We have teamed up with Dr. Bret Luedke and the team at Heritage Equine to give you a comprehensive article on joint effusion in horses.

Effusion, by definition is an increased amount of fluid within the synovial compartment of a joint. This fluid accumulation can result from inflammation, infection or trauma.

So what exactly does this mean for your horse?  You will typically see effusion as thickening or “filling” of one of your horses joints that may or may not have a lameness associated with it.  The most common reason for effusion in horses is due to arthritis in a joint.  There is normally some fluid in the joint called synovial fluid that helps with lubrication, almost like a motor oil that helps the joint move smoothly.  When there is arthritis in a joint the inflammation caused by the arthritis leads to the normal motor oil to break down into a more water-based fluid.  This fluid isn’t as viscous and therefore doesn’t lubricate the joint as well.  The body tries to correct this by increasing the production of normal motor oil, increasing the amount of fluid in the joint.  This increased fluid or “EFFUSION” is what causes the swelling or filling in the joint.  This increased fluid can cause pain as it stretches out the joint capsule and the pain causes more inflammation which in turn causes more watery-fluid… and the downward cycle continues.

So your horse has effusion, now what? 

This is the foundation to lameness in horses, how do we combat the effects of inflammation in joints? The simplest treatment is rest, allow the tincture of time to let the body heal itself.  While effective, it’s not very fun to watch your horse when you want to be out riding.  The next step is often an anti-inflammatory such as bute which will systemically reduce inflammation.  Often very effective but has its downfalls with excessive, long-term use.  The last step, and the most targeted approach, is to inject a therapeutic directly into the inflamed joint.  These therapeutics can range from steroids to biologics such as IRAP or stem-cells each with their own pluses and minuses.

While there are many other options out there, these are the hallmark treatments used by most veterinarians to treat effusion/ joint problems.  The take-home message being, if you see effusion in your horse’s joint/s it may be a transient issue that works itself out with a little time, but if it lasts more than a few days or if there is any lameness associated with it, it is time to call the vet.  If treatment is needed, the earlier the better.