Canaliculosinostomy as a Long-Term Treatment of Seven Horses for Permanent Obstruction of the Nasolacrimal Duct.

OBJECTIVE: To describe canaliculosinostomy performed to resolve epiphora caused by nasolacrimal duct obstruction and to report the outcome of horses undergoing this procedure. STUDY DESIGN: Case series. ANIMALS: Seven horses with uni- or bilateral nasolacrimal duct obstruction. METHODS: The ventral lacrimal punctum and canaliculus were expanded with catheters of increasing diameter until a 14 gauge, Jamshedi needle could be passed into and through the lacrimal sac into the caudal maxillary sinus. One end of a plastic tube was inserted through the needle into the sinus, and the needle was withdrawn over the tubing. Using a hubless needle, the other end of the tube was passed through the lower eyelid leaving a segment of tubing exposed ventral to the eyelid. The end of the tubing within the sinus was exteriorized through a trephine hole in the frontal sinus and then tunneled beneath the skin adjacent to the osteotomy using a hubless needle, leaving a segment of tubing exposed on the forehead. Exposed tubing was sutured to the skin. The tubing was removed at 5-6 weeks. RESULTS: Canaliculosinostomy was easily performed with the horses sedated. Five horses had resolution of epiphora, and 2 had improvement. CONCLUSION: Canaliculosinostomy to divert lacrimal secretions into the sinuses resolves or improves epiphora caused by nasolacrimal duct obstruction and provides a good functional and cosmetic outcome. Canaliculosinostomy can be performed in the sedated horse.

Subtotal ostectomy of impinging dorsal spinous processes in 23 standing horses.

OBJECTIVES: To (1) describe a safe, efficient surgical technique for subtotal ostectomy (SO) of diseased dorsal spinal processes (DSP) of the caudal thoracic vertebrae with the horse standing and (2) report outcome. STUDY DESIGN: Case series. ANIMALS: Horses (n = 23) with reduced performance caused by impingement of the DSP of the caudal thoracic vertebrae. METHODS: Affected DSP were resected through a dorsal median incision with the horse standing, sedated, and the surgical site desensitized with local anesthetic. Radiography was used to confirm removal of impinging bone before wound closure. RESULTS: No serious complications occurred. Outcome was obtained for 22 horses. At <1 year, 19 horses (86%) returned to full athletic function, 2 horses (9%) improved but had failed to return to full function, 1 horse had no improvement. At >1 year, 2 horses that had returned to full athletic function were unable to function at full capacity; 1 was considered improved, but the other had not improved. Athletic function in 1 horse improved 6 months after surgery, but at 2.5 years was no better than before surgery. CONCLUSIONS: Subtotal ostectomy of impinging DSPs can be performed with good results with the horse standing.

Hypospadias in a Friesian gelding.

OBJECTIVE: To report clinical signs and management of hypospadias in a horse. STUDY DESIGN: Clinical report. ANIMAL: A 6-year-old, Friesian gelding. METHODS: Partial phallectomy was performed to resolve contact dermatitis of the pelvic limbs and abnormal behavior during urination. Subsequent urethral meatal stenosis was treated by revision. RESULTS: Hypospadias and chordee caused altered direction of urine flow, contact dermatitis of the pelvic limbs, and abnormal behavior. Partial phallectomy and subsequent revision after meatal stenosis resolved urine direction, flow and abnormal behavior. CONCLUSIONS: Abnormalities of the urinary tract associated with hypospadias can result in urine-induced, contact dermatitis and distress during urination, but these complications can be resolved by partial phallectomy.

Repair of an incompetent urethral sphincter in a mare.

OBJECTIVE: To describe successful surgical treatment of urinary incontinence caused by a ruptured and/or transected urethral sphincter in a mare. STUDY DESIGN: Clinical report. ANIMAL: A 7-year-old, Swedish Warmblood mare with urinary incontinence. METHODS: The urethral sphincter, which had been damaged during removal of a cystic urolith, was repaired by apposing the ends of the disrupted urethralis muscle and tunica muscularis. RESULTS: The mare was no longer incontinent after repair of the defect by apposition of the ends of the urethralis muscle and tunica muscularis. CONCLUSIONS: Transection and/or rupture of the urethral sphincter of a mare may result in urinary incontinence. CLINICAL RELEVANCE: Apposition of the ends of the ruptured or transected urethralis muscle and tunica muscularis can correct urinary incontinence caused by this defect.

Association between clinical signs and histopathologic changes in the synovium of the tarsocrural joint of horses with osteochondritis dissecans of the tibia.

OBJECTIVE: To develop a scoring system for histopathologic changes in the synovium of tarsocrural joints (TCJs) of horses with osteochondritis dissecans (OCD) and to test for association between histopathologic changes and joint effusion or lameness. ANIMALS: 93 horses with OCD of the intermediate ridge of the tibia of 1 or both TCJs (134 joints) and 38 control horses without disease of TCJs (38 joints). PROCEDURES: For OCD-affected horses, pretreatment lameness, TCJ effusion, and results of pelvic limb flexion test were scored. Synovial biopsy specimens were obtained from TCJs of OCD-affected horses during arthroscopy, and similar postmortem tissue specimens were obtained from control horses through a small arthrotomy. Histologic signs of synovitis in 172 biopsy specimens were scored by 2 pathologists (A and B) by use of 2 criteria: synoviocyte proliferation and cellular infiltration. RESULTS: Analysis of scoring revealed good to very good intraobserver agreement within pathologist A (weighted kappa [WK], 0.76 to 0.81), and moderate to good agreement within pathologist B (WK, 0.56 to 0.63). Interobserver agreement for synoviocyte proliferation (WK, 0.34 to 0.52) and cellular infiltration (WK, 0.38 to 0.48) scores was fair to moderate. Joint effusion and synoviocyte proliferation were significantly associated, as were joint effusion and cellular infiltration. There was no association between histopathologic changes and the other clinical signs evaluated. CONCLUSIONS AND CLINICAL RELEVANCE: The scoring system was helpful for evaluating synovial inflammation caused by OCD of the intermediate ridge of the tibia in horses. Histopathologic signs of synovial inflammation were associated with effusion but not with lameness.

Surgical correction of wry nose in four horses.

OBJECTIVE: To describe surgical techniques used for correction of congenital nasal deviation (wry nose) in horses (wry nose) and to report outcome. STUDY DESIGN: Retrospective study. ANIMALS: Horses (n=4), 5-17 months old with wry nose. METHODS: Nasal deviation was corrected by transecting the premaxillae/maxillae and nasal bones at their site of maximum curvature and realigning and stabilizing the bones in a more normal alignment using internal fixation. The nasal septum was removed during the same anesthetic period. RESULTS: For each horse, physical appearance was improved and respiratory stridor eliminated. CONCLUSIONS: Wry nose can be corrected by transecting the premaxillae/maxillae and nasal bones and stabilizing the transected bones in a more normal alignment; the nasal septum can be removed concurrently. CLINICAL RELEVANCE: Surgical correction of wry nose may provide a good functional and cosmetic outcome.

Changes in synovial fluid biomarker concentrations following arthroscopic surgery in horses with osteochondritis dissecans of the distal intermediate ridge of the tibia.

OBJECTIVE: To quantify concentrations of cartilage oligomeric matrix protein (COMP) and fibromodulin in synovial fluid from the tarsocrural joints (TCJs) of horses with osteochondritis dissecans (OCD) of the distal intermediate ridge of the tibia and determine whether concentrations would change following arthroscopic removal of osteochondral fragments. ANIMALS: 115 client-owned horses with OCD of the TCJ and 29 control horses euthanized for unrelated reasons. PROCEDURES: COMP and fibromodulin concentrations were measured in synovial fluid from the TCJs of the affected horses before and after osteochondral fragments were removed arthroscopically and in synovial fluid from the TCJs of the control horses after euthanasia. Synovial biopsy specimens from the TCJs of affected and control horses were examined histologically for evidence of inflammation. RESULTS: Synovial fluid COMP and fibromodulin concentrations prior to surgery in horses with OCD were not significantly different from concentrations in control horses. Fibromodulin, but not COMP, concentration in horses with OCD was significantly decreased after surgery, compared with the concentration before surgery. Fibromodulin concentration was significantly correlated with joint effusion score but not with lameness score or results of a flexion test and was correlated with histologic score for number of synoviocytes on the surface of the synovium but not with score for degree of infiltration of inflammatory cells in the synovium. Synovial fluid COMP concentration was not significantly correlated with clinical or histologic findings. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that fibromodulin, but not COMP, could potentially be a biomarker of joint inflammation in horses with OCD of the TCJ.

Levator labii superioris muscle transposition to treat oromaxillary sinus fistula in three horses.

OBJECTIVE: To describe surgical transposition of the levator labii superioris muscle to treat oromaxillary sinus fistula in horses. STUDY DESIGN: Clinical study. ANIMALS: Three horses with chronic oromaxillary sinus fistula. METHODS: After severing its tendinous insertion, the muscle belly of the levator labii superioris muscle was retracted and transposed through the oromaxillary sinus fistula. The tendon exited the oral cavity through a full-thickness buccal incision created adjacent to the oral end of the fistula and was then tunneled subcutaneously in a ventral direction before being anchored by sutures to the cheek tissues. RESULTS: Fistulae healed with few complications and with good cosmetic and functional results. CONCLUSIONS: Oromaxillary sinus fistula associated with molariform tooth loss in horses can be treated successfully by transposition of the levator labii superioris muscle. CLINICAL RELEVANCE: Transposition of the levator labii superioris muscle should be considered for resolution of chronic oromaxillary sinus fistula in horses.