Does your horse suffer from stomach ulcers?
Then you know how frustrating that can be. You pay for expensive vet visits and medication. A short time later, your horse is no longer in pain and seems to feel well again. He suddenly eats better, enjoys training again, and performs well at shows...
... until the medication is discontinued and excess gastric acid begins to form again, which attacks the stomach mucosa again.
And you're right back where you started: your horse pins his ears while being saddled, bucks after jumping, or seems to lose weight overnight.