It is a frightening site to go out to the barn and see your horse standing still holding up his foot.  You try to move him and he acts as though his leg is broken.  You start to panic as just this morning he ran up to his feed bucket. Take a deep breath though as the most common cause of this lameness is a foot abscess.  It’s not broken but it feels like it to him.

First thing you should do is examine the leg for any cuts, punctures or swellings. Next examine the bottom of the foot for any abnormalities such as holes in the sole, nails or any other debris in the sole or frog.  Feel the hoof walls of both front feet to detect any heat differences.  The next thing to check for is a bounding digital pulse at the back of the pastern.  Make a C shape with your thumb and forefinger and grasp the pastern area with the web of you hand around the front of the pastern and the tips of your thumb and forefinger wrapping around to the back of the pastern.  In a normal foot, you should barely feel a pulse if you can feel one at all. With an inflamed foot, the pulse will be strong and you will feel it push against your finger tips. Practice on your horse beforehand to get a feel for normal.  This will tell you that the pain is definitely within the hoof.  Also, if the abscess is trying to pop out the coronet then the pastern and fetlock may be swollen but pressing on that area will not be painful. Sometimes, lightly tapping on the hoof wall and sole with a screwdriver will give a pain response.

Abscesses are caused by dirt entering the white line and traveling up the wall. They can also be caused by bruising the sole or frog such as by stepping on a rock.  They can also occur after a penetrating foreign body such as a regular nail or even a misplaced shoeing nail. Abscesses occurring at the white line are likely the most common and especially when there are wet conditions. This softens the foot and weakens the white line which is the junction of the hard insensitive laminae and the inner sensitive laminae. This is the area farriers try to avoid when placing the nails.  Poor quality hoof walls such as cracks and splits provide a place for dirt and bacteria to enter.  Once entering, the dirt and/or bacteria travel up the white line and start to fester. The pressure builds up and since the hoof wall is rigid and cannot swell it becomes extremely painful. The pressure follows the path of least resistance and may end up coming out the coronet. However, this takes longer and it is better to try to pull the abscess back out of the white line through the bottom of the foot.  Abscesses caused by sole bruising start with a traumatic insult such as a rock, a bruise forms which is really just bleeding below the surface.  Blood is bacteria’s favorite place to grow and an abscess evolves. Abscesses can be caused by penetrating foreign bodies because the object is obviously not sterile and brings bacteria in with it.  The bleeding that goes along with the injury then provides a place for the bacteria to grow.

If you are still sure that you are dealing with a foot abscess then call your farrier or veterinarian and they can apply hoof tester to locate the painful area on the foot.  They can then attempt to locate the tract at the white line toward the abscess and open it for drainage. You should never dig a hole in the sole, only at the hoof wall, as it will take too long for the sole to heal and the horse must remain bandaged until it does.  If the exact place of the abscess cannot be located or if you veterinarian/farrier cannot make it out that day, there are things you can do to help draw out the abscess.

In the past, it was recommended to soak the foot in hot Epsom salt water for 30 minutes. However, if the foot is already soft from being in wet conditions then this may actually hurt not help. In this situation, you can just wrap the foot with an Epsom salt paste on the sole or my favorite is wrapping the foot with an Animalintex poultice pad on the bottom of the foot.  Animalintex pads run under some hot water will take the place of soaking the foot.  Change this daily until the abscess pops out or the horse becomes sound.  Always wrap the foot for at least 4 days after the abscess comes out as it will leave a hole where it comes out that will allow dirt to reenter.  You may not always see this hole but it is there.  Also, if the pastern is swollen and you can feel a painful area at the coronet that indicates the abscess may be ready to pop out at that spot. Put a little icthammol salve at that spot as well as the poultice on the sole and that may speed it coming out at the coronet.

It’s not always possible to prevent abscesses.  Regular feet trimmings and keeping them out of wet conditions is best. Teach them to stand quietly for the farrier so nails are less likely to be misplaced. Also keep debris and rocks out of their turnout or workout areas. If your horse gets a foreign object in his foot, wrap immediately and call your veterinarian as vital structures may be hit such as the navicular bursa.  If you’re lucky all your horse may need is a bandage and a tetanus booster if it’s been longer than 6 months.

As always, consult your veterinarian with any type of lameness situation that you are not familiar with but don’t panic as broken bones within the foot are far more rare than an abscess. Dr Angela Chenault practices at La Paloma Equine Clinic in Waller and the surrounding counties.