Abscesses can come on rapidly and cause startling lameness: Your horse was fine when you turned him out this morning, but he’s come in from the field three-legged lame. So lame, in fact, that you have a sinking feeling he may have broken something.  

While breaks in the field are a possibility, the most-likely culprit of your hobbling horse is an abscess. Caused by bacteria entering the hoof capsule, abscesses increase pressure within the hoof wall, making every step agony for your equine.

What is an Abscess?

Hoof walls naturally expand and contract, depending on the weather, time of year and health of the hoof. During this expansion and contraction, tiny cracks appear in the hoof wall that can allow bacteria or foreign matter to enter. When these unnatural particles reach the sensitive area of the foot, they set up shop and prepare to hang out for a while. The horse’s body recognizes that this material as something foreign and tries to rid itself of the intruder. In doing so, the horse’s body creates a pocket of pus (abscess) around the matter. This pocket then creates pressure on the structures in the hoof, causing pain.

Signs of an abscess include:

  • A sudden onset of lameness (usually a 2/5 on the lameness scale, or more) is one of the most visible signs of an abscess
  • movement with an altered gait (usually more on their toe or more on their heel) in an effort to alleviate pressure on the painful limb
  • heat in the foot
  • an increased digital pulse in the affected limb
  • positive reaction to hoof testers
  • possible swelling of fetlock or pastern
  • swelling in the heel bulb or coronary band or a vertical ridge that forms on the face of the hoof wall

A horse that is brewing an abscess may have varying degrees of lameness during the onset period, but the lameness becomes constant as the area festers.

In this X-ray, the faint, dark line is the track the abscess is taking in the hoof wall. The line starts at the sole to the left of the letters W and L on the x-ray and comes out just below the coronet band and the sole to the left of the letter L, running parallel to the coffin bone.

When Do Abscesses Appear?

Though abscesses can happen any time of year, they appear most often during periods of prolonged wet weather (wet=mud!). Here at New Vocations, we see abscesses a lot when it’s snowy, but there is enough sun to warm the top portion of the soil, allowing horse hooves to sink deeply into the mud and wet soil. These hoofprints then tend to freeze when temperatures dip at night, forcing the horses to travel over pointy, frozen ground the next day, potentially bruising their feet, before the ground thaws and hooves are again subjected to mud and wet.

The combination of bruising and the softening of the foot causes allows bacteria and debris to enter through cracks in the hoof wall. Usually after two to three weeks of this type of freezing-and-thawing weather, abscesses begin to appear.

The same expansion and contraction of hooves (including cracks) happens when horses are exposed to extended periods of wet weather with mushy ground changing to dry-and-hard ground, then swapping back to wet and muddy (like in the spring).

How an Abscess is Treated

At New Vocations, if we are unsure if a horse is experiencing an abscess or if he has another injury, we will place him on Bute (phenylbutazone) for about three days to see if the lameness abates. If it does not get better, the horse is most likely experiencing an abscess and we proceed to treat him as such.

If you don’t have much experience with abscesses, it can be helpful to call your vet or farrier to find out if that is what is truly making him so lame. In addition, this professional will also be able to help locate exactly where on the hoof the abscess is located; the vet or farrier will use hoof testers and squeeze different areas of the hoof to determine where the horse is most sore. If the horse is shod, they will also decide if the shoe on the affected limb should be pulled to allow the abscess a place to drain; an abscess will always drain out the path of least resistance (which is why we use drawing agents on hooves with abscesses – more on this in a moment). In most cases, the shoe can be put back on when the abscess stops draining.

Treatment for an abscess is the same no matter which foot is affected. A drawing agent like ichthammol or an Epsom salt poultice is applied to the affected area (whether that’s the sole, coronet band or heel bulb). The foot is then padded (baby diapers are the perfect solution!) and wrapped, with additional material like duct tape added for additional pack protection. The hoof will need to be packed each day until the abscess drains.

This image shows where the abscess exited the sole. The horse was non-weight bearing when the abscess was brewing.

We don’t tend to soak the hooves of our horses that have abscesses as we don’t want to soften the entire hoof capsule. We also use a drawing product called AnimalLintex Hoof Poultice, which can be cut to size and applied under the bandage. We purchase some of our hoof packing supplies form Big Dee’s.

You will be able to tell when the abscess “blows” as there will be a smelly, dark area on the padding where the infection has come out through the hoof wall. There may also be a hole or a horizontal crack on the heel bulb or coronary band if that is where the abscess drained. Swelling and pain will be markedly decreased.

While it may seem like the tedious process of wrapping and rewrapping the hoof has come to an end, it’s not quite over yet: In order to prevent more bacteria from becoming trapped in the hole the last abscess has drained from, you’ll need to wrap the hoof for three or four additional days, adding in an iodine-based product to encourage the hoof to harden.

Once the abscess is out and the horse is mostly sound, turnout in a dry area, like an indoor arena, is recommended to keep the horse moving and flushing out the remainder of the bacteria. If no dry, safe turnout is available, handwalking is the next best option.

If the abscess blows out the heel bulb, the heel bulb will remain sore for an extended period of time because the heel bulb has softer tissue; abscesses here may need to be protected for a longer period of time. Horses that have had a heel bulb abscess should not be turned out in mud or on frozen ground for two to three weeks after and their stall should be kept as clean and dry as possible.

Wrapping It Up

Short of keeping your horse in a pristine stall with turnout only on immaculate fields when it’s completely dry, there is no way to truly prevent an abscess from forming. Routine farrier care and a clean, dry stall or area for a horse to stand outside of mud is preferable, as is the ability to stay away from ground that is uneven and frozen. The onset of an abscess is startling and sudden, but thankfully with time and diligence, most abscesses are rectified with minimal complications.

 

Disclaimer: This is NOT a New Vocations horse; we are supplying this video of a horse with an abscess so readers might see how severe the lameness can rapidly become.

 

New Vocations is thankful to Big Dee’s for their support of our mission to rehab, retrain and rehome retiring racehorses. Big Dee’s has committed to donate the equivalent of 5% of all purchases by New Vocations supporters to a New Vocations account through its Bonus Bucks program. All you have to do is designate New Vocations in the comments box or use the code NVRA.  


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