3/14/2010 - Spring is Coming

Vet tip of the Day: Thinking about spring and your horse's feet

Wow, the sun came out and I wasn't wearing 4 layers today.  It was such a wonderful feeling not to feel that chill in my bones.  With spring come those freeze thaw cycles when the ground is frozen in sharp, uneven layers at night only to thaw and turn into a slippery slimey mess during the day.  For many of us our horse's turn out areas are a mess this time of year. Particularly around feeders and water troughs, footing tends to be wet during the day and frozen at night.

Because our soil is usually so dry, our horse's feet are adapted to a dry environment.  After a long wet winter as we've had this year, the manure and urine soaked into high traffic areas where horses stand a lot, combined with the freeze/thaw cycles, create a bad formula for our horses feet.  This time of year I see LOTS of severe subsolar abscesses, particularly in older horses.  Here's what happens: first, the horse living in a dry desert climate typically has a hard, somewhat brittle sole.  Over the winter, if the horse's environment is not kept clean and dry, then wet, manure packed material accumulates in the sole and along the sulci of the frog.  This material is full of bacteria.  It softens the frog which becomes recessed, thereby leaving the sole in direct contact with the ground.  The horse steps on a frozen jagged mud edge, creating a tiny defect in the sole which provides access for bacteria to infiltrate into the foot.  The bacteria become trapped beneath the hard sole where there is no air supply.  They begin to proliferate, spreading between the natural layers of the sole.  In response to the bacterial proliferation, the body mounts an inflammatory response, resulting in the accumulation of pus.  Eventually this pus produces enough pressure within the hoof that the horse becomes acutely severely lame.

At this point the sole must be removed to allow drainage of the dead tissue and expose the area to air.  In the worst case scenario, it is possible for the bacteria to migrate far enough into the hoof to cause infection of the coffin bone, although this is NOT the typical outcome.  Once the dead sole is removed exposing the area where the bacteria have infiltrated, with appropriate treatment the sole will harden and repair itself without long term complications.  However, subsolar abscesses are extremely painful, and can be frustrating and time consuming to treat, especially in horses living in outdoor settings.

Prevention is worth a pound of cure, and subsolar abscesses that occur secondary to poor footing conditions during the winter are preventable. First, be sure your horse has regular farrier care.  Second, PICK YOUR HORSES FEET OUT THOROUGHLY EVERY DAY!  Third, try to keep the area around feeders and water troughs as dry as possible, and remove manure from these areas.  If this is not possible,  using a tooth brush rub strong iodine (7%) into your horse's soles and frog several times a week after you clean out the feet.  Following these three simple rules may save you and your horse a major aggravation.  Again, this problem is especially prevalent in older, less active horses, so don't forget about the feet of the retirees, even though they are no longer performance horses.