A three year-old miniature stallion presented to PHD Veterinary Services for the complaint of open mouth breathing and a "honking" sound during respiration. At presentation, the stallion was agitated and was continuously pawing at his muzzle with his mouth open. The stallion was mildly sedated for the endoscopic exam and interestingly, his breathing became more normal. The most proximal trachea (Figure 1) appeared normal in diameter however the lumen quickly became narrowed (Figure 2). The trachea was nearly completely collapsed for approximately 6 cm at the level of the thoracic inlet. Distal to this area, the trachea appeared normal (Figure 3).
 |
| Figure 1 |
 |
| Figure 2 |
 |
| Figure 3 |
Normally, the lumen of the trachea is continuous, extending from the larynx to the primary bifurcation of the trachea (Figure 4). Unfortunately, the miniature horse breed is predisposed to the condition known as collapsing trachea. The condition is often diagnosed shortly after birth or can develop later in life if the horse is allowed to gain excessive weight. A common clinical complaint is that of a "honking" sound during heavy respiration. The severity of the collapsing trachea depends on the location and the extent of the narrowed lumen. The closer the area of collapse is to the chest cavity, the worse the prognosis. There are reported cases of collapsing tracheas in miniature horses that were repaired via intra- and extra-luminal stents. Unfortunately, they are short term fixes and often do not provide a long term solution.
 |
| Figure 4 |
No comments:
Post a Comment