I’m betting that you probably have at least one bottle of liniment in your tack trunk. That’s good. Liniments are one aid to keeping horses sound. However, they can do more harm than good if used at the wrong time.
In order to use liniments wisely, you have to understand the basics of what happens when a leg is injured. Injury to any living tissue always results in inflammation, and from your own personal experience you know what that means: redness, heat, swelling, and pain. The redness and heat are due to the sudden increase of blood to the area. The swelling is caused by blood and fluids moving into the injured area. The blood that gathers at the injury site is rich in white blood cells and healing proteins. The increased pressure from the fluids affects nerve endings, and causes pain. The pain is important to insure that the limb is favored and rested. The redness will only be seen in horses if they are light colored and the hair has been clipped or shaved. Inflammation seems like a setback, but it’s a good thing. Without it, healing doesn’t happen.
For a real life scenario, let’s assume that a youngster that you have been working comes up lame. You check out his legs, and right under the knee, on the inside of one leg he flinches when you squeeze. He probably has a splint, and within a short period of time the area will show all those signs of inflammation. It is then that many horse owners make the mistake. Because they want to do something, anything, to stop the swelling and lameness they reach for that bottle of liniment and start sloshing it on the sore leg. Not good.
The dark red color of most liniments is from iodine in solution. Iodine is an irritant. When rubbed on a leg it increases blood supply to the area. If the liniment is strong enough, it will also cause swelling and pain to the point of blistering the skin. In other words, the liniment itself is causing inflammation! Remember that the body’s response to injury is inflammation, and it really doesn’t need any help doing that. By causing further inflammation we are aggravating the situation. It’s like throwing gasoline on a fire that you are trying to put out.
At the beginning of this article I said that liniments are good, and they are, but only if used at the proper time. The rule of thumb is always, always to cool an acute condition and apply heat to a chronic one. When a leg has been recently injured, keep the liniment in your tack trunk. The first aid is to use cold therapy. Sit on a lawn chair, let your horse nibble grass, and cold hose that injury. A very fine spray is all you need. Hose the area for 10 to 15 minutes and repeat several times through the day. There are all kinds of strap on flexible boots that hold ice that also work, but they are expensive and require a lot of fussy adjusting. Cooling a leg out requires days, and sometimes weeks of attention. Antiinflammatory medicines like Banamine, Butazolidine, or Previcox are also helpful in calming things down, but are not a substitute for cold therapy.
After leg injuries have been cooled down, they often reach a static phase. The heat is mostly gone, but the pain and some swelling persist. Now is the time that liniments are helpful. They increase the blood supply to the area and really do speed up healing.
Using a liniment too soon aggravates the injury, and makes pinpointing the injured area more difficult. I am reminded of June, a new horse owner whose mare had come up lame. June had a large economy bottle of Absorbine liniment in her trunk and started to rub it on the mare’s right front leg. She wasn’t sure just what hurt, so she rubbed it in from the shoulder right down to the foot. Then she stood back and thought, “Well, I’m not exactly sure where this soreness is coming from. Maybe it’s the other leg, so I’ll rub some there too.” June used up the entire bottle. This particular mare is a chestnut, who, in general seem to have more sensitive skin than other colored horses. Within a few hours both legs started to swell, and I was called out. By the time I got there the mare was miserable. Both massively swollen front legs had a crusty covering of dried liniment over the irritated skin. There was no way to tell where the initial lameness was coming from because she was sore all over. It took another two weeks before we could even begin to deal with the initial issue.
Another problem with using liniments before a diagnosis is that after the liniment dries, the iodine takes on its natural crystalline form which shows up on X-rays as a cloudy area. This makes reading through it difficult, and sometimes impossible.
If you have an injured leg, do your horse and your vet a favor by staying away from liniments until the problem has been diagnosed and cooled out. Then, and only then are they helpful.
–David A. Jefferson, DVM