Thursday, December 27, 2012

Long toe/Under run heel!!

The image below is of a horse's foot that is suffering from a conformational problem known as "long toe-under run heels". This horse tends to grow significant amount of hoof wall within 4-5 weeks without growing normal heel. Although the heel regions grow, they tend to roll under the center of the hoof. As such, this horse and others like him are prone to heel pain and poor performance. In Figure 1 the center of rotation is marked by the blue line. Ideally, the length of foot that is in front of the blue line and behind should be equal. This would result in a horse that is balanced "cranial to caudal" with respect to the center of rotation. 


Figure 1

As the amount of foot behind  (B) or caudal to the center of rotation decreases compared to "A" there is  a significant increase in the amount of force that is applied across the heel regions. This results in the rolling under or "under run heels" that is imaged in Figure 1 and 2. When this horse is trimmed, the hoof wall needs to be trimmed back to the widest portion of the frog.  This may seem counter intuitive due to the apparent "lack of heel" however it is necessary to achieve "normal" heel growth. 
Figure 2

The radiograph below is that of horse that has heel pain and is lame when trotted in a small circle in both directions. The hoof tester exam noted a strong positive response across the bar region of both heels. Notice that the length of "B" is significantly shorter than "A". In order to correct this problem, corrective shoeing is a must!  The process begins with a balanced trim that includes lowering the heels to the widest portion of the frog. This is followed by applying a shoe that either has built-in break over such as a natural balance/equilibrium shoe or break over is increased manually be rolling the toe. In addition  the shoe is set extra full in an attempt to increase the length of "B" and hence support the caudal aspect of the foot. 
Figure 3

In Figure 4 the horse has been trimmed and re-set. Notice that the length of  "B" is nearly the same as "A". This horse is quite close to being balanced with regard to the center of rotation (blue line) and within 4-5 days returned to complete soundness. Finally, these horses that tend to have a long toes and under run heels need to be trimmed and re-set every 4-5 weeks. It is quite common that these horses are sound for the first 4 weeks after the farrier visit yet their performance begins to diminish as 5 to 6 weeks pass before they are trimmed and re-set. Although radiographs are not necessary to diagnose this problem, they are helpful for quantifying the extent of imbalance and documenting improvement after shoeing. 
Figure 4




Thursday, December 13, 2012

Round Two!! Pharyngeal Phythiosis

Figure 1
The endoscopic image in Figure 1 is from a middle aged quarter horse that presented for abnormal noise during exercise. The entire pharynx is obstructed by multiple granulomas.  Initial biopsy results were consistent with pythiosis and the gelding was treated with systemic anti-fungal medication for several months. 

Figure 2
Recheck endoscopy after 45 days revealed a significant improvement (Figure 2) ; however, treatment was discontinued prematurely and a final endoscopy was not performed.

Figure 3

Over 1 year after the initial presentation, the abnormal noise returned along with bloody nasal discharge. The pale yellow nodules have increased in size and number. Multiple small yellow granuoles are noted through out the pharynx and there is evidence of mild bleeding. The horse will again be treated with systemic anti-fungal medication. A follow up exam to follow!!

Thursday, December 6, 2012

Displaced Soft Palate!!

Figure 1
The image above is an endoscopic pic of a middle-aged gelding that presented for a history of exercise intolerance. Apparently, during low level, forced exercise, the gelding would begin to make loud "gurgling" noises and become short of breath! In addition, the gelding would cough on a regular basis, especially when eating in the stall. 

Figure 2

 The image above is that from a normal horse. The yellow arrow is pointing to the epiglottis which is not visible in Figure 1 and Figure 3 due to the dorsal displacement of the soft palate. Normally, horses breathe through their nasal passages. The epiglottis helps keep the soft palate in position thus keeping the oral pharynx separate  from the nasal pharynx. However, when the soft palate becomes displaced and covers the epiglottis, the nasal pharynx and oral pharynx communicate directly. When this occurs, the horse suddenly begins to breath through its oral cavity which results in a gurgling sound and exercise intolerance.

Figure 3
The cause of the chronic dorsal displacement of the soft palate in this case is in part due to chronic inflammation of the soft palate (yellow arrow) and potentially an abnormal epiglottis (blue star). The epiglottis was not visualized in this exam and may require an oral endoscopy and skull radiographs to better determine if  there is a structural problem with the epiglottis. Management of this condition involves treating with systemic anti-inflammatory medications and medicated throat wash. If the soft palate remains displaced, surgical consultation is recommended. Yet another example of the benefit of an endoscopic exam for a horses that suffer from coughing, exercise intolerance, or nasal discharge.