Horses are herbivores. It is natural for them to eat herbs. In their natural environment, horses graze and they readily eat various herbs while they grow. Herbs such as Comfrey, Red Clover and even wild Garlic will often be sought out and eaten when they are available. However, even in the "good old days" not all useful herbs were growing in the green pastures since each require differing climates to be at their best. This has meant that traditionally herbs have been supplemented to the diet.