I have a 20 year old horse who has had swelling on and off in his hind left fetlock. It is not currently swollen, but it has been two times in the last couple of weeks. The first time it went down after a week with stall rest and walking and the second time it went down in a day after just exercising him for a bit. I have had both of his fetlocks injected in June because he refused to canter to the left at all and he flexed lame when the vet came out on them He is also cow hocked and has been resting his his hind toes recently. When the fetlock does swell, he is a tad stiff on it but there is no heat or noticeable lameness. Does anybody have ideas or similar experiences? Should I call the vet since this has happened two times already?