Haggis the pony had a rough life. He was highly overweight, and his hooves were allowed to get severely long. As a result, he was unhealthy and lame, and it was difficult for him to walk with his long hooves. Horses need regular farrier care to maintain their hooves and keep them an appropriate length. Fixing Haggis' hooves took time and the attention of a talented farrier.
But there's a happy ending; Haggis is much healthier now and has found a new home that gives him the care he needs. Unfortunately, that's not the case for all horses.
According to Equus Magazine, if you suspect that a horse is being neglected, it is important to get the right authorities involved in the situation. Never trespass on a property and never attempt to remove a horse on your own. Instead, document the neglect. Take videos and photos from a public area, if possible. Be sure to get the correct address so that authorities can find the property, and if there is a certain horse in question, write down any identifying marks that can be used to tell exactly which horse needs to be examined.
Next, call the authorities. Call your local law enforcement or animal control officer. Explain the situation, and highlight why you are concerned for the horse. Is there lack of water or lack of food involved? Are the horse's ribs protruding? Is the horse in a physically dangerous situation, such as being tied to a tree or being kept in severe weather without shelter? The more details you can provide, the better.
Once you've reported the horse, it's time to let the authorities do their jobs. You can always call back for reports and updates, but the process of evaluating and even seizing a horse takes some time.
If you see a neglected horse, don't turn a blind eye.