An Abundance of Abscesses

Things have been busy at Clinton Veterinary Service! In addition to the “routine” calls, we've seen an increase in nasty foot abscesses recently. This is not particularly surprising in light of all the wet weather and mud Michigan has experienced, but can be very concerning to owners because the horse can progress from normal to three-legged lame very quickly. 

One of the hoof abscess cases we saw presented initially like a case of laminitis; we were called out to see a 20 year old gelding with severe lameness in his front left leg. The owner had recently started turning the horse out on fresh pasture for several hours a day, and when we arrived he was in a “toe-pointing” stance, holding the lame limb forward with only the toe touching the ground and shifting his weight to his hind limbs as much as possible. The farrier had been to the farm recently and had noticed some mild lameness, but could not identify any abscesses in the hoof. We performed a physical exam and as much of a lameness exam as the horse would allow. There appeared to be a small draining tract and a black spot on the sole of the foot, near the toe, which Dr. Trombley inferred may indicate an abscess the farrier had caused to partially drain. Pairing away the sole in this area revealed a deep draining tract and only a small amount of pus. The gelding was not more comfortable after opening this area, so we continued examining him with the hoof testers to identify any other sensitive areas. Unfortunately he reacted strongly no matter where the hoof testers were placed on the front left limb, making it difficult to identify the issue. In order to rule out laminitis and hopefully identify the issue, we took radiographs of both front feet. The hoof radiographs revealed no signs of rotation to P3, often referred to as the coffin bone, which would have been indicative of laminitis. Instead we saw the draining tract Dr. Trombley had opened at the toe and further evidence of abscesses. Dr. Trombley began to carefully pair away the sole along the white line to look for the abscesses, which proved to be deep and quite impressive once found. 

No evidence of P3 rotation. (Sorry for the poor quality image)

Essentially, as the sole was paired away the abscess  began to drain along the white line along the entire lateral half of the hoof. When Dr. Cynthia set the hoof down for approximately a minute, there was a small pool of black fluid on the cement when she picked the hoof up again. I had never seen so much fluid expressed from a hoof abscess. The photo below indicates some of the black pus draining from the sole (red arrows). 

 We treated the hoof with a product called CleanTrax that cleanses the hoof of bacteria and fungi without damaging the sensitive tissue of the hoof. We mixed the CleanTrax with a gallon of water and soaked the hoof for 45 minutes. The instructions indicated that after the initial soak, the solution should be poured out on the stall bedding material and the horse left tied to stand in the vapors for an additional 45 minutes. Dr. Trombley says she has had good success with this product for bad cases of hood abscess and white line disease.

The owner was instructed to keep the hoof padded with nitrofurazone and DMSO gel and wrapped with daily changes until there was no more drainage evident on the padding material. After 3 days the owner called to say the gelding was considerably more comfortable within 24 hours and there was no more evidence of drainage on the wrap material.

Apart from the profound amount of drainage, this case is fairly representative of many of our emergency farm calls because hoof abscesses can be so painful and occasionally baffling to localize.

In my next post, I hope to share a bit about the cases of Potamic Horse Fever we've already seen this summer.
Until then,
-Valerie