It isn't hard to keep weight on old horses unless it hasa significant MEDICAL CONDITION that causes weight loss/inability to gain. All it takes is the right feed regimen and good basic senior care. People are commenting that there was food accessible. If the horses' teeth aren't cared for or the food is not easy for an old horse to chew and digest, all the food in the world won't get them to a healthy weight. It only takes a few things to get their weight up. First, have a dentist float their teeth at least twice a year. Horses must chew a huge amount of hay, grass, etc. every day, so old horses are highly prone to developing sharp edges and poor chewing surfaces. If they have reached the point where they're losing teeth or need unhealthy teeth removed periodically, have the dentist do a check-up more frequently. Second, feed a diet that they can easily chew and digest. Hay cubes, especially when soaked, are much easier to chew than hay, so the horse gets more nutrition from them. Since hay is harder to chew, it presents a much higher risk of choke than cubes. For grain, use a senior feed, soaked if necessary. Senior feeds are easy to digest and pack a lot of nutrition into a small volume of feed, so they are great for horses that have bad teeth. Regular deworming with a rotation that will cover all common parasites is essential. An old horse can't afford to lose calories to internal thiefs. \r
It is smart to have your vet help you design your senior's diet, but it's especially important if the methods above fail. Your horse may need a suppliment or weight building type of feed added. \r
I knew a 34 year old ""hard keeper"" TB with less than 10 teeth. On a diet with EVERYTHING soaked to mush, he was alive and kicking. He worked lightly every day and jumped little jumps a few days a week. He still jumped enthusiastically. His hips were a teeny bit prominent and a few ribs were very mildly visible when he moved just right. It's not hard if you truly care. \r
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Pros: He's in legal trouble
Cons: He is making money off of causing animals to suffer
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