You love horses. You even have one at home. In Thailand you're away from home and low and behold the beach ponies are out...wow for some tiny amount of local currency you can go for a lovely ride along the scenic beach!
Stop. Vacation beach ponies are not like your horse at home.
I'm sitting on Hua Hin beach in Thailand. Beach ponies complete with full tackle are up and down this beach for HOURS. I haven't seen a saddle come off nor a drink of water.
What I see is kids riding horses with no experience. I see adults far too heavy on tiny ponies.
These are beasts of burden in the true sense of the word. As a tourist you need to say NO. These people make thousands of baht a day. They are not poor locals. They are exploiting animals for the sake of tourism.
Hua Hin Is a beautiful city. Appreciate it on foot. Grab a deck chair and enjoy the scenery. Take a sunny walk along the beach. Give your money to a local charity or NGO. Visit the local schools to meet the community.
Give the ponies a rest. Help support the end of animals in tourism.