Use of equine cadaver limb models to enhance veterinary student self-efficacy during arthrocentesis.

OBJECTIVE: To determine if equine cadavers modified with joint distension would yield higher fluid volumes, require fewer needle redirects, and improve student self-efficacy. SAMPLE: 19 third-year veterinary students. METHODS: Voluntary participation was sought during 4 sessions of an equine arthrocentesis and diagnostic analgesia laboratory. Half of the sessions were provided with unmodified cadavers and half were provided with cadavers modified with joint distention. Prior to and after the laboratory, participating students completed surveys regarding their self-efficacy with arthrocentesis of the metacarpophalangeal and distal interphalangeal joints. During the study, the number of needle redirects and the volume of fluid obtained was recorded. RESULTS: Increased fluid volumes were obtained from the modified metacarpophalangeal and distal interphalangeal joints. No difference was identified in number of needle redirects between cadaver types for either joint. Self-efficacy scores increased at the end of the laboratory for arthrocentesis of the metacarpophalangeal joint in both modified and unmodified groups. Self-efficacy scores increased at the end of the laboratory for arthrocentesis of the distal interphalangeal joint for the modified but not unmodified groups. CLINICAL RELEVANCE: Modified equine cadavers provided a higher fluid yield following arthrocentesis compared to unmodified cadavers, but despite this, multiple attempts were required for proper needle placement. Performing equine arthrocentesis improved student self-efficacy with the task. Given our results, the model used for introduction to performing equine arthrocentesis may be less important than practice with the skill. In order to improve proficiency and self-efficacy, equine arthrocentesis should be provided multiple times throughout the veterinary curriculum.

Beta defensins as biomarkers: detectable in LPS-stimulated equine peripheral blood mononuclear cells and normal, aseptic, and probable septic equine synovial fluid.

OBJECTIVES: Diagnosis of equine septic arthritis is not straightforward, and increasing time between onset, diagnosis, and treatment can have serious consequences for quality of life. Defensins are used in diagnosis of human joint infection. The presence of beta defensins (BDs) in equine synovial fluid and their utility as a biomarker of sepsis has not been investigated; therefore, our objectives were to (1) compare in vitro gene expression of lipopolysaccharide (LPS)-stimulated equine neutrophils to unstimulated neutrophils and (2) compare BD protein expression from normal, aseptically inflamed, and septic equine joints. ANIMALS: 5 horses for isolated neutrophil BD expression and 21 synovial fluid samples from 14 horses. PROCEDURES: RT-qPCR analysis was performed for BD gene expression of stimulated and unstimulated equine peripheral neutrophils. BD protein expression was evaluated from equine joints with no disease, aseptic inflammation, and septic inflammation using a commercial ELISA designed for horses and analyzed with a Kruskal-Wallis test (significant at P < .05). RESULTS: A significant increase was noted in expression of BD-3 in LPS stimulated as compared to unstimulated neutrophils. There were no significant differences in BD expression noted between joints with no disease, aseptic inflammation, and septic inflammation. Low case numbers and different types of cases in the aseptic inflammation group were main limitations. BD expression patterns in samples from stimulated equine peripheral neutrophils and synovial fluid were identified. CLINICAL RELEVANCE: BDs are detectable in equine synovial fluid and can be stimulated from peripheral neutrophils. Further examination is needed to define their role as biomarkers of joint disease.

Efficacy of a commercial dry sleeve cryotherapy system for cooling the equine metacarpus.

OBJECTIVE: To determine the ability of a commercial cryotherapy system (Game Ready Equine) to cool the metacarpal subcutaneous tissue and the superficial digital flexor tendon (SDFT) in horses. STUDY DESIGN: Experimental study. ANIMALS OR SAMPLE POPULATION: Six healthy adult horses. METHODS: Thermocouples were implanted into the metacarpal subcutaneous tissues and the SDFT of six horses. Two treatments (cryotherapy or cryotherapy with 5-50 mmHg intermittent compression) were randomly assigned to forelimbs and performed for 20 minutes. Temperatures were compared to the target range of 10-19°C and between groups. RESULTS: Only one limb in the cryotherapy/compression group reached the target range after cryotherapy. Temperatures did not differ between treatment groups at time 0. Lowest temperatures achieved in the subcutaneous tissue (p = .0043) and SDFT (p = .005) were 4.9 and 7.6°C lower when intermittent compression was applied. Similarly, applying compression induced a maximum change in temperature of approximately 7.0°C in the subcutaneous tissue (p = .014) and 10.2°C in the SDFT (p = .0001). CONCLUSION: The cryotherapy system did not cool equine subcutaneous tissue or SDFT to the target temperature range, except in one limb. Combining cryotherapy with intermittent compression did result in lower temperatures and a greater change in temperature of the subcutaneous tissue and SDFT. CLINICAL SIGNIFICANCE: When using this cryotherapy system, the addition of intermittent compression should be considered to achieve lower temperatures and potentially greater reduction in inflammation. Further studies are warranted to determine the effect of longer treatment times, higher compression settings, and the optimal temperature for benefits in normal and diseased equine tissues.

Non-steroidal anti-inflammatory drugs in equine orthopaedics.

Orthopaedic disorders are commonly encountered in equine veterinary medicine, and non-steroidal anti-inflammatory drugs (NSAIDs) play an important role in the management of many equine orthopaedic disorders. There are multiple NSAIDs available for use in horses, including both non-selective and selective NSAIDS, and the body of literature evaluating the efficacy of these medications, their effects on normal and inflamed musculoskeletal tissues, and their side effects is broad. This review aims to summarise the current literature on the use of NSAIDs for equine orthopaedic disorders and examines new and future avenues for the management of inflammation in equine orthopaedics.

Radiographic localization of the attachments of soft tissue structures in the tarsal region of horses.

OBJECTIVE: To identify radiographic locations of soft tissue attachments in the tarsal region of horses and describe any variability in the gross anatomy of those attachments. SAMPLE: 15 cadaveric limbs from 8 adult horses. PROCEDURES: 8 limbs were used for dissection and radiography of soft tissue structures, with metallic markers used to identify radiographic locations of soft tissue attachments. The remaining 7 limbs were used to evaluate anatomic variations in the insertion of the tendon of the fibularis tertius muscle. A consensus list of preferred radiographic views for evaluating each soft tissue attachment was created. RESULTS: The dorsoplantar, dorsoproximolateral-plantarodistomedial oblique (35° proximal and 45° lateral), dorsoproximomedial-plantarodistolateral oblique (10° proximal and 15° medial), and plantaroproximal-plantarodistal oblique (70° proximal; flexed) views were preferred for evaluating the collateral ligaments. The standard oblique views and plantaroproximal-plantarodistal oblique (70° proximal; flexed) view were preferred for evaluating the tendinous attachments of the gastrocnemius and superficial digital flexor muscles. All 4 standard views were necessary for evaluating the tendinous attachments of the cranial tibial and fibularis tertius muscles, the dorsal tarsal ligament, and the origin of the suspensory ligament. Three configurations of the insertion of the fibularis tertius tendon were identified grossly. In limbs with osteoarthritis of the distal tarsal joints, the dorsal tarsal ligament firmly adhered to the centrodistal tarsal joint. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that attachments of soft tissue structures in the tarsal region of horses were in distinct radiographically identifiable locations and that visualization of individual soft tissue attachments could be optimized with certain radiographic views, including some nonstandard views.

Use of perioperative variables to determine the requirement for repeat celiotomy in horses with postoperative reflux after small intestinal surgery.

OBJECTIVE: To determine whether perioperative variables can be used to differentiate a medical vs a surgical reason for postoperative reflux (POR) after small intestinal (SI) surgery in horses. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Horses >1 year of age that recovered from SI surgery and had POR. METHODS: Medical records of horses that underwent SI surgery and developed POR from 2009-2015 were reviewed. Surgical reasons for POR were defined as an anastomosis complication, mechanical obstruction, or nonviable intestine identified at repeat celiotomy/necropsy. A medical reason for POR was presumed when the POR improved with medical treatment or when no surgical reasons were identified at repeat celiotomy/necropsy. Perioperative variables were analyzed and used to develop a logistic regression model. RESULTS: Fifty-one horses had POR after SI surgery. After initial SI surgery, 14 horses had surgical reasons for POR diagnosed at repeat celiotomy or necropsy. Thirty-seven horses were considered to have medical reasons for POR because their POR resolved with medical management or functional ileus was diagnosed at repeat celiotomy/necropsy. A greater volume and a greater duration of POR were not associated with a surgical reason for POR. Rather, a postoperative (PO) fever and the timing of colic in the PO period were associated with a surgical reason for POR. CONCLUSION: Horses that developed a fever and colic in the PO period after SI surgery were more likely to have a surgical reason for POR. CLINICAL SIGNIFICANCE: These findings may provide guidance for clinicians when they are making decisions about repeat celiotomy in horses with POR after SI surgery.

Urethrotomy in combination with or after temporary tube cystostomy for treatment of obstructive urolithiasis in male goats.

OBJECTIVE: To report the clinical findings, outcome, and complications associated with urethrotomy performed in combination with or after temporary tube cystostomy for treatment of obstructive urolithiasis in male goats. STUDY DESIGN: Retrospective case series. SAMPLE POPULATION: Castrated male goats (n = 15). METHODS: The medical records of male goats admitted for obstructive urolithiasis were reviewed. Goats that underwent aurethrotomy performed in combination with or after a temporary tube cystostomy were included in the study population. Follow-up information was obtained through hospital records and telephone communication. RESULTS: Thirteen of 15 goats were discharged from the hospital a median of 13 days (range, 7-25) after urethrotomy. Complications related to the urinary system occurred in 5 goats and included recurrent obstruction, urination from open urethrotomy, uroabdomen and intra-abdominal adhesions after removal of the Foley catheter, and incisional infection. Five of 7 goats with long-term follow-up (2-24 months after surgery) were healthy, with normal urinary function. The remaining 2 goats returned to the hospital with signs of reobstruction that were attributed to uroliths at necropsy in 1 goat. CONCLUSION: Goats treated with urethrotomy for persistent urethral obstruction after temporary tube cystostomy generally survived the procedure. Normal long-term urinary function was obtained in some goats, although recurrence was the most common complication. CLINICAL SIGNIFICANCE: Urethrotomy is a surgical option for male goats with persistent urethral obstruction due to urethral calculi after temporary tube cystostomy.

Use of locking compression plates in ulnar fractures of 18 horses.

OBJECTIVES: To describe the outcome, clinical findings, and complications associated with the use of the locking compression plate (LCP) for various types of ulnar fractures in horses. STUDY DESIGN: Retrospective case series. SAMPLE POPULATION: Client owned horses (n = 18). METHODS: Medical records, radiographs, and follow-up for horses having an ulnar fracture repaired using at least 1 LCP were reviewed. Fifteen of 18 horses had fractures of the ulna only, and 3 horses had fractures of the ulna and proximal radius. RESULTS: All 18 horses were discharged from the hospital. Complications occurred in 5 horses; incisional infection (n = 4, 22%), implant-associated infection (n = 2, 11%), and colic (n = 1, 6%). Follow-up was available for all horses at a range of 13-120 months and 15 horses (83%) were sound for their intended purpose and 3 horses (17%) were euthanatized. One horse was euthanatized for complications associated with original injury and surgery. CONCLUSIONS: The LCP is a viable method of internal fixation for various types of ulnar fractures, with most horses in this series returning to soundness.

Duration of in vivo endotoxin tolerance in horses.

Endotoxemia models are used to study mechanisms and treatments of early sepsis. Repeated endotoxin exposures induce periods of endotoxin tolerance, characterized by diminished proinflammatory responses to lipopolysaccharide (LPS) and modulated production of proinflammatory cytokines. Repeated measure designs using equine endotoxemia models are rarely performed, despite the advantages associated with reduced variability, because the altered responsiveness would confound study results and because the duration of equine endotoxin tolerance is unknown. We determined the interval of endotoxin tolerance, in vivo, in horses based on physical, clinicopathologic, and proinflammatory gene expression responses to repeated endotoxin exposures. Six horses received 30 ng/kg LPS in saline infused over 30 min. Behavior pain scores, physical examination parameters, and blood for complete blood count and proinflammatory gene expression were obtained at predetermined intervals for 24h. Horses received a total of 3 endotoxin exposures. The first exposure was LPS 1, followed 7 days later by LPS 7 or 14-21 days later by LPS 14-21. Lipopolysaccharide exposures were allocated in a randomized, crossover design. Lipopolysaccharide produced clinical and clinicopathologic signs of endotoxemia and increased expression of tumor necrosis factor alpha (TNFα), interleukin (IL)-6 and IL-8, P<0.001. Horses exhibited evidence of endotoxin tolerance following LPS 7 but not following LPS 14-21. Horses had significantly lower pain scores, heart rates, respiratory rates and duration of fever, after LPS 7 compared to LPS 1 and LPS 14-21, P<0.001, and expression of TNFα was lower in the whole blood of horses after LPS 7, P=0.05. Clinical parameters and TNFα gene expression were similar or slightly increased in horses following LPS 14-21 compared to measurements made in horses following LPS 1, suggesting that endotoxin tolerance had subsided. A minimum of 3 weeks between experiments is warranted if repeated measures designs are used to assess in vivo response to endotoxin in horses.