Not All Splints Are Created Equal!!

The radiographs below are from the forelimbs of a lame horse. The horse had prominent "bumps" on the inside of both canon bones and only one was sensitive to direct pressure (right front). These bumps were consistent with osseous or bony callous formation over the splint bones which are also know as "splints". The  splints had been present for over 45 days and despite moderate rest, the horse remained lame. Specifically, the horse was lame in the right front limb when trotted in a circle to the left! Careful exam of these "splints" revealed that in addition to being painful to pressure over the callous, the horse was positive to pressure over the suspensory ligament at the level of the fractured splint.

Ultrasound exam of the soft tissue structures near the fractured splint revealed an inflamed suspensory ligament. The image below highlights the suspensory ligament (yellow arrow). The areas of black are consistent with edema/fluid accumulation within the ligament and are adjacent to the bony callous. In addition  to the presence of edema/fluid, the fiber pattern is irregular. These findings are consistent with moderate inflammation of the suspensory ligament, most likely due to physical interference via the bony callous. 

The ultrasound image below compares the left and right suspensory ligaments at the level of the corresponding "splints". A clear difference can be seen between the suspensory ligaments (area under the yellow curves) of the lame leg (RF) versus the non-lame leg.

The horse was scheduled for surgery and the offending splint bone was removed. At the time of surgery, moderate inflammation of the suspensory ligament was confirmed. The gelding underwent an extensive period of rehabilitation consisting of rest and controlled exercise. Three months post surgery the gelding is back to work and completely sound. Special thanks to Dr. Tim Lynch at Peterson and Smith Equine Hospital for his surgical expertise and great collaborative effort!

This case is not unique and reminds us that we should pay close attention to ANY "splint" development. Most often, splints resolve without the development of lameness or significant complications however if the appropriate care is not considered, the likelihood of complications does increase. Appropriate care includes forced rest, ice therapy, topical Surpass, and shockwave treatment.

Venogram!

As discussed in last week's "pic of the week", laminitis or founder is a serious condition in horses that requires aggressive and frequent intervention by a veterinarian-farrier team. The radiographs below are those of a quarter horse gelding with moderate founder and approximately 10 degrees of coffin bone rotation. Although the gelding appears stable, he continues to be lame in the affected foot. Routine radiographic evaluation confirms that there has been no further rotation of the coffin bone but does not explain why the horse remains lame. 

The radiographs below are of the same horse AFTER injecting a radiopaque dye into one of the veins that removes blood from the equine foot. A tourniquet is applied at the level of the fetlock before the injection and this allows for the dye to pool within the venous vasculature. Radiographs are taken immediately after the injection and the current blood supply to the foot can be assessed. 

Careful evaluation of the above image suggests that the horse has adequate blood supply to the entire foot. This is evident by the extensive venous supply (white squiggly lines) that originate near the coronary band and essentially surround the entire foot. However, when the foot was imaged in a dorsal-palmar view (below), there appears to be a decline in blood supply to the inside of the foot versus the outside. The yellow arrows are pointing to the areas in question. Note the subjective decline in blood supply along the right side (inside) compared to the left side (outside)

Although these observations are not 100% definitive, they do suggest a reduction in blood supply to the medial aspect of the hoof. This information is important when considering the horses's prognosis and shoeing recommendations. Venograms can be easily performed in a stall-side setting but do require digital radiography and knowledge regarding the technique. The information gathered from these studies is considered an important piece of the puzzle regarding management of laminitis in the horse.

Founder!

The images below are of those of a horse with chronic "founder" or laminitis. There has been significant deterioration of the coffin bone and severe distortion of the hoof wall capsule. Clearly, there has not been adequate care of this horse's feet by a farrier/veterinarian team. Chronic founder requires careful attention and care by a veterinarian AND a farrier. The changes in coffin bone alignment must be monitored via radiographs and corrective shoeing by the farrier is critical to reduce pain and further deterioration of the foot. 

The images below are of a different horse with chronic founder that resulted in the coffin bone rotating out the bottom of the foot. Unfortunately, this is the end of the road for this horse and his condition resulted in humane euthanasia. This end result can often be avoided however sometimes despite the most attentive veterinarian/farrier team, mother nature has the last say in the matter. 

This post will be the first of several discussing chronic laminitis/founder, so stay tuned!!!

Equine Glaucoma!

The horse below presented as a 20 year-old gelding with a 1 year history of recurring eye cloudiness that was also associated with excessive tearing and squinting. When examined, the horse kept his eye partially shut and there was a moderate tinge of "blue" to the entire surface of the eye. The cornea was stained with fluorescein stain (bright green fluid pooling below the eye ball) for the presence of a corneal ulcer and non was detected. 

Closer inspection of the eye revealed a darker blue band that stretched across the cornea. This band is also known as a corneal striae and is caused by persistently increased ocular pressure.  These findings are consistent with equine glaucoma and indicate a significantly elevated pressures within the eye. The blue tint to the cornea is caused by edema and is also be associated with the increased ocular pressures. As in humans, these horses experience significant discomfort evident by their tearing and constant squinting.  Definitive diagnosis requires measuring the ocular pressure via a tonometer that can be easily performed in a stall with mild sedation. The incidence of equine glaucoma is higher than most suspect and is usually not diagnosed until after significant time has passed. Treatment includes medications to lower the ocular pressure; however, this condition is typically chronic and progressive in horses and often results in the loss of the eye. As a rule, if you find your horse with his eye half way or completely shut, it is strongly recommended that a veterinarian examine the eye and provide immediate medial treatment.