Omega Alpha Pharmaceuticals has been formulating equine supplements for decades. The Biotic 8 isn’t a one-strain probiotic thrown into a bag of powder. It packs eight distinct strains of live bacteria, plus three digestive enzymes, all specifically designed to survive the harsh environment of a horse’s stomach.

The real trick here is the carrier system. Many probiotics get destroyed by stomach acid before they ever reach the hindgut. This formula protects the microbes through that acidic journey, so they actually arrive where they can colonize and support digestion. The 2.2-pound tub also includes spirulina and kelp as micronutrient boosters, which add trace minerals and amino acids without adding filler. The individual pellets measure just 0.39 by 0.79 inches, making them easy to mix into a standard grain ration.

This is a Dover Saddlery brand product, which means it passed internal quality checks for use on their own horses. It works best as a daily maintenance supplement for horses on high-grain diets or those recovering from antibiotics. The only real limitation is the 2.2-pound size—it covers roughly a one-month supply for a full-sized horse, so you will be reordering regularly.