Typically, carrots are a safe snack for horses. However, there are a few things to keep in mind before offering carrots as a regular feed. Carrots contain high levels of beta carotene, which can help to promote eye health in horses. However, excessive intake of beta carotene can also lead to excess equine eyesight problems. So if your horse regularly consumes large amounts of carrots, it may be best to limit their intake or switch them over to another type of food that is rich in beta carotene (like kale).
Additionally, some horses may be sensitive to the beta carotene found in carrots. If your horse shows any signs of digestive issues after eating carrots— diarrhea, gas, bloating—then it may be best not to offer them as a regular feed item. If you do decide to give carrots as a snack occasionally to your horse, make sure they are served in small quantities and monitored closely by a qualified professional.