Headshaking in 5 horses after paranasal sinus surgery.

OBJECTIVE: To report headshaking and presumptive trigeminal neuritis as a potential complication after paranasal sinus surgery in horses. STUDY DESIGN: Retrospective case series. ANIMALS: Horses (n = 5) that developed headshaking within 45 days of paranasal sinus surgery. METHODS: Medical records (2007-2010) of horses that had been evaluated for headshaking after paranasal sinus surgery were reviewed. RESULTS: Of 5 horses that developed headshaking within 45 days of paranasal sinus surgery, resolution occurred after treatment in 2 horses. One horse was euthanatized because clinical signs associated with headshaking could not be controlled. Headshaking persisted in the other 2 horses but was either adequately controlled with analgesics or was considered infrequent and transient enough to not warrant therapeutic intervention. Only 2 of 5 horses returned to full work after development of headshaking. CONCLUSIONS: Headshaking because of presumptive trigeminal neuritis is a possible career-ending or fatal complication of paranasal sinus surgery in horses.

In vitro biomechanical comparison of a 4.5 mm narrow locking compression plate construct versus a 4.5 mm limited contact dynamic compression plate construct for arthrodesis of the equine proximal interphalangeal joint.

OBJECTIVES: To compare the in vitro biomechanical properties of a 4.5 mm narrow locking compression plate (PIP-LCP) with 2 abaxially located transarticular screws and a 4.5 mm limited contact dynamic compression plate (LC-DCP) with 2 abaxially located transarticular screws using equine pasterns. STUDY DESIGN: Experimental. Paired in vitro biomechanical testing of 2 methods for stabilizing adult equine forelimb PIP joints. ANIMAL: Adult equine forelimbs (n = 8 pairs). METHODS: Each pair of PIP joints were randomly instrumented with either a PIP-LCP or LC-DCP plate axially and 2 parasagitally positioned 5.5 mm transarticular screws. The proximal aspect of the proximal phalanx (P1) and the distal aspect of the middle phalanx (P2) were embedded to allow for mounting on a mechanical testing machine. Each construct was tested in both cyclic and subsequently single cycle to failure in 4-point bending. The displacement required to maintain a target load of 1 kN over 3600 cycles at 1 Hz was recorded. Maximum bending moment at failure and construct stiffness was calculated from the single cycle to failure testing. RESULTS: In cyclic testing, significantly more displacement occurred in the LC-DCP (0.46 ± 0.10 mm) than for the PIP-LCP (0.17 ± 0.11 mm) constructs (P = .016). During single cycle testing there was no significant difference in the bending moment between the LC-DCP (148.7 ± 19.4 N m) and the PIP-LCP (164.6 ± 17.6 N m) constructs (P = .553) and the stiffness of the LC-DCP (183.9 ± 26.9 N mm) was significantly lower than for the PIP-LCP (279.8 ± 15.9 N/mm) constructs (P = .011). All constructs failed by fracture of the bone associated with the transarticular screws and subsequently bending of the plates at the middle hole. CONCLUSIONS: Use of the PIP-LCP resulted in a stiffer construct of the same strength as the LC-DCP in vitro using this 4-point bending model.

Long-bone fractures in llamas and alpacas: 28 cases (1998-2008).

Treatment and outcome of camelids with long-bone fractures are described. Medical records (1998-2008) of camelids (n = 28) with long-bone fractures were reviewed for signalment, time to presentation, fracture type, method of repair, duration of hospitalization, and post-operative complications. Follow-up information was obtained via telephone interviews with owners. Mean age and weight at presentation were 3.4 years and 56.3 kg, respectively. Twenty-six fractures were treated with internal fixation (n = 11), external fixation (n = 10), combination of internal and external fixation (n = 3), amputation (n = 1), and external fixation followed by amputation (n = 1). Long-term follow-up information was obtained for 19 of the 26 animals. The post-operative complication rate was 23% and owner satisfaction was high. Animals with open fractures were more likely to experience complications. Internal fixation was associated with superior alignment and outcome. Internal fixation techniques should be recommended for camelids.

Computed tomography or magnetic resonance imaging-assisted partial hoof wall resection for keratoma removal.

OBJECTIVES: To (1) describe the computed tomography (CT) and magnetic resonance imaging (MRI) appearance of keratomas; (2) describe a CT- or MRI-assisted partial hoof wall resection technique for removal of keratomas; and (3) evaluate the morbidity and postoperative outcome of these horses. STUDY DESIGN: Case series. ANIMALS: Horses (n=10) with keratoma. METHODS: Data retrieved from medical records included signalment, lameness duration and grade, physical and diagnostic evaluation findings, CT and MRI technique and findings, surgical details, histopathologic diagnosis, postoperative treatment, and complications experienced. Long-term outcome was obtained by telephone interviews of owners. RESULTS: Complications including excessive granulation tissue formation and infection were seen in 2 horses (20%). No keratoma recurrence occurred. Follow-up information was available for 8 horses; 7 were sound and had resumed work. Mean time until they became sound was 2.7 months, and mean time until work resumed was 3.6 months. CONCLUSIONS: CT and MRI can be used to accurately identify the location of keratomas. Postoperative complications may be decreased by creating smaller hoof wall defects, filling the defects with antimicrobial-impregnated polymethylmethacrylate, and placing a shoe early in the postoperative period.

Percutaneous endovascular retrieval of an intravascular foreign body in five dogs, a goat, and a horse.

CASE DESCRIPTION-5 Dogs, 1 goat, and 1 horse underwent percutaneous endovascular retrieval of intravascular foreign bodies between 2002 and 2007. CLINICAL FINDINGS-Foreign bodies were IV catheters in 4 dogs, the horse, and the goat and a piece of a balloon valvuloplasty catheter in 1 dog. Location of the foreign bodies included the main pulmonary artery (1 dog), a branch of a pulmonary artery (4 dogs), the right ventricle (the goat), and a jugular vein (the horse). TREATMENT AND OUTCOME-The procedure of percutaneous endovascular retrieval of the foreign body was easy to perform in all instances. One dog was euthanized 41 days after retrieval because of worsening of another disease process, and 1 dog had abnormal neurologic signs secondary to a brain mass. All other animals were clinically normal during the follow-up period (follow-up duration, 3 to 57 months). None of the animals developed long-term complications secondary to the foreign body retrieval procedure. CLINICAL RELEVANCE-Intravascular foreign bodies that result from catheters or devices used during minimally invasive techniques are rare but may cause substantial morbidity. Percutaneous endovascular retrieval of intravascular foreign bodies was easily and safely performed in the 7 animals reported here. Use of percutaneous endovascular retrieval techniques should be considered for treatment of animals with intravascular foreign bodies because morbidity can be substantially decreased; however, proper selection of patients for the procedure is necessary.

Comparison of magnetic resonance contrast arthrography and arthroscopic anatomy of the equine palmar lateral outpouching of the middle carpal joint.

The objective of this report was to provide an anatomic description of the equine palmar lateral outpouching of the middle carpal joint by comparing its arthroscopic and magnetic resonance (MR) contrast arthrography appearance and to define the structures within the palmar lateral outpouching of the middle carpal joint that can be assessed arthroscopically. MR contrast arthrography was performed on seven cadaveric limbs; images were compared with those obtained during arthroscopic exploration of the palmar lateral outpouching of the middle carpal joint. Gross dissection was performed to confirm identification of intra-articular structures. The MR images compared well with the arthroscopic and gross appearance of the palmar lateral outpouching of the middle carpal joint. Portions of the ulnar carpal bone, fourth carpal bone, fourth metacarpal bone, lateral palmar intercarpal ligament, and lateral collateral ligament of the carpus were identified within the palmar lateral outpouching of the middle carpal joint in all limbs. In addition, in three limbs areas of the third carpal bone and intermediate carpal bone could be seen. MR arthrography was a useful tool for helping to define the anatomy of the palmar lateral outpouching of the middle carpal joint. The arthroscopic approach to the palmar lateral outpouching of the middle carpal joint is technically easy, but the intra-articular anatomy can be confusing. Use of a motorized arthroscopic blade to remove excess synovial tissue is necessary to view all of the structures within the palmar lateral outpouching of the middle carpal joint. Arthroscopic removal of osteochondral fragments from this location may be facilitated by the information obtained from this study.

Palmar carpal osteochondral fragments in racehorses: 31 cases (1994-2004).

OBJECTIVE: To evaluate records of racehorses with palmar carpal osteochondral fragments and determine whether the fragments were indicators of the severity of pathologic joint changes or prognosis. DESIGN: Retrospective case series. ANIMALS: 31 racehorses. PROCEDURES: Medical records, radiographs, and videos of arthroscopic procedures were reviewed. Information gathered included signalment; location, number, and size of the primary lesion; number and size of palmar carpal fragments; and details pertaining to surgical procedures. Outcome variables were obtained from race records. RESULTS: 31 horses met the selection criteria. Multiple palmar fragments were diagnosed in 58% of horses; small fragments (< 3 mm in diameter) were most common (52% of horses). Fifty-two percent of the horses returned to racing, 48% returned to racing and earned money, and 32% had at least 5 more starts. Horses with multiple fragments had significantly less earnings per start and lower performance index values after surgery than those with 1 fragment. Horses with palmar fragments < 3 mm in diameter were significantly less likely to return to racing and have 5 starts or to win money after surgery than horses with larger fragments. CONCLUSIONS AND CLINICAL RELEVANCE: Palmar carpal osteochondral fragments can be used as an indicator of clinically important joint pathology and as a prognostic indicator in racehorses. Horses with multiple small fragments were less likely to successfully return to racing than horses with only dorsally located carpal fragments or horses with 1 or 2 large palmar fragments. When possible, removal of palmar carpal osteochondral fragments should be considered.

Bilateral ureterocystostomy to correct left ureteral atresia and right ureteral ectopia in an 8-month-old standardbred filly.

OBJECTIVES: To report the diagnosis and outcome after surgical correction of bilateral distal ureteral anomalies in a Standardbred filly. STUDY DESIGN: Clinical case report. ANIMAL: An 8-month-old, 310 kg Standardbred filly with left ureteral atresia and right ureteral ectopia. METHODS: The filly was admitted for evaluation of incontinence since birth and severe urine scalding of the hindquarters. Diagnosis was made by both direct (cystoscopy and vaginoscopy) and indirect (intravenous pyelography, ultrasonography, and scintigraphy) evaluation of the ureters and bladder. The filly had left ureteral atresia, hydronephrosis, and decreased left-sided renal function and right ureteral ectopia before surgery. Surgical correction was performed on the left by an end-to-side stapled anastomosis technique and on the right by a side-to-side hand-sewn anastomosis technique. RESULTS: Surgical correction was successful. The filly had no postoperative complications and remained continent 18 months after surgery. Left renal function improved. CONCLUSION: Ureteral anomalies can be successfully repaired in larger (>300 kg) foals and some renal function may be restored after surgical correction. CLINICAL RELEVANCE: Scintigraphy should be considered in diagnosis of ureteral anomalies, assessing renal function, and determining prognosis for horses with hydronephrosis caused by ureteral ectopia and atresia.

West Nile virus encephalomyelitis in horses: 46 cases (2001).

OBJECTIVE: To determine signalment, clinical findings, results of diagnostic testing, outcome, and postmortem findings in horses with West Nile virus (WNV) encephalomyelitis. DESIGN: Retrospective study. ANIMALS: 46 horses with WNV encephalomyelitis. PROCEDURE: Clinical data were extracted from medical records of affected horses. RESULTS: On the basis of clinical signs and results of serologic testing, WNV encephalomyelitis was diagnosed in 46 of 56 horses with CNS signs. Significantly more males than females were affected. Increased rectal temperature, weakness or ataxia, and muscle fasciculations were the most common clinical signs. Paresis was more common than ataxia, although both could be asymmetrical and multifocal. Supportive treatment included anti-inflammatory medications, fluids, antimicrobials, and slinging of recumbent horses. Results of the IgM capture ELISA and the plaque reduction neutralization test provided a diagnosis in 43 horses, and only results of the plaque reduction neutralization test were positive in 3 horses. Mortality rate was 30%, and 71% of recumbent horses were euthanatized. One horse that had received 2 vaccinations for WNV developed the disease and was euthanatized. Follow-up communications with 19 owners revealed that most horses had residual deficits at 1 month after release from the hospital; abnormalities were resolved in all but 2 horses by 12 months after release. CONCLUSIONS AND CLINICAL RELEVANCE: Our findings were similar to those of previous WNV outbreaks in horses but provided additional clinical details from monitored hospitalized horses. Diagnostic testing is essential to diagnosis, treatment is supportive, and recovery rate of discharged ambulatory horses is < 100%.