Horses are herd animals and need to be with other horses.
My parents started me off when one horse, and they couldn't fathom why I wanted more. But, I now have 4 and they realize how important it was to have more than one horse.
First horse Dream had a baby, so that brought my number up. Dream was an amazing western pleasure horse, but I needed a new drill horse. She wasn't fast enough, and had issues with kicking at other horses. Mango had passed away at the early age of 21, and I couldn't quit drill and Sassy was only 1..
So, along came Rosie. Rosie is 21 now also, but she does Foundation(ranch type) shows with me. She can still do drill, but I had to quit this year for college:'(
Rosie helped me win Dusty in a contest. Dusty is going to be my show horse through college and beyond, either reining, cutting or sorting (currently in training).
Rosie is slowing down a tad but still kicks butt at shows. She still has many years of service available, but when the time comes for her to retire, Dusty will be there as my Foundy show horse. I could never sell Rosie as I have personal morals against selling senior horses, and she has been my partner for the past 4? years. She'll be with me till her last day
Sassy is an illegitimate child, unknown to the REAL owners of the stud we bred to, so there is never any chance of getting papers out of her. I refuse to sell her, because I know it wouldn't take long before somebody would give her a first class ticket to the kill pens. She has an attitude a mile wide and a personality to match her name. Given, yes, she is an amazing horse, but she has a serious "I'm the best, your so stupid, I'll do whatever I want" problem XD
There are many reasons for having more than 1 horse. I don't ride Dream very much any more, and it breaks my heart to have grown from her, but she needs a new home where she will be used and shown.:'(