OBJECTIVE To describe the use of CT in the diagnosis of and presurgical planning for equids with keratomas treated by hoof wall resection and determine postoperative complications and outcome.
DESIGN Retrospective case series.
ANIMALS 29 horses and 3 mules with keratomas treated by partial or complete hoof wall resection following CT imaging of the distal portion of the affected extremity from 2005 through 2016.
PROCEDURES For each equid, physical examination and lameness evaluation were performed, followed by imaging of the distal portion of the affected extremity. A tentative diagnosis of keratoma was made given results of clinical, radiographic, and CT examination, with the definitive diagnosis made on histologic examination. After CT imaging, each equid was treated with hoof wall resection.
RESULTS CT allowed accurate identification of the size and location of 35 keratomas in 33 feet. Thirty equids underwent partial and 2 underwent complete hoof wall resection for keratoma removal. Complications developed in 4 of 31 (13%) equids and included excessive granulation tissue formation at the surgical site (n = 1), excessive granulation tissue formation and worsening lameness (1), incomplete keratoma removal with suspected regrowth (1), and incomplete healing of the surgical site with distal interphalangeal joint sepsis secondary to repeated debridement of abnormal tissue (1). Twenty-eight of 31 (90%) equids returned to their previous activity level.
CONCLUSIONS AND CLINICAL RELEVANCE Preoperative CT examination of the feet was useful in the diagnosis of and surgical planning for keratomas in equids. A low complication rate was achieved with the described techniques.
OBJECTIVE To evaluate the use of a laparoscopic specimen retrieval pouch for removal of intact or fragmented cystic calculi from standing horses.
DESIGN Retrospective case series.
ANIMALS 8 horses (5 geldings and 3 mares) with cystic calculi.
PROCEDURES Physical examination and cystoscopic, ultrasonographic, and hematologic evaluations of urinary tract function were performed for each horse. A diagnosis of cystic calculus was made on the basis of results of cystoscopy and ultrasonography. Concurrent urolithiasis or other urinary tract abnormalities identified during preoperative evaluation were recorded. Horses were sedated and placed in standing stocks, and the perineum was aseptically prepared. Direct access to the urinary bladder was gained in geldings via perineal urethrotomy or in mares by a transurethral approach. Calculi were visualized endoscopically, manipulated into the retrieval pouch, and removed intact or fragmented (for larger calculi).
RESULTS For 4 geldings and 1 mare, fragmentation was necessary to facilitate calculus removal. Mean duration of surgery was 125 minutes, and trauma to the urinary bladder and urethra was limited to areas of hyperemia and submucosal petechiation. No postoperative complications were encountered for any horse. When lithotripsy was required, the retrieval pouch provided an effective means of stabilizing calculi and containing the fragments for removal.
CONCLUSIONS AND CLINICAL RELEVANCE Use of the laparoscopic specimen retrieval pouch was an effective, minimally traumatic method for retrieving cystic calculi from standing horses. The pouch protected the urinary bladder and urethra from trauma during calculus removal and allowed for stabilization, containment, and fragmentation of calculi when necessary.
To determine period prevalences of postmortem diagnoses for spinal cord or vertebral column lesions as underlying causes of ataxia (spinal ataxia) in horses.
2,861 client-owned horses (316 with ataxia [ataxic group] and 2,545 without ataxia [control group]).
The medical records database of the University of California-Davis Veterinary Medical Teaching Hospital was searched to identify horses necropsied between January 1, 2005, and December 31, 2017. Results were compared between the ataxic and control groups and between various groups of horses in the ataxic group. Period prevalences were determined for the most common causes of ataxia.
2,861 horses underwent full necropsy, and the period prevalences for the most common definitive diagnoses for ataxia were 2.7% (77/2,861) for cervical vertebral compressive myelopathy (CVCM), 1.3% (38/2,861) for equine neuroaxonal dystrophy or equine degenerative myeloencephalopathy (eNAD-EDM), and 0.9% (25/2,861) for trauma; the period prevalence of ataxia of unknown origin was 2.0% (56/2,861). Horses in the ataxic group (vs the control group) were more likely to have been warmblood horses (OR, 2.70) and less likely to have been Arabian horses (OR, 0.53). In the ataxic group, horses < 5 (vs ≥ 5) years of age had greater odds of CVCM (OR, 2.82) or eNAD-EDM (OR, 6.17) versus trauma or ataxia of unknown origin. Horses in the ataxic group with CVCM were more likely Thoroughbreds (OR, 2.54), whereas horses with eNAD-EDM were more likely American Quarter Horses (OR, 2.95) and less likely Thoroughbreds (OR, 0.11).
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that breed distributions differed for horses with CVCM versus eNAD-EDM; therefore, breed should be considered in the clinical evaluation of spinal ataxia in horses.
A 6-year-old Quarter Horse gelding used for barrel racing was evaluated for acute onset of non–weight-bearing lameness of the left hind limb following strenuous exercise.
Nuclear scintigraphic imaging revealed focal increased radiopharmaceutical uptake centrally within the left talus. Subsequent standard radiographic and ultrasonographic examinations of the tarsus failed to identify the cause of the increased radiopharmaceutical uptake; however, the lameness was definitively localized to the tarsocrural joint by intra-articular anesthesia. Subsequent MRI sequences of the left tarsus revealed an incomplete fracture of the talus that extended distally from the trochlear groove and evidence of maladaptive stress remodeling of the trochlear groove of the talus and distal intermediate ridge of the tibia.
TREATMENT AND OUTCOME
The horse was treated conservatively, with management consisting of stall confinement, physical rehabilitation, therapeutic laser therapy, and intra-articular autologous conditioned serum administration. The lameness resolved, and the horse was competing at its previous level within 15 months after lameness onset.
Although rare, incomplete fracture of the talus should be considered as a differential diagnosis for horses that develop acute hind limb lameness following strenuous exercise, especially when that exercise involves abrupt changes in direction while the horse is traveling at maximal speed. Acquisition of additional oblique projections during radiographic evaluation of the tarsus might be useful for identification of such fractures, but definitive diagnosis may require advanced diagnostic imaging modalities such as CT and MRI. Horses with incomplete fractures of the talus can be successfully treated with conservative management.
To describe the etiologies, clinicopathologic findings, diagnostic modalities employed, treatments, and outcome associated with cases of septic bicipital bursitis.
CLINICAL PRESENTATION AND PROCEDURES
Medical records of horses diagnosed with septic bicipital bursitis between 2000 and 2021 were reviewed. Horses were included if synoviocentesis of the bicipital bursa revealed a total nucleated cell count of ≥ 20,000 cells/µL with a neutrophil proportion of ≥ 80%, a total protein concentration of ≥ 4.0 g/dL, and/or the presence of bacteria on cytology, or positive culture of the synovial fluid. Information retrieved from medical records included signalment, history, clinicopathologic variables, diagnostic imaging findings, treatment, and outcome.
Trauma was the most common inciting cause (n = 6). Synoviocentesis using ultrasonographic guidance was performed in all cases and showed alterations consistent with septic synovitis. Radiography identified pathology in 5 horses, whereas ultrasonography identified pathology in all horses. Treatment consisted of bursoscopy (n = 6) of the bicipital bursa of which 1 was performed under standing sedation, through-and-through needle lavage (3), bursotomy (2), or medical management alone (2). Five (55.6%) horses survived to discharge. Long-term follow-up was available for 3 horses and all were serviceably sound, with 2 in training as pleasure horses and 1 case continuing retirement.
Ultrasonography was the most informative imaging modality and paramount in obtaining synovial fluid samples for definitive diagnosis of septic bicipital bursitis. Bursoscopy performed under standing sedation is a feasible treatment option. Horses treated for bicipital septic bursitis have a fair prognosis for survival and may return to some level of athletic performance.
OBJECTIVE To describe clinical use of a locking compression plate (LCP) for proximal interphalangeal joint (PIPJ) arthrodesis in horses and compare outcomes for horses that underwent the procedure as treatment for fracture of the middle phalanx (P2) versus other causes.
DESIGN Retrospective case series.
ANIMALS 29 client-owned horses.
PROCEDURES Medical records of 2 veterinary teaching hospitals from 2008 through 2014 were reviewed to identify horses that underwent PIPJ arthrodesis of 1 limb. Signalment, surgical, and outcome-related variables were recorded. Owners were contacted from 1 to 6 years after surgery to determine rehabilitation time, current use of the horse, and overall owner satisfaction with the procedure. Success was determined on the basis of owner satisfaction and outcome for intended use. Variables of interest were compared statistically between horses that underwent surgery for P2 fracture versus other reasons.
RESULTS 14 horses underwent surgery for treatment of P2 fracture, and 15 had surgery because of osteoarthritis, subluxation, or osteochondrosis. Median convalescent time after surgery (with no riding or unrestricted exercise) was 7 months. Four horses were euthanized; of 23 known alive at follow-up, 22 were not lame, and 18 had returned to their intended use (8 and 10 at higher and lower owner-reported levels of work, respectively). Horses undergoing arthrodesis for reasons other than fracture were significantly more likely to return to their previous level of work. Twenty-two of 24 owners contacted indicated satisfaction with the procedure.
CONCLUSIONS AND CLINICAL RELEVANCE Surgical arthrodesis of the PIPJ was successful in most horses of the study population. Various nuances of the system for fracture repair need to be understood prior to its use.
Objective—To assess clinical outcomes and scintigraphic findings in horses with a bone fragility disorder (BFD) treated with zoledronate (a nitrogen-containing bisphosphonate).
Design—Prospective uncontrolled clinical trial.
Animals—10 horses with evidence of a BFD.
Procedures—Signalment, history, and geographic location of horses' home environments were recorded. Physical examinations, lameness evaluations, and nuclear scintigraphy were performed. Diagnosis of a BFD was made on the basis of results of clinical and scintigraphic examination. Each horse was treated with zoledronate (0.075 mg/kg [0.034 mg/lb, IV, once]) at the time of diagnosis. Horses were reevaluated 6 months after treatment.
Results—Affected horses were from the central and coastal regions of California and had ≥ 1 clinical sign of the disorder; these included scapular deformation (n = 2), lordosis (1), nonspecific signs of musculoskeletal pain (1), and lameness that could not be localized to a specific anatomic region (9). All horses had multiple sites of increased radiopharmaceutica uptake during initial scintigraphic evaluation of the axial skeleton and bones of 1 or both forelimbs. Six months after treatment, clinical improvement (defined as improvement in the lameness score, resolution of signs of musculoskeletal pain, or both) was detected in 9 of 10 horses; scintigraphic uptake was unchanged (n = 2) or subjectively decreased (8). No adverse effects attributed to zoledronate treatment were detected.
Conclusions and Clinical Relevance—Treatment with zoledronate appeared to be useful in improving clinical outcome and scintigraphic findings in horses with a BFD; however, future placebo-controlled studies are necessary to accurately determine efficacy and long-term safety.
To assess the value of F-sodium fluoride (18F-NaF) positron emission tomography (PET) for imaging the tarsus and proximal metatarsus and compare it with CT and lameness evaluation.
25 horses with lameness localized to the tarsal and proximal metatarsal regions that underwent 18F-NaF PET/CT between 2016 and 2021.
18F-NaF PET and CT images were retrospectively independently evaluated by 3 observers. Standardized uptake values (SUV) were used to characterize 18F-NaF uptake. Correlation between PET and CT findings with subjective and objective maximum (Max-D) and minimum pelvic height lameness data was estimated.
The inter-observer Kappa-weighted value (κ) was higher for PET (κ = 0.66) than CT (κ = 0.6). CT and PET scores were fairly correlated (R = 0.49; P < 0.05). PET SUVratio (SUV of the main lesion/SUV talus) had the highest correlation with Max-D (R = 0.71; P < .05). PET and CT scores for the plantar region were significantly higher in Quarter Horses (P < .05) and showed consistently higher correlation with objective lameness data (CT plantar grade - Max-D [R = 0.6; P < .05], PET plantar grade - Max-D [R = 0.47; P = .04]) than other regions of the distal tarsal joints. Three Warmbloods presented marked uptake at the medial cochlea of the distal tibia.
PET had a moderate correlation with CT for assessment of tarsal lesions. The degree of PET uptake can help differentiate active versus inactive lesions. Specific location of the uptake is important in determining clinical relevance.