Years ago working on the farm (Hobeau) and taking care of over a hundred barren and maiden mares I quickly became acquainted with foot abscesses. Having no formal, or for that manner, any training in how to approach and care for these I quickly learned that for the most part they take care of themselves. The horse usually shows a progressive 2-4 day lameness, is three legged lame one day, and almost sound the next day with a usual discharge from the coronary band.
Subsequent to that adventure I was a licensed veterinarian and practicing in South Florida where the horses run around in a very moist soil conditions with underlying coral rock: I got to treat, and mistreat a lot of foot abscesses. There was some important takeaways:
First anti-inflammatories such as bute delay the maturation of the abscess. In many cases the abscess instead of staying localized will undermine the whole sole and frog before escaping either proximally through the coronary band or distal through the sole. Secondly if you must pare away the foot going after the problem do not touch the sole but go up the white line. Soles take forever to grow back.
Modern digital X-ray machines easily diagnose a foot abscess. In the picture above the arrow points to a circular darkened area which represents a pocket of fluid. A good pair of hoof testers also helps diagnose an abscess . Hoof testers can also delineate a hot nail from a bruise/abscess.A digital pulse is almost always present. In large warm bloods sometimes this can be tricky but with thoroughbreds it’s pretty easy to feel the pulse.
Treatments are as mentioned benign neglect, soaking in hot water with epsom salts, and packing/bandaging the foot with ichthammol or animal lintex. On some rare occasions I have caught an abscess early enough and in a critical time frame environment (e.g. Public auction) to successfully treat with intravenous tetracycline. Tetracycline is extremely caustic to a vein if it gets outside the vein. I caution people to get veterinary assistance in administering the medication.
Sometimes there can be complications or perhaps it wasn’t an abscess but a puncture wound.The horse’s foot pictured below has an infection get into the coffin bone and one can see a significant area of the bone has disappeared. (The black area below the pointer)
These horses typically don’t resolve the lameness in a fairly short period of time in which radiographs are indicated to look for these type of complications. This horse was a referral but recovered to full health with regional limb perfusion therapy and long term antibiotics.
April 3, 2017
H.O. Ferguson, DVM