A stabled or inactive horse or pony can suffer from filled legs when the water balance between the horse's circulatory system and its body tissue becomes unbalanced.
This unbalance is often caused by feeding the horse or pony too much protein in its diet and not gving him enough exercise which upsets the balance between protein and the blood salts.
The filling or swelling is usually more noticeable in the horse's lower limbs as gravity causes more pressure in the blood vessels.
One of the best methods for reducing swelling in legs is exercise. So, unless your vet has advised box rest for your horse, turning him out as for as long as possible will help.
Cleavers is a herb that can be added to the horse's feed which can be effective in treating filled legs. Marigold is also useful as it promotes healing.
Massage can be used to stimulate the horse's lymphatic and circulatory systems. This can work well to reduce the swelling in filled legs especially if the massage is carried out with an oil which contains one or more stimulating essential oils such as ginger, marjoram. rosemary, peppermint or spearmint.
Acupuncture, a traditional chinese medicine using needles, can also be used to stimulate the lymphatic and circulatory systems in a horse.
Magnotherapy for horses using equine magnetic boots to treat filled legs can work very well on some horses. The theory behind magnptherapy is that the magnetic current opens up the blood vessels and improves the horse's circulation.
Hosing the horse's legs with cold water is a traditonal method of treating filled legs which works well
Homeopathic treatments for filled limbs - generally it is recommended to use Apis for a horse that likes the cold, and to try Apocynum for a horse or pony which prefers warm conditions.