Comparison of 18 F-sodium fluoride positron emission tomography and computed tomography for imaging of the fetlock in 25 nonracehorses.

BACKGROUND: 18 F-sodium fluoride (18 F-NaF) positron emission tomography (PET) has been validated as a useful imaging technique in the racehorse fetlock. The use of 18 F-NaF PET in the nonracehorse fetlock has not been reported. OBJECTIVES: To describe 18 F-NaF PET findings in nonracehorse fetlocks, to compare with computed tomography (CT) findings and to compare PET findings between horses with and without fetlock pain. STUDY DESIGN: Retrospective observational study. METHODS: All horses undergoing 18 F-NaF PET and CT imaging of the fetlock between October 2016 and March 2021 were included in the study. Medical records were reviewed for associated lameness information. RESULTS: Thirty-six fetlocks (33 front and 3 hind) from 25 horses were included. The interobserver agreement for PET [0.62 (95% confidence interval [CI] 0.59-0.65)] was higher than for CT [0.47 (95% CI 0.43-0.51)]. Increased 18 F-NaF uptake was most common in the medial subchondral bone of the proximal phalanx (23/36), the dorsomedial (20/36) and dorsosagittal (16/36) metacarpal/metatarsal distal subchondral bone, whereas sclerosis was identified on CT in these areas in 22 of 36 (p > 0.9), 33 of 36 (p = 0.001) and 23 of 36 (p = 0.15), respectively. Significant correlations were found between PET grades and both subchondral sclerosis and resorption CT grades (p < 0.001, Spearman r = 0.19 and 0.21, respectively). Abnormal 18 F-NaF uptake in the proximal sesamoid bones (PSBs) was identified in 12 of 36 of the fetlocks, which was more common than CT abnormalities (3/36, p = 0.02). Periarticular increased uptake was seen in 7 of 36 fetlocks, whereas osteophytosis was recognised on CT in 20 of 36 (p = 0.1). Maximal standardised uptake values (SUVmax) were significantly higher in painful than in nonpainful fetlocks (22.0 and 11.9, respectively, p = 0.038). MAIN LIMITATIONS: Retrospective study and limited sample size. CONCLUSIONS: Overall PET and CT findings follow a similar distribution in their location. PET identified more abnormalities in the PSBs than CT. SUVmax is a pertinent factor to take into consideration for the assessment of the clinical significance of findings.

Advances in Regional Vascular Injection Techniques for the Delivery of Stem Cells to Musculoskeletal Injury Sites.

Vascular injections of stem cells are a pertinent alternative to direct intralesional injections when treating multiple or extensive lesions or with lesions impossible to reach directly. Extensive research using stem cell tracking has shown that intra-arterial injections without the use of a tourniquet should be preferred over venous or arterial regional limb perfusion techniques using a tourniquet. The median artery is used for the front limbs and the cranial tibial artery for the hind limbs. Proper efficacy studies are still lacking but early clinical work seems promising.

18F-sodium fluoride positron emission tomography provides pertinent additional information to computed tomography for assessment and management of tarsal pain in horses.

OBJECTIVE: To assess the value of 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) for imaging the tarsus and proximal metatarsus and compare it with CT and lameness evaluation. ANIMALS: 25 horses with lameness localized to the tarsal and proximal metatarsal regions that underwent 18F-NaF PET/CT between 2016 and 2021. METHODS: 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. RESULTS: 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. CLINICAL RELEVANCE: 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.

Establishment of a sequential dual tracer 18 F-NaF/18 F-FDG PET protocol for imaging the equine foot.

The combination of 18 F-Sodium Fluoride (18 F-NaF) and 18 F-FluoroDeoxyGlucose (18 F-FDG) for positron emission tomography (PET) imaging of the equine foot is appealing for detection of both osseous and soft tissue lesions in a single scan. As the combination of tracers could lead to a loss of information, a sequential approach, consisting in imaging with one tracer prior to injecting the second tracer, might be valuable. The goals of this prospective, methods comparison, exploratory study were to establish the order of tracer injection and timing for imaging. Six research horses were imaged under general anesthesia with 18 F-NaF PET, 18 F-FDG PET, dual 18 F-NaF/18 F-FDG PET, and CT. Proper uptake could be identified in tendon lesions as early as 10 min after 18F-FDG injection. Bone uptake was limited when 18F-NaF was injected under general anesthesia, even at 1 h after injection, when compared with 18 F-NaF injection prior to anesthesia. The sensitivity and specificity of the dual tracer scans were 0.77 (0.63 to 0.86) and 0.98 (0.96 to 0.99) respectively, to assess 18 F-NaF uptake and 0.5 (0.28 to 0.72) and 0.98 (0.95 to 0.99), respectively, for 18F-FDG uptake. These results suggest that the sequential dual tracer approach is a pertinent technique to optimize the PET data gained from a single anesthetic episode. Based on dynamics of tracer uptake, the optimal protocol consists in injecting 18F-NaF prior to anesthesia, acquire 18F-NaF data then inject 18F-FDG and start acquisition of dual tracer PET data 10 min later. This protocol should be further validated in a larger clinical study.

In Vitro Generated Equine Hepatic-Like Progenitor Cells as a Novel Potent Cell Pool for Equine Metabolic Syndrome (EMS) Treatment.

Equine metabolic syndrome (EMS) is recognized as one of the leading cause of health threatening in veterinary medicine worldwide. Recently, PTP1B inhibition has been proposed as an interesting strategy for liver insulin resistance reversion in both equines and humans, however as being a multifactorial disease, proper management of EMS horses further necessities additional interventional approaches aiming at repairing and restoring liver functions. In this study, we hypothesized that in vitro induction of Eq_ASCs hepatogenic differentiation will generate a specialized liver progenitor-like cell population exhibiting similar phenotypic characteristics and regenerative potential as native hepatic progenitor cells. Our obtained data demonstrated that Eq_ASCs-derived liver progenitor cells (Eq_HPCs) displayed typical flattened polygonal morphology with packed fragmented mitochondrial net, lowered mesenchymal CD105 and CD90 surface markers expression, and significant high expression levels of specific hepatic lineage genes including PECAM-1, ALB, AFP and HNF4A. therewith, generated Eq_HPCs exhibited potentiated stemness and pluripotency markers expression (NANOG, SOX-2 and OCT-4). Hence, in vitro generation of hepatic progenitor-like cells retaining high differentiation capacity represents a promising new approach for the establishment of cell-based targeted therapies for the restoration of proper liver functions in EMS affected horses.

Evaluating the Safety of Intra-Articular Mitotherapy in the Equine Model: A Potential Novel Treatment for Osteoarthritis.

No current treatments available halt osteoarthritis progression in horses or humans. Intra-articular injection of mitochondria is a novel treatment that has the potential to improve cell metabolism and decrease inflammation, but safety of this treatment has yet to be established in the horse. Autologous blood-derived mitochondria isolated using a commercially available kit were injected into the left carpus joint of 3 horses which were monitored for 28 days. Horses received physical examinations, video recorded gait evaluations, joint diameter measurement, synovial fluid collection, and blood collection on day 0 (baseline prior to mitotherapy, day of mitochondria injection), 1, 3, 7, 14, and 28. Systemic inflammation was assessed via complete blood count, fibrinogen, and plasma serum amyloid A (SAA). Local inflammation was assessed via synovial fluid cytology and physical examination parameters. Physical exam parameters remained stable and no joint swelling was observed after mitotherapy. No change was noted in video recorded gait evaluations as determined by a blinded evaluator. Complete blood counts revealed no significant increase in white blood cells. SAA only increased mildly in 1 horse. Fibrinogen became slightly elevated above reference range in 2 horses at day 7, but later normalized. Mild increases in synovial fluid nucleated cell counts and total protein occurred on day 1 and 3, but resolved within 7 days without intervention. Autologous mitochondria injection into the equine intercarpal joint was well tolerated with no signs of inflammation. This safety information allows for future studies evaluating mitotherapy efficacy.

Therapeutics prior to mesenchymal stromal cell therapy improves outcome in equine orthopedic injuries.

OBJECTIVE: Mesenchymal stromal (stem) cells (MSCs) have been studied to treat many common orthopedic injuries in horses. However, there is limited information available on when and how to use this treatment effectively. The aim of this retrospective study is to report case features, treatment protocols, and clinical outcomes in horses treated with MSCs. ANIMALS: 65 horses presenting with tendinous, ligamentous, and articular injuries, and treated with MSCs prepared by a single laboratory between 2016 and 2019. Outcome information was available for 26 horses. PROCEDURES: Signalment, clinical signs, diagnostic methods, treatment protocol features (prior and concurrent therapies, cell origin, dose, application site and number), and effective outcomes were analyzed. The analysis was focused on comparing the effect of different MSC treatment protocols (eg, autologous vs allogeneic) on outcome rather than the effectiveness of MSC treatment. RESULTS: MSC treatment resulted in 59.1% (clinical lameness) to 76.9% (imaging structure) improvement in horses with diverse ages, breeds, sex, and lesions. The use of other therapeutic methods before MSC application (eg, anti-inflammatories, shockwave, laser, icing, resting, bandage and stack wrap, intra-articular injections, and/or surgical debridement) was shown to be statistically more effective compared to MSCs used as the primary therapeutic procedure (P < .05). Autologous versus allogeneic treatment outcomes were not significantly different. CLINICAL RELEVANCE: A prospective MSC treatment study with standardization and controls to evaluate the different features of MSC treatment protocols is needed. The various case presentations and treatment protocols evaluated can be used to inform practitioners who are currently using MSCs in clinical practice.

Artificial Mitochondrial Transfer (AMT) for the Management of Age-related Musculoskeletal Degenerative Disorders: An Emerging Avenue for Bone and Cartilage Metabolism Regulation.

Musculoskeletal system disorders are among the most common age-related conditions worldwide. All associated with a degeneration of the supporting tissues under pro-inflammatory micro- and macro-environments, the erosion of cartilage and later of bones, are the main hallmarks of these pathologies. Affected chondrocytes, osteoblasts and synoviocytes, that are all critical actors in the bone and cartilage defects exhibit mitochondrial dysfunction that develops immediately following cartilage and bone injury, and leads to tissue residing specific cell death, cartilage degeneration, bone erosion, and ultimately post-traumatic musculoskeletal degeneration. Herein, we would like to introduce a novel concept for bone and cartilage related defects treatment based on artificial transfer of exogeneous functional mitochondria (AMT). Particularly, we believe that because mitochondrial failure critically contributes to degenerative disorders onset and progression, replacing malfunctioning mitochondria with their healthy and functional counterparts can represent a novel, and effective therapeutic solution for the management of bone and cartilage related degenerative diseases. Artificial mitochondrial transfer (AMT) may reverse the failed metabolic status of musculoskeletal tissues cells and reduce bone and cartilage tissues defects by restoring mitochondrial bioenergetics.

Validation of a dedicated positron emission tomography scanner for imaging of the distal limb of standing horses.

A positron emission tomography (PET) scanner, with an openable ring of detectors, was specifically designed to image the distal limb of standing horses. The goals of this prospective, preclinical, experimental, methods comparison study were to validate the safety of the scanner, assess image quality, and optimize scanning protocols. Six research horses were imaged three times (twice standing, once anesthetized) and six horses in active race training were imaged once under standing sedation. Multiple scans of both front fetlocks were obtained with different scan durations and axial fields of view. A total of 94 fetlock scans were attempted and 90 provided images of diagnostic value. Radiotracer uptake was the main factor affecting image quality, while motion did not represent a major issue. Scan duration and field of view also affected image quality. Eight specific lesions were identified on PET images from anesthetized horses and were all also independently recognized on the PET images obtained on standing horses. Maximal standardized uptake values (SUVmax) had good repeatability for the assessment of specific lesions among different scans. Three feet and six carpi were also successfully imaged. This study validated the safety and practicality of a PET scanner specifically designed to image the distal limb in standing horses. Proper preparation of horses, similar to bone scintigraphy, is important for image quality. A 4-min scan with 12 cm field of view was considered optimal for clinical fetlock imaging. Evaluation of a larger clinical population is the next step for further assessment of the clinical utility of PET imaging in horses.

The Hepatic Stellate Cells (HSTCs) and Adipose-derived Mesenchymal Stem Cells (ASCs) Axis as a Potential Major Driver of Metabolic Syndrome - Novel Concept and Therapeutic Implications.

Herein, we would like to introduce a novel concept for the prevention and treatment of metabolic syndrome, which is based on molecular relationship between liver and adipose tissue. Particularly, we believe, that unravelling the molecular crosstalk between hepatokines and adipokines will allow to better understand the pathophysiology of metabolic diseases and allow to develop novel, effective therapeutic solutions against obesity and metabolic syndrome. Inter-organ communication on the level of stem progenitor cells-hepatic stellate cells (HSTCs) and adipose-derived progenitors (ASCs) could represents a key mechanism involved in controlling glucose tolerance as well as insulin sensitivity.

Medial malleolus fragmentation following talocalcaneal arthrodesis by a dorsomedial approach in a horse.

A 16-year-old, Quarter Horse mare was presented for a 3/5 right hind lameness associated with osteoarthritis of the talocalcaneal joint (TCLJ). Positron emission tomography (PET) and computed tomography (CT) demonstrated marked increased uptake of 18F-sodium fluoride and bone remodeling at the medial facet of the TCLJ, respectively. Under general anesthesia 2 cortical screws (4.5 and 5.5 mm) were placed in neutral fashion via an arthrotomy from dorsomedial to plantaromedial through the medial facet of the TCLJ followed by copious lavage of the tarsocrural joint. Eight weeks after surgery, observable effusion of the tarsocrural joint was present and lameness had worsened. Radiographic examination revealed a fragmented medial malleolus of the tibia, likely secondary to repetitive trauma of the screw heads during tarsal flexion. Repeated CT showed partial fusion of the TCLJ. Both screws were removed and the tarsocrural joint was thoroughly lavaged arthroscopically. At a 20-month recheck the lameness had not improved, and ultrasound examination revealed severe thickening of the TCLJ capsule. Recheck examination 48 mo after surgery showed complete fusion of the TCLJ and resolution of the lameness. Key clinical message: Diagnosis of osteoarthritis of the TCLJ is challenging. Management by arthrodesis using a dorsomedial approach can result in fragmentation of the medial malleolus, with secondary synovitis and capsulitis of the tarsocrural joint.

Fragmentation de la malléole médiale suite à une arthrodèse talo-calcanéenne par voie dorsomédiale chez un cheval. Une jument Quarter Horse âgée de 16 ans a été présentée pour une boiterie postérieure droite de 3/5 associée à une arthrose de l'articulation talo-calcanéenne (TCLJ). La tomographie par émission de positrons (TEP) et la tomodensitométrie (CT) ont démontré une augmentation marquée de l'absorption du fluorure de sodium-18F et un remodelage osseux significatif au niveau de la facette médiale du TCLJ, respectivement. Sous anesthésie générale, deux vis corticales (4,5 et 5,5 mm) ont été placées de façon neutre via une arthrotomie dorsomédiale à plantaro-médiale à travers la face médiale du TCLJ suivie d'un lavage abondant de l'articulation tarsocrurale. Huit semaines après la chirurgie, un épanchement significatif de l'articulation tarso-crurale était présent et la boiterie s'était aggravée. L'examen radiographique a révélé une malléole médiale du tibia fragmentée, probablement secondaire à un traumatisme répétitif des têtes de vis lors de la flexion du tarse. La tomodensitométrie répétée a montré une fusion partielle du TCLJ. Les deux vis ont été retirées et l'articulation tarso-crurale a été soigneusement lavée par arthroscopie. Lors d'un nouveau contrôle après 20 mois, la boiterie ne s'était pas améliorée, et l'échographie a révélé un épaississement sévère de la capsule TCLJ. Un nouvel examen 48 mois après la chirurgie a montré une fusion complète du TCLJ et une résolution de la boiterie.Message clinique clé :Le diagnostic de l'arthrose du TCLJ est difficile. La prise en charge par arthrodèse par voie dorso-médiale peut entraîner une fragmentation de la malléole médiale, avec synovite secondaire et capsulite de l'articulation tarso-crurale.(Traduit par Dr Serge Messier).

Factors affecting successful ultrasound-guided injection into the podotrochlear bursa using a palmarolateral approach.

OBJECTIVE: To evaluate potential factors affecting ultrasonographic visibility of the suprasesamoidean region and the success rate of ultrasound-guided injection (USGI) into the podotrochlear bursa (PB). STUDY DESIGN: Ex vivo, experimental study. ANIMALS: 24 cadaveric forelimbs. METHODS: The PB was distended with 0, 1, or 2 ml of iodinated contrast material and saline under radiographic guidance. Ultrasonographic visibility of the suprasesamoidean region and PB was graded before and after distention with the limb loaded in three positions (vertical, cranial and caudal). Two operators with different experience levels performed an USGI into the PB with methylene blue (12 limbs each [four limbs with each of three volumes of PB distension]) using a palmarolateral approach and caudal foot placement. Limbs were frozen and sectioned to assess accuracy. RESULTS: Ultrasonographic visibility scores of the suprasesamoidean region (p = .0081) and PB (p < .0001) were improved using a caudal foot placement. Higher visibility grades of the suprasesamoidean region were associated with higher injection success rate (p = .047). The injection success was 75% (9/12) for the experienced versus 41.6% (5/12) for the less experienced operator (p = .14). PB distension improved visibility during caudal foot placement (p = .013) but not injection success rates (p = .78). CONCLUSION: Caudal foot placement enhances visibility of the PB and suprasesamoidean region. Limbs with poor visibility of the suprasesamoidean region are more likely to undergo a failed USGI. CLINICAL SIGNIFICANCE: The lateral USGI approach should be performed only in cases of optimal visibility. The reported success rates support the technical challenge of PB injections.

18 Fluorine-fluorodeoxyglucose positron emission tomography for assessment of deep digital flexor tendinopathy: An exploratory study in eight horses with comparison to CT and MRI.

Lesions of the deep digital flexor tendon (DDFT) are a cause for foot lameness in horses. Positron emission tomography (PET) could provide valuable information regarding the metabolic activity of these lesions. The aims of this exploratory, prospective, methods comparison study were to assess the ability of 18 fluorine-fluorodeoxyglucose (18 F-FDG) PET to detect DDFT lesions and to compare the PET findings with CT and MRI findings. Eight horses with lameness due to pain localized to the front feet were included. Both front limbs of all horses were imaged with 18 F-FDG PET, noncontrast CT, and arterial contrast-enhanced CT; 11 limbs were also assessed using MRI. Two observers graded independently 18 F-FDG PET, noncontrast CT, arterial contrast CT, T1-weighted (T1-w) MRI, and T2-weighted (T2-w)/STIR MRI. Maximal standardized uptake values were measured. Lesions were found in seven of 16 DDFT on PET, 12 of 16 DDFT on noncontrast CT, six of 15 DDFT on arterial contrast CT, eight of 11 DDFT on T1-w MRI, and six of 11 DDFT on T2-w/STIR MRI. Positron emission tomography was in better agreement with arterial contrast CT (Kappa-weighted 0.40) and T2-w/STIR MRI (0.35) than with noncontrast CT (0.28) and T1-w MRI (0.20). Maximal standardized uptake values of lesions ranged from 1.9 to 4.6 with a median of 3.1. Chronic lesions with scar tissues identified on noncontrast CT or T1-w MRI did not have increased 18 F-FDG uptake. These results demonstrated that 18 F-FDG PET agreed more closely with modalities previously used to detect active tendon lesions, i.e. arterial contrast CT and T2-w/STIR MRI. 18 Fluorine-fluorodeoxyglucose PET can be used to identify metabolically active DDFT lesions in horses.

Fracture Stabilization and Management in the Field.

Management of fractures in the field starts with successful assessment and stabilization of the patient by the practitioner on the front lines. A careful examination is vital to succesful patient management. This includes identifying the fracture location and severity, evaluating skin integrity and potential contamination of the fracture, and treating any ongoing hemorrhage, hypovolemia or stress. Appropriate application of splints in the field will minimize ongoing tissue damage and improve patient comfort. This ultimately aids further assessment, facilitates referral, and improves opportunities for successful fracture repair.

Time required to achieve maximum amikacin concentration in the synovial fluid of the tarsocrural joint following administration of the drug by intravenous regional limb perfusion in horses.

OBJECTIVE: To determine the median time to maximum concentration (tmax) of amikacin in the synovial fluid of the tarsocrural joint following IV regional limb perfusion (IVRLP) of the drug in a saphenous vein of horses. ANIMALS: 7 healthy adult horses. PROCEDURES: With each horse sedated and restrained in a standing position, a 10-cm-wide Esmarch tourniquet was applied to a randomly selected hind limb 10 cm proximal to the point of the tarsus. Amikacin sulfate (2 g diluted with saline [0.9% NaCl] solution to a volume of 60 mL) was instilled in the saphenous vein over 3 minutes with a peristaltic pump. Tarsocrural synovial fluid samples were collected at 5, 10, 15, 20, 25, and 30 minutes after completion of IVRLP. The tourniquet was removed after collection of the last sample. Amikacin concentration was quantified by a fluorescence polarization immunoassay. Median maximum amikacin concentration and tmax were determined. RESULTS: 1 horse was excluded from analysis because an insufficient volume of synovial fluid for evaluation was obtained at multiple times. The median maximum synovial fluid amikacin concentration was 450.5 µg/mL (range, 304.7 to 930.7 µg/mL), and median tmax was 25 minutes (range, 20 to 30 minutes). All horses had synovial fluid amikacin concentrations ≥ 160 µg/mL (therapeutic concentration for common equine pathogens) at 20 minutes after IVRLP. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that, in healthy horses, maintaining the tourniquet for 20 minutes after IVRLP of amikacin in a saphenous vein was sufficient to achieve therapeutic concentrations of amikacin in the tarsocrural joint.

Chondrosesamoidean ligament enthesopathy: Prevalence and findings in a population of lame horses imaged with positron emission tomography.

BACKGROUND: Increased 18 F-Sodium Fluoride (18 F-NaF) uptake at the chondrosesamoidean ligament (ChSL) attachment on the distal phalanx was identified in an exploratory positron emission tomography (PET) study. The prevalence and significance of this lesion has not been previously investigated. OBJECTIVES: The goal of this study was to assess the prevalence of this lesion, its association with other imaging findings and with clinical signs. STUDY DESIGN: Retrospective cross-sectional analytical study. METHODS: All horses with 18 F-NaF PET and computed tomography (CT) imaging of the feet performed between October 2016 and December 2017 were included in the study. All PET scans were independently assessed by two radiologists for increased uptake at the ChSL attachment site and concurrent imaging was reviewed. Clinical findings, treatment and outcome were retrieved from the medical records. RESULTS: Fourteen of 30 horses (20/56 feet) had increased 18 F-NaF uptake in the region of interest. ChSL enthesopathy was the primary lesion in three horses. Other PET abnormalities included navicular bone uptake (13 feet) and ipsilateral palmar process uptake (9 feet). There was no significant association between ChSL enthesopathy and other lesions. ChSL enthesopathy was significantly associated with foot lameness. CT abnormalities at the ChSL attachment were initially identified in one foot, and retrospectively noted in another five following the results of PET imaging. MAIN LIMITATIONS: The study is retrospective and there was a limited sample size. CONCLUSIONS: PET led to identification of ChSL enthesopathy in a large proportion of horses with foot pain. This finding is most commonly associated with other lesions but may also represent the main abnormality. The axial border of the palmar processes of the distal phalanx should be carefully assessed on cross sectional imaging to identify this lesion. ChSL enthesopathy may be an important but previously not recognised component of foot pathology in horses.

Radiological prevalence of osteoarthritis of the cervical region in 104 performing Warmblood jumpers.

BACKGROUND: Cervical osteoarthritis (OA) has been documented as a potential source of pain and poor performance in sport horses. OBJECTIVES: To assess the prevalence of cervical OA in a population of Warmblood jumpers and its correlation with age, level of performance, neck pain and mobility. STUDY DESIGN: Descriptive observational study. METHODS: Warmblood jumpers free of lameness or neurological disorders were selected. Cervical pain and range of motion of the neck were subjectively assessed. Left to right lateral views were taken at C3-C4, C4-C5, C5-C6 and C6-C7. The presence of OA at the cervical articular process joints (APJs) was evaluated and graded as absent, mild or moderate to severe by three board-certified radiologists. The agreement between radiologists and the potential associations between OA grades with age and other variables were statistically assessed (P < .05). RESULTS: One hundred and four horses were included [median age = 10 years (range 6-18 years)]. Agreement between radiologists varied from fair to substantial (Kappa-weighted 0.37-0.61). The C6-C7 APJ was most commonly affected by OA with only 32.7% of APJ considered free of radiographic abnormalities at this location versus 60.5% at C5-C6, 81.7% at C4-C5 and 84.6% at C3-C4. Horses competing in higher level classes (peak of performance) had significantly higher OA grades at C6-C7 (P = .013). There was no association between age, age when started jumping, neck pain and neck range of motion with the presence of OA on radiographs. MAIN LIMITATIONS: Open enrolment and lack of orthogonal views. CONCLUSIONS: This study showed that, although there is a range of interpretation of radiographic findings of the APJ, OA of the caudal cervical region is not rare in performing sound Warmblood jumpers. This suggests that OA in the caudal cervical region may be of low clinical significance.

Do allogeneic bone marrow derived mesenchymal stem cells diminish the inflammatory response to lipopolysaccharide infusion in horses? A pilot study.

Endotoxemia is a leading cause of morbidity and mortality in the equine industry, with colic being the most common cause of endotoxemia in horses. The objective of this study was to evaluate the safety and potential efficacy of a single dose of allogeneic equine bone marrow derived mesenchymal stem cells (BM-MSCs) in horses after the IV administration of lipopolysaccharide (LPS). Six horses were administered an IV infusion of 30 ng/kg LPS (O55:B5 Escherichia coli) in 500 ml saline over 30 min. Immediately after infusion test horses (n = 3) were administered 100 × 106 allogeneic BM-MSCs diluted in saline IV and control horses (n = 3) were administered saline. Clinicopathological data, pro-inflammatory cytokine measurements and sCD14 concentrations were compared between groups. No adverse reactions were observed in horses administered BM-MSCs intravenously. There were no significant differences between test and control horses with regard to clinicopathological values or pro-inflammatory cytokine production. At no time point did concentrations of sCD14 exceed the reference range in any horse. Results suggest that administration of a single IV dose of freshly cultured MSCs is safe and well-tolerated in horses with induced endotoxemia. Further study to evaluate their efficacy as a potential therapeutic in a larger number of horses with clinical disease is required.

Isolation of Campylobacter fetus subspecies fetus from an abdominal abscess in an adult mare.

A 12-year-old Warmblood mare was referred for evaluation of behavioral changes not explained by general physical examination or lameness evaluation. Transrectal ultrasound examination was performed to determine if the behavioral changes were related to ovarian abnormalities, and a large abscess was found near the base of the cecum. Laparoscopic-guided aspiration and lavage of the abscess cavity followed by injection of benzyl penicillin G was carried out. Culture of the lavage sample yielded Campylobacter fetus subspecies fetus, an organism not previously reported as an etiological agent in abdominal abscesses in horses. The mare was treated after surgery with an extended course of antibiotics (minocycline per os q12h for 10 days followed by enrofloxacin per os q24h for 42 days). The mare resumed work in competitive eventing 10 months after surgery, and the behavioral complaints had resolved according to the owner. Key clinical message: We describe the diagnosis and treatment of a mare with an abdominal abscess from which Campylobacter fetus subspecies fetus was cultured. This organism has not previously been reported as an etiological agent in abdominal abscesses in horses.

Isolement de Campylobacter fetus sous-espèce fetus d'un abcès abdominal chez une jument adulte. Une jument Warmblood âgée de 12 ans fut référée pour évaluation de changements de comportement non-expliqués par un examen physique général ou une évaluation de boiterie. Un examen échographique transrectal fut effectué afin de déterminer si les changements de comportement étaient reliées à des anomales ovariennes et un large abcès fut trouvé près de la base du caecum. Une aspiration guidée par laparoscopie et un lavage de la cavité de l'abcès suivis d'une injection de benzyle pénicilline G furent effectués. Une culture de l'échantillon de lavage permis d'identifier Campylobacter fetus sous-espèce fetus, un organisme n'ayant pas été rapporté antérieurement comme agent étiologique dans les abcès abdominaux chez les chevaux. La jument fut traitée après la chirurgie avec un régime prolongé d'antibiotiques (minocycline per os q12h pour 10 jours suivi d'enrofloxacine per os q24h pour 42 jours). La jument recommença à travailler dans des compétitions 10 mois après la chirurgie et les plaintes concernant le comportement étaient résolues selon le propriétaire.Message clinique clé:Nous décrivons le diagnostic et le traitement d'une jument avec un abcès abdominal à partir duquel on isola C. fetus sous-espèce fetus. Cet organisme n'a pas été rapporté antérieurement comme agent étiologique dans les abcès abdominaux chez les chevaux.(Traduit par Dr Serge Messier).

Evaluation of the caudal cervical articular process joints by using a needle arthroscope in standing horses.

OBJECTIVE: To determine the safety and efficacy of caudal cervical articular process joint arthroscopy by using needle arthroscopy in standing sedated horses. STUDY DESIGN: Prospective experimental case series. ANIMALS: Six adult horses. METHODS: Three horses underwent exploration of bilateral C5-6 vertebral articular process joints and three bilateral C6-7 articular process joints by using a 1.2 × 65-mm needle arthroscope under standing sedation. The 16-gauge arthroscopic trocar and canula assembly was inserted in the desired articular process joint under ultrasonographic guidance without distention of the joint. RESULTS: All 12 articular process joints were successfully explored. Entering the joint on the first attempt was achieved in 10 of 12 joints. A craniodorsal approach for arthroscope insertion allowed evaluation of the most cranial aspect of the articular cartilage surface. Triangulation with a spinal needle was determined to be difficult and resulted in a limited space for movement. CONCLUSION: Needle arthroscopy of the caudal cervical facet joints was performed safely and efficiently in standing sedated horses. CLINICAL SIGNIFICANCE: Standing cervical articular process needle arthroscopy is a minimal morbidity technique with the potential to be an advantageous technique for the diagnosis and treatment of cervical articular process pathology.