16% protein is not too much, and certainly not too much at 1, maybe 2lb. And even if it’s just 2lb, that’s only 145gm protein and possibly not ENOUGH, especially if he’s not eating enough hay.
Horses don’t have an inherent need for high fat diets. It’s not how they evolved. Forages are naturally low in fat. SOME horses have a higher fat requirement. It’s a lot of good marketing that has people hooked on the notion that if a feed isn’t 10% fat, it’s not high enough.
OP - glad your vet is coming Friday. A good blood workup is in order, as are a thorough look at his teeth, including sedation to put on a speculum so that his molars can be properly assessed.
3lb beet pulp/alfa combination - how much of each? Beet pulp is very high volume per pound (assuming shreds, need to know if that’s pellets), and once soaked (which should be non-negotiable for this horse) is a huge volume. That’s not what this horse needs. He needs calorie-dense feedstuffs.
What is your feed, exactly? It’s not a ration balancer, not at 16% protein. So 1lb is way under-feeding it from a nutrient perspective, not to mention he simply needs a lot more calories than he’s consuming (voluntarily or otherwise).
