Results suggest that enforced rest without surgical fixation can be an effective therapeutic option for horses with a slab fracture of the central or third tarsal bone, even if athletic function is expected.

The frontal, caudal maxillary, and rostral maxillary sinuses of 10 equine cadavers were examined endoscopically, and the findings were confirmed by sinusotomy. Similar endoscopic examinations were performed in five conscious, adult horses by using sedation and local anesthesia. Useful portals of entry for the arthroscope in adult horses were: for the frontal sinus, 60% of the distance in a lateral direction from midline to the medial canthus and 0.5 cm caudal to the medial canthus; for the caudal maxillary sinus, 2 cm rostral and 2 cm ventral to the medial canthus; and for the rostral maxillary sinus, 50% of the distance from the rostral end of the facial crest to the level of the medial canthus and 1 cm ventral to a line joining the infraorbital foramen and the medial canthus. The frontal sinus portal was most useful for examination of the frontal and caudal maxillary sinuses. The caudal maxillary sinus portal was most useful for examining the sphenopalatine sinus. Structures in the frontal and caudal maxillary sinuses could be approached surgically by viewing them through the frontal sinus portal and guiding an instrument to them through the caudal maxillary sinus portal. Tooth root identification was reliable for the second and third upper molars in animals older than 5 years, but was more difficult for the rostral teeth and in younger animals. Endoscopy was not difficult to perform and was well tolerated in standing, sedated horses. The only complication of this procedure was mild, local subcutaneous emphysema that resolved spontaneously within 14 days.

Sixteen horses with suspected paranasal sinus disease had endoscopic examination of the paranasal sinuses with a 4.0 mm arthroscope either while standing and sedated (14 horses) or under general anesthesia (two horses). Endoscopic diagnosis included sinusitis (four horses), sinus cyst (three horses), hemorrhage (three horses), neoplasia (three horses), and tooth root abnormalities (two horses). No abnormalities were detected in one horse. Endoscopic findings concurred with the radiographic findings in 13 horses (81%). Samples of sinus contents for bacteriologic (eight horses) and histologic examinations (five horses) were obtained using sinus endoscopy. Diagnostic sinus endoscopy was combined with debridement, lavage, and suction as a therapeutic technique in 10 horses. In three horses, sinus exploration was performed after diagnostic endoscopy confirmed sinus disease, whereas in three horses, further therapy was not recommended after sinus endoscopy. Clinical signs of sinus disease resolved in 11 horses (69%) overall and in eight of 10 horses (80%) with sinusitis, cyst formation, or hemorrhage using endoscopic techniques alone. Mild, local subcutaneous emphysema occurred at the portal sites in all horses, but healing occurred without additional complications. Iatrogenic damage to sinus structures occurred in one horse. Sinus endoscopy was useful in the diagnosis and management of paranasal sinus disease and avoided the need for exploratory sinusotomy in some horses.

Duration of colic prior to admission was statistically associated with patient survival to discharge. Other factors significantly associated with survival in mares with large colon volvulus were related to disease severity and degree of colonic compromise. Mares with large colon volvulus have a good prognosis for recovery with early referral and prompt surgical treatment.

A 7-year-old female Thoroughbred was admitted with a history of labored breathing, stridor, and exercise intolerance. Examination revealed a mass in the left paranasal sinuses that was determined to be an ossifying fibroma. Initial treatment consisted of surgical removal of the mass alone; however, the mass recurred 9 months after surgery. The mass was again removed, and adjunctive radiotherapy consisting of 3,000 cGy of cobalt radiation was administered. This time, the tumor did not recur for > 6 years. A third surgery was performed to remove the mass, and adjunctive radiotherapy consisting of 4,000 cGy of photon beam radiation from a linear accelerator was administered. The mass did not recur during the subsequent 3 years. Ossifying fibromas are uncommon tumors that frequently recur if incompletely excised. Results in this horse suggest that adjunctive radiotherapy may delay or prevent tumor recurrence in affected horses.