farm name as a prefix and part of its name referenced its sire. I liked the name, it was unique. It stayed.
The second was an OTTB with a gawd-awful name that had no reference to her breeding or breeder. She wasn’t breeding material, she did not show much, and we kept her until her dying day. Name changed.
Third was an import with a unique name according to the USEF <at the time>. The name meant something to the registry and it wasn’t awful. It stayed although it did end up showing against a horse of the same name for a bit - grr!. Although there are still only a handful with the name, according to USEF.
Fourth had a name in which there are about a 100 horses registered with USEF with that very same name within the same age cohort. Too many to sort through to see whether they could be in the same area / divisions. Name was changed; however, we keep the same 1st letter of the sire’s name, consistent with the registry.
As we are not trying to hide anything, all of these horses were registered with USEF and, their breed, breeder, sire, dam, registry (registered name), etc. are all included with their registered information.
While I appreciate that it is hard to name a horse and that, in many cases, as much effort goes into naming a horse as it does creating a horse, sometimes the names just don’t send the right message. For example, if I have a lovely derby horse that happens to be a quarter horse with the name Sheeza Lotta Horse or a lovely TB A/O Hunter with the name Speeddemonfromhe((. It is not that I am not proud of my horse and its breeding; I just don’t think they fit the hunter naming conventions or help create the image I would be looking for for that horse. Also, if your stallion’s name is Bell Amore and you sell me a lovely mare named Bella, even with a farm prefix / suffix I am also probably going to change it because it is just too common of a name.
My goal in naming a horse is to find a name that will be memorable, in a good way.