Case Description—A 2-year-old Quarter Horse was evaluated because of a progressive left-sided facial deformity and unilateral nasal and ocular discharge.
Clinical Findings—Physical examination revealed convexity of the left frontonasal region, left-sided nasal and ocular discharge, and decreased air flow through the left nares. Radiography and computed tomography revealed an extensively mineralized mass occupying most of the left paranasal sinuses.
Treatment and Outcome—The mass was surgically debulked, but complete removal was precluded because the mass was tightly adhered to the frontal and maxillary bones. Results of histologic examination of the mass were consistent with a diagnosis of osteoma. The horse developed transient pyrexia and colic following surgery, and postoperative radiography revealed gas opacities in the lateral ventricles of the brain, consistent with iatrogenic pneumocephalus. However, the horse did not develop any neurologic signs and was performing normally 2 years after surgery.
Clinical Relevance—Findings reinforce concerns that paranasal sinus surgery in horses can be associated with intracranial complications such as pneumocephalus. In horses with a mass involving the paranasal sinuses, computed tomography may be helpful in determining the boundaries of the mass and formulating a surgical treatment plan.
Case Description—A 3-year-old Thoroughbred mare was evaluated because of abnormal upper respiratory tract sounds (that had become apparent during race training) of 3- to 4- months' duration.
Clinical Findings—On initial physical evaluation, there were no abnormal findings. During trotting, an abnormal upper airway expiratory sound was audible. Endoscopic examination revealed a small mass protruding into the right ventral nasal meatus. Radiographic images of the skull revealed no abnormal findings. Computed tomography of the head revealed an abnormal structure in the same location as the mass that was observed during endoscopy. The x-ray attenuation of the mass was identical to that of dental tissue.
Treatment and Outcome—The mass was surgically removed with endoscopic guidance. On gross examination, the excised mass appeared to be a nearly normal molariform tooth. Histologic examination revealed that it was a well-formed tooth, with no other associated cellular populations. The mass was determined to be a molariform supernumerary intranasal tooth. Six months following discharge from the hospital, the trainer reported that the abnormal respiratory tract sound was no longer audible. During a follow-up endoscopic examination performed at the training facility, no abnormalities were detected.
Clinical Relevance—In horses, an intranasal tooth should be considered as a differential diagnosis for expiratory stridor. Clear definitions of heterotopic polyodontia, dentigerous cyst, and temporal teratoma can be used to clinically diagnose these separate anomalies. In the horse of this report, computed tomographic findings contributed to determination of a diagnosis and formulation of a treatment plan.
Objective—To determine history; clinical, radiographic, ultrasonographic, and scintigraphic features; management; and outcome associated with third trochanter fractures in horses.
Design—Retrospective case series.
Procedures—Records from 2000 to 2012 were reviewed, and signalment, case history, severity and duration of lameness, results of physical and lameness examinations, imaging findings, management, and outcome were evaluated.
Results—All horses had a history of acute onset of severe lameness. Four of the 8 horses had localizing physical signs of fracture. No specific gait characteristics were identified. Ultrasonographically, there was a single bony fragment displaced cranially in 7 of 8 horses and multiple bony fragments in 1. Concurrent gluteus superficialis muscle enthesopathy was identified in 7 horses. A standing craniolateral-caudomedial 25° oblique radiographic view was obtained in 3 horses to document the lesion and revealed in all 3 horses a simple complete longitudinal fracture between the midlevel and the base of the third trochanter. Nuclear scintigraphy was used to identify the affected area of the limb for further examination in 2 horses. Follow-up revealed that fractures healed with a fibrous union, with persistence of cranial displacement of the fragment. Lameness resolved after nonsurgical management for all horses.
Conclusions and Clinical Relevance—Fracture of the third trochanter should be considered as a cause of hind limb lameness in horses when the proximal portion of the limb is affected. Diagnosis can easily be made with ultrasonography, but nuclear scintigraphy may help in identifying the lesion. Prognosis for return to athletic activity is good after an appropriate period of rest and restricted exercise.