Hoof abscesses are a primary cause for a sudden, dramatic lameness. Fortunately, early detection and proper care can bring your horse back to work and feeling better quicker.
Abscesses are infections under the sole of the foot. Bacteria invade the hoof, either through a puncture wound (such as through a close nail or a hot nail placed during shoeing) or natural separations between live sole and the hard outer wall. As the horse bears weight, debris gets packed up into difficult to see crevices. Once inside the hoof capsule, the bacteria invade the tissue and cause inflammation.
The horse’s immune system recognizes the bacteria and debris as foreign, setting off a reaction that draws white blood cells to the area to fight off the infection. The surrounding tissue is digested by bacterial and cellular enzymes, forming a grayish-black pus. This pus is Hoof abscess – nail in hoofencapsulated within the confined space of the hoof wall, which creates increasing pressure and excruciating pain. Many horses will avoid bearing any weight at all on an abscessed foot, so pain management is an important aspect to consider when helping your horse through this difficult time.
Learn to feel for the digital pulses on your horse’s feet on a normal day. These can be found at the back of the fetlock, alongside the sesamoids or behind the pastern. Running your fingers back and forth, you should be able to feel a few cords of tissue running down to the horse’s foot on either side of the back of the leg. Once you find these ‘cords’, slowly let off pressure and you will be able to detect a pulse. Since the horse has a slow heart rate, you must be patient to feel the pulse. When a horse has an abscess, these pulses are bounding or much more easily felt. The side of the hoof which has the abscess is usually warmer and has a stronger pulse. If the abscess has been brewing for a couple of days, some soft tissue swelling may be seen starting to run up into the pastern and fetlock areas.
Hoof testers are used to put pressure on the sole of the foot to help locate the abscess–the most sensitive area is usually directly over the abscess site. Sometimes a tract Close up – Nail in hoofcan be found where the debris entered the foot, which can be followed in order to open up and drain the abscess. This can provide immediate relief. If the abscess is deep within the hoof, a specific location might not reveal itself on hoof testers. These tend to rupture out of the path of least resistance, which may be the coronary band or the bulbs of the heel. Sometimes you can feel along the coronary band and the bulbs of the heel to locate a softer, warmer spot that is especially painful for your horse. That spot is where the abscess is most likely to rupture and drain.
Soaking the foot in warm water with Epsom salts and a little splash of Betadine is the first step, especially if the foot is too hard to find the abscess tract. Generally 5 days of soaking the foot is sufficient; soaking the foot too many days in a row may actually dry out and damage the hoof wall. A hoof poultice is a better tool to draw out an abscess. Concentrating treatment on the site most likely to rupture can be better for the integrity of the rest of the hoof and speed up healing time.
Most abscesses rupture within a few days, but some can take 2-3 weeks to rupture. Stubborn hoof abscesses may need to be radiographed to see if the infection can be visualized and to confirm the proper diagnosis.
FVEP veterinarians carry AnimaLintex poultice pads that can be moistened and attached to the bottom of the foot with Vetrap. A homemade poultice can be fashioned by making a sugar and iodine paste smeared onto a disposable baby diaper. Equine supply stores will usually have a pre-made hoof poultice ointment available–the one with Epsom salts is my personal favorite. Abscess at coronetIchthammol can also be used as a drawing agent, although it tends to be messy. (Horse stuff–messy? No way!) The tabs on the disposable diaper can be wrapped around the foot and kept in place by using Vetrap and duct tape.
I make a poultice ‘booty’ by putting about 6-7 rows of duct tape (depending on the size of the bottom of the horse’s foot) slightly overlapping each other vertically, and then add a horizontal layer of overlapping strips to that. This covering can be made ahead of time, and can be stuck to the stall wall near where you’re working for easy access. Center the covering flat on the sole of the foot, then press the excess edges of the tape onto the hoof wall, forming a booty’. Wrap a few strips of duct tape around the hoof wall to keep the edges down, and you’ve got a poultice that is water proof and usually withstands the wear and tear a horse will put on it for the next day.
Prevention of hoof abscesses revolves around maintaining the healthy sole-to-wall junction (the white line). This is best done by keeping your horse on a regular hoof trimming schedule. When the toe gets too long, it places stress on the white line. Horses with poor foot conformation or chronic laminitis are most prone to abscesses. Excessive moisture or dryness in the environment affects the health of the foot. Hoof hardeners (such as Keratex or venice of turpentine) can be used to harden the sole of the feet in wet conditions. In dry weather, moisturizers (such as HoofFlex or Corona) can be applied to the hooves to soften them.