Cold therapy is a tested and trusted method to treat any swelling in a horse’s limbs. If your equine has suffered a knee injury, simply buy a good ice pack. Gel packs are generally considered to be more convenient and effective. Make sure to apply the pack within 24 to 48 hours of the injury. However, do not expose the cold to any open wounds. Give a 5 minute after 15 minutes of applying the pack. You’ll eventually see the swelling wear down. However, if no results are visible then consult a vet.