A retrospective study of fecal output and postprocedure colic in 246 horses undergoing standing sedation with detomidine, or general anesthesia with or without detomidine.

OBJECTIVE: To determine time to first passage of feces, total fecal piles and incidence of colic in the first 24 hours postprocedure in horses undergoing standing sedation with detomidine, or general anesthesia with or without detomidine. STUDY DESIGN: Retrospective cohort study. ANIMALS: A total of 246 horses. METHODS: Records of all horses that underwent standing sedation or general anesthesia between December 2012 and March 2016 were reviewed. Horses aged <6 months, admitted for colic or cesarean section, with inadequate data, and those not administered xylazine and/or detomidine were excluded. Records included patient signalment, fasting duration, procedure performed, drugs administered, time to first feces, number of fecal piles during 24 hours postprocedure and mention of colic. Chi-square, Fisher's exact and Tukey's post hoc comparison tests were used. Parametric data were reported as mean ± standard deviation with significance defined as p <0.05. RESULTS: In total, 116 and 57 horses underwent general anesthesia without detomidine (group GA) and with detomidine (group GA-D), respectively, and remaining 73 horses underwent standing sedation with detomidine (group S-D). Detomidine dose was significantly higher in group S-D than in group GA-D. Time to first feces was longer (7.1 ± 4.2 hours), and group S-D horses passed one fewer fecal pile (6.3 ± 2.4) than group GA horses. There was no interaction between detomidine treatment and preprocedure food withholding and the time to first feces or the number of fecal piles in the first 24 hours postprocedure. Overall, seven horses (2.8%) showed signs of colic (five, one and one in GA, GA-D and S-D, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Detomidine administration, as part of an anesthetic protocol or for standing sedation procedures, should not be expected to contribute to postprocedural colic.

Equine Welfare in Practice: A Collaborative Outreach and Education Program with Michigan State University, Universidad Nacional Autónoma de México, and Universidad Veracruzana.

There is great need for veterinary care for working equids worldwide. Addressing this need provides an opportunity for veterinary students to gain primary care experience. An annual two week collaborative outreach and educational program with Michigan State University (MSU), the Universidad Nacional Autónoma de México (UNAM) and the Universidad Veracruzana (UV) was developed to provide care for working equids in rural Mexican communities. From 2017 to 2019 24 US veterinary students and 25 Mexican veterinary students, interns and residents examined, vaccinated and dewormed more than 2200 equids and performed more than 80 castrations, 100 rectal palpations for pregnancy diagnosis, 220 dental floats and 320 hoof trims. They also treated many wounds, sarcoids, vampire bat bites and tick infestations and also saw unusual cases including tetanus, eye injuries, nuchal bursitis, cervical vertebral malformation and suspected vesicular stomatitis. Development of the collaborative MSU-UNAM-UV Equine Welfare in Practice Clerkship required vision, learning, relationship building, creativity, fund-raising and perseverance to develop and agree on mutually beneficial objectives for all participants. The project is largely financed through private donations and supplies provided by pharmaceutical companies. The outcome has been a highly successful program that could be used as a model by other Colleges of Veterinary Medicine world-wide.

Expression of pro-apoptotic markers is increased along the osteochondral junction in naturally occurring osteochondrosis.

Osteochondrosis (OC) is a naturally occurring disease of the articular-epiphyseal cartilage and subchondral bone layers, leading to pain and decreased mobility. The objective of this study was to characterize gene and protein expression of apoptotic markers in chondrocytes surrounding cartilage canals and along the osteochondral junction of osteochondrosis (OC)-affected and normal cartilage, using naturally occurring disease in horses. Paraffin-embedded osteochondral samples (6 OC, 8 normal controls) and cDNA from chondrocytes captured with laser capture microdissection (4 OC, 6 normal controls) were obtained from the lateral trochlear ridge of femoropatellar joints in 14 immature horses (1-6 months of age). Equine-specific caspase-3, caspase-8, caspase-10, Fas, Bcl-2, BAG-1, TNFα, cytochrome C, thymosin-ß10, and 18S mRNA expression levels were evaluated by two-step real-time quantitative PCR. Percentage of cell death was determined using the TUNEL method. Protein expression of caspase-10, Fas, cytochrome C, and thymosin-ß10 was determined following immunohistochemistry. Statistical analysis was performed using the Wilcoxon rank sum test or two-sample t-test (p < 0.05). In OC samples, there was significantly increased gene expression of caspase-10, Fas, cytochrome C, and thymosin-ß10 in chondrocytes along the osteochondral junction and increased Fas gene expression in chondrocytes adjacent to cartilage canals, compared to controls. In OC samples, higher matrix Fas and cytochrome C protein expression, lower mitochondrial cytochrome C protein expression, and a trend for higher cytoplasmic caspase-10 protein expression were found. Collectively, these results suggest that both extrinsic and intrinsic apoptotic pathways are activated in OC cartilage. Increased apoptosis of osteochondral junction chondrocytes may play a role in OC, based on increased gene expression of several pro-apoptotic markers in this location.

Development of a minimally invasive approach to equine cervical articular facet joints for placement of an ND:YAG LASER.

The purpose of this study was to develop a minimally invasive approach to equine cervical articular facet joints for application of an ND:YAG LASER and to evaluate the effects of the laser fiber on the surrounding tissue. Under general anesthesia, an ND:YAG LASER was used to apply 2000 J of energy to 5 cervical articular facet joints in 3 horses (15 joints total). Horses were euthanized and the cervical facets and spinal cords were examined grossly and histologically. Gross pathology of the articular facets revealed evidence of articular cartilage charring and diffuse roughening of the surface. Histopathology confirmed coagulative necrosis. This novel technique allowed access to the cervical articular facet joints with the ND:YAG LASER and has the potential to allow performance of a minimally invasive facilitated ankylosis procedure. Further validation in sedated, standing horses is required to establish safety and efficacy of this technique.

Développement d'une approche minimalement invasive pour les facettes vertébrales lombaires équines pour le placement d'un LASER ND:YAG. Le but de cette étude était de développer une approche minimalement invasive pour l'application d'un LASER ND:YAG sur les facettes vertébrales lombaires équines et l'évaluation des effets de la fibre laser sur les tissus environnants. Sous anesthésie générale, un LASER ND:YAG a été utilisé pour appliquer 2000 J d'énergie à 5 facettes vertébrales lombaires chez 3 chevaux (total de 15 articulations). Les chevaux ont été euthanasiés et les facettes vertébrales et les colonnes vertébrales ont été examinées macroscopiquement et histologiquement. La pathologie macroscopique des facettes vertébrales lombaires a révélé des preuves de carbonisation du cartilage dens articulaires et un durcissement diffus de la surface. L'histopathologie a confirmé la nécrose decoagulatio. Cette technique nouvelle a permis l'accès aux facettes vertébrales lombaires avec le LASER ND:YAG et a le potentiel de permettre la réalisation d'interventions d'ankylose minimalement invasives. De nouvelles études de validation chez des chevaux debout sous sédation sont requises pour établir l'innocuité et l'efficacité de cette technique.(Traduit par Isabelle Vallières).

Correlation of dickkopf-1 concentrations in plasma and synovial fluid to the severity of radiographic signs of equine osteoarthritis.

OBJECTIVE: The purpose of this study was to determine whether there was a correlation between circulating and intra-synovial Dkk-1 and radiographic signs of equine osteoarthritis. METHODS: Circulating and intra-synovial Dkk-1 levels were measured in clinical cases using a commercially available human Dkk-1 ELISA. Radiographs were performed of the joints from which fluid was collected and these were assessed and scored by a boarded radiologist for joint narrowing, subchondral bone sclerosis, subchondral bone lysis, and periarticular modelling. Comparisons were made between radiographic scores and the concentrations of Dkk-1 using a Kruskal-Wallis one-way ANOVA. Correlations were calculated using Kendall's statistic. RESULTS: A total of 42 synovial fluid samples from 21 horses were collected and used in the analysis. No significant correlation was identified between Dkk-1 concentrations and radiographic signs of osteoarthritis. Intra-synovial Dkk-1 concentrations were significantly greater (p <0.001) in low motion joints (mean concentration, 232.68 pg/mL; range, 109.07-317.17) when compared to high-motion joints (28.78 pg/mL; 0.05-186.44 pg/mL) (p <0.001). CLINICAL SIGNIFICANCE: Low motion joints have significantly higher concentrations of Dkk-1 compared to high motion joints. Further research is needed to establish the importance of this finding and whether potential diagnostic or therapeutic applications of Dkk-1 exist in the horse.

Wnt/ß-catenin signaling of cartilage canal and osteochondral junction chondrocytes and full thickness cartilage in early equine osteochondrosis.

The objective of this study was to elucidate gene and protein expression of Wnt signaling molecules in chondrocytes of foals having early osteochondrosis (OC) versus normal controls. The hypothesis was that increased expression of components of Wnt signaling pathway in osteochondral junction (OCJ) and cartilage canal (CC) chondrocytes would be found in early OC when compared to controls. Paraffin-embedded osteochondral samples (7 OC, 8 normal) and cDNA from whole cartilage (7 OC, 10 normal) and chondrocytes surrounding cartilage canals and osteochondral junctions captured with laser capture microdissection (4 OC, 6 normal) were obtained from femoropatellar joints of 17 immature horses. Equine-specific Wnt signaling molecule mRNA expression levels were evaluated by two-step real-time qPCR. Spatial tissue protein expression of ß-catenin, Wnt-11, Wnt-4, and Dkk-1 was determined by immunohistochemistry. There was significantly decreased Wnt-11 and increased ß-catenin, Wnt-5b, Dkk-1, Lrp6, Wif-1, Axin1, and SC-PEP gene expression in early OC cartilage canal chondrocytes compared to controls. There was also significantly increased ß-catenin gene expression in early OC osteochondral junction chondrocytes compared to controls. Based on this study, abundant gene expression differences in OC chondrocytes surrounding cartilage canals suggest pathways associated with catabolism and inhibition of chondrocyte maturation are targeted in early OC pathogenesis.

Analgesic and gastrointestinal effects of epidural morphine in horses after laparoscopic cryptorchidectomy under general anesthesia.

OBJECTIVE: To evaluate the hypothesis that epidural morphine (0.1 mg kg(-1) ) decreases pain in horses after laparoscopic surgery without adversely affecting gastrointestinal (GI) motility. STUDY DESIGN: Randomized clinical trial. ANIMALS: Eighteen horses undergoing laparoscopic cryptorchidectomy under general anesthesia. METHODS: Horses were randomly assigned to receive either epidural morphine (0.1 mg kg(-1) ) or no epidural before the start of surgery. Pain behaviors were assessed during the first two post-operative days using a numerical rating scale. Barium-filled spheres were administered through a nasogastric tube before anesthesia. GI motility was assessed by recording manure production, by quantitating the spheres in the manure, and by abdominal auscultation of intestinal sounds. Heart rates and cortisol concentrations were also measured during the post-operative period. RESULTS: Pain scores increased for 12 hours after surgery in the control group and were significantly higher than in the morphine group for the first 6 hours. Pain scores remained unaltered in the morphine group throughout the observation period. Heart rate and plasma cortisol concentrations did not differ between groups or with time. No signs of colic were observed in any horse. CONCLUSION AND CLINICAL RELEVANCE: Epidural morphine (0.1 mg kg(-1) ) did not adversely affect GI motility in horses after laparoscopic surgery under general anesthesia.

Use of plain radiography in the diagnosis, surgical management, and postoperative treatment of obstructive urolithiasis in 25 goats and 2 sheep.

OBJECTIVE: To describe use of plain radiography for diagnosis, surgical management, and postoperative treatment of obstructive urolithiasis in small ruminants. STUDY DESIGN: Retrospective case series. ANIMALS: Small ruminants (n = 27; 25 goats, 2 sheep). METHODS: Medical records (January 2002-November 2011) and radiographs for all small ruminants diagnosed with obstructive urolithiasis and having plain abdominal radiographs were reviewed. Signalment, surgical procedures, radiographic findings, ultrasonographic findings, position of calculi, and how plain radiography influenced surgical management and postoperative treatment were recorded. RESULTS: Radiopaque urinary calculi were detected in 23 (85%) plain radiographic studies. Location of uroliths determined by plain radiography included: cystic only (n = 5), distal to the sigmoid flexure and cystic (5), subischial (5), distal to the sigmoid flexure only (3), sigmoid flexure (3), and subischial and cystic (2). In 8 of these animals, postoperative radiographs revealed residual calculi in the urethra and were essential for their targeted removal by urethrotomy in 7 animals. CONCLUSIONS: In regions where radiopaque calculi (calcium carbonate, calcium oxalate, silica) are commonly encountered in small ruminants, plain radiographs are recommended to determine the appropriate surgical approach(es) and to confirm resolution of the obstruction.