Search

Ethanol, a central nervous system depressant and banned substance in horseracing, has reportedly been administered to horses prior to competition to "calm a horse's nerves." In this study, the pharmacokinetics of two metabolites of ethanol were studied to better understand the behavior of this compound in the horse and provide a scientific basis for regulation of its administration. Six horses received a single intravenous (30 mL; 1200 mg) and oral (90 mL; 3600 mg) administration of ethanol (vodka, 40% ABV) in a balanced cross-over design. Blood and urine samples were collected at various times post administration for up to 24 h. Concentrations of ethyl glucuronide and ethyl sulfate were determined using liquid chromatography-tandem mass spectrometry and pharmacokinetic analysis performed. Behavioral, locomotor activity and effects on heart rate were assessed. The maximum concentration (mean ± SD) of ethyl glucuronide was 71.5 ± 42.7 and 105.0 ± 47.5 ng/mL at 0.88 h following IV and oral administration, respectively. The maximum concentrations for the ethyl sulfate metabolite following IV and oral administration were 1.61 ± 0.60 and 3.46 ± 1.68 ng/mL, respectively. Urine concentrations of both metabolites were non-detectable by 24 h post ethyl alcohol administration. No observable behavioral responses were noted following IV or oral administration. Significant decreases in heart rate were noted at various times starting at 10 min until 4 h post administration in the oral dose group. Both ethyl glucuronide and ethyl sulfate could be useful markers for detection of illicit administration of ethanol to horses., (© 2024 The Author(s). Drug Testing and Analysis published by John Wiley & Sons Ltd.)

Objective: To investigate the impact of surgery resident training on surgery duration in tibial plateau leveling osteotomy (TPLO) and evaluate whether surgery duration differs with each year of residency training., Study Design: Retrospective medical record review., Animals: A total of 256 client-owned dogs underwent TPLO., Methods: Records of dogs that underwent TPLO between August 2019 and August 2022 were reviewed. The effects of the surgeon (faculty/resident) and the procedure (arthrotomy/arthroscopy) on TPLO surgery duration were examined with an analysis of variance, and geometric least squares means (GLSM) were compared. A linear mixed effects model (LMM) was fitted to quantify fixed and random effects., Results: Four faculty surgeons performed 74 (29%) TPLOs, while 10 residents performed 182 (71%) TPLOs under the direct supervision of a faculty surgeon. All TPLOs were conducted with arthrotomy (109; 43%) or arthroscopy (147; 57%). Overall, residents (GLSM, 153 min) required 54% more surgery duration than faculty surgeons (GLSM, 99 min). Surgery duration among first-year residents (GLSM, 170 min) was 15% longer than second- (GLSM, 148 min) and third-year (GLSM, 147 min) residents, whereas the duration did not differ statistically between second- and third-year residents. Arthroscopy, meniscal tear treatment, surgery on the right stifle, and increasing patient weight were also associated with longer surgery duration., Conclusion: The duration of TPLO surgery significantly decreased after the first year of residency, but did not decrease afterward., Clinical Significance: The results will aid with resource allocation, curricula planning, and cost management associated with resident training., (© 2024 The Authors. Veterinary Surgery published by Wiley Periodicals LLC on behalf of American College of Veterinary Surgeons.)

Ketoprofen is an anti-inflammatory drug that is commonly administered to racehorses for the alleviation of musculoskeletal pain and inflammation. This study represents a comprehensive examination of the metabolism (in vivo and in vitro), pharmacokinetics and ex vivo pharmacodynamics, of ketoprofen in horses. The in vitro metabolism as well as specific enzymes responsible for metabolism was determined by incubating liver microsomes and recombinant CYP450 and UGT enzymes with ketoprofen. For the in vivo portion, 15 horses were administered a single intravenous dose of 2.2-mg/kg ketoprofen. Blood and urine samples were collected prior to and up to 120 h post-drug administration. Additional blood samples were collected at select time points and were stimulated with calcium ionophore or lipopolysaccharide, ex vivo, to induce eicosanoid production. Drug, metabolite, and eicosanoid concentrations were determined using LC-MS/MS. Incubation of ketoprofen with equine liver microsomes generated 3-hydroxy ketoprofen, an unidentified hydroxylated metabolite, and ketoprofen glucuronide. Recombinant equine CYP2C23 produced the greatest amount of hydroxylated ketoprofen and recombinant equine UGT1A2 generated ketoprofen glucuronide. Dihydro, 3-hydroxy, and glucuronide metabolites were identified in blood and urine samples. The Vd ss was 0.280, 0.385, and 0.319 L/kg for total ketoprofen, S (+) ketoprofen, and R (-) ketoprofen, respectively. The mean half-life was 6.01 h for total ketoprofen, 2.22 h for S (+) ketoprofen, and 1.72 h for R (-) ketoprofen. Stimulation of ketoprofen-treated blood with lipopolysaccharide and calcium ionophore resulted in an inhibition of TXB 2 , PGE 2 , PGF 2alpha , LTB 4 , and 15(s)-HETE production for up to 120 h post-drug administration., (© 2023 John Wiley & Sons Ltd.)

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., (© 2021 American College of Veterinary Surgeons.)

The increasing availability of cannabidiol (CBD) and anecdotal reports of its anti-inflammatory effects has garnered it much interest in the equine industry. The objectives of the current study were to (1) describe the pharmacokinetics of oral CBD in exercising thoroughbreds, (2) characterize select behavioral and physiologic effects, and (3) evaluate effects on biomarkers of inflammation using an ex vivo model. This study was conducted in a randomized balanced 3-way crossover design with a two-week washout period between doses. Horses received a single oral dose (0.5, 1, and 2 mg/kg) of CBD suspended in sesame oil. Blood and urine samples were collected prior to and for 72 hr post drug administration. Additional blood samples collected at select time points were challenged ex vivo with calcium ionophore or lipopolysaccharide to induce eicosanoid production. Drug, metabolite, and eicosanoid concentrations were determined using LC-MS/MS. Cannabidiol was well tolerated with no significant behavioral, gastrointestinal, or cardiac abnormalities observed. CBD was readily absorbed, with parent drug detected in blood at all time points. The carboxylated and hydroxylated metabolites predominated in serum and urine, respectively. The terminal half-life for CBD was 10.7 ± 3.61, 10.6 ± 3.84 and 9.88 ± 3.53 for 0.5, 1, and 2 mg/kg. Although the effects were mixed, results of eicosanoid analysis suggest CBD affects COX-1, COX-2 and LOX at the doses studied here. Results of this study coupled with previous reports in other species, suggest further study of CBD in horses is warranted before its use as an anti-inflammatory can be recommended., (© 2021 John Wiley & Sons, Ltd.)

Objective: To predict readiness for laparoscopic ovariectomy of live dogs on the basis of performance on a high-fidelity laparoscopic abdominal simulator and to determine interrater reliability of the assessment., Study Design: Experimental study., Sample Population: Seventeen fourth-year veterinary students., Methods: After a standardized laparoscopic training course, each participant performed a laparoscopic ovariectomy with a simulator. This performance was scored in real time by two evaluators using a rubric. Participants achieving a score of 112 of 160 performed a laparoscopic ovariectomy in a live dog, supervised by an instructor in the room. Two evaluators scored video recordings of each procedure using the rubric. Participants' opinions about the simulator were collected with a survey., Results: All participants scored above the threshold (range, 126-151) and successfully completed laparoscopic ovariectomy in a live dog, with an average of 10 of 17 participants requiring verbal guidance and 5 of 17 participants requiring intervention from the instructor. Interrater concordance was excellent for the rubrics used to score performance on the simulator (R = 0.91) and in vivo (R = 0.81). All participants agreed that the simulator should be used to assess trainee readiness prior to surgery in a live dog., Conclusion: Participants achieving a score of at least 126 of 160 on the simulator were able to perform a laparoscopic ovariectomy in a live dog under supervision. The scoring system for the simulator had excellent interrater concordance., Clinical Significance: This simulator and scoring system can be used in laparoscopic training programs to assess readiness for progression to the operative setting., (© 2021 The American College of Veterinary Surgeons.)

Corticosteroids are potent anti-inflammatory drugs and as such are commonly administered to performance and racehorses. The objectives of the current study were to describe blood and urine concentrations and the pharmacokinetics and effects on cortisol and inflammatory mediator concentrations, following intravenous and oral administration to 12 exercised horses. Horses received an intravenous administration of 40 mg of dexamethasone sodium phosphate and 20 mg of dexamethasone tablets with a 4 week washout in between administrations. Blood and urine samples were collected prior to and for up to 96 hours post drug administration. Whole blood samples were collected at various time points and challenged with lipopolysaccharide or calcium ionophore to induce ex vivo synthesis of eicosanoids. The concentrations of dexamethasone and eicosanoids were measured using LC-MS/MS and the concentrations from both routes of administration fit simultaneously using a three-compartment pharmacokinetic model. A turnover model with inhibition of K in gave an adequate fit to the dexamethasone-cortisol PKPD data. Serum and urine dexamethasone concentrations were at the limit of quantitation at 96 and 48 hours post administration, respectively. The volume of distribution, systemic clearance, and terminal half-life was 0.907 L/kg, 7.89 mL/h/kg, and 1.34 h, respectively. The IC 50 for cortisol suppression was 0.007 ng/mL. Stimulation of dexamethasone treated blood with lipopolysaccharide and calcium ionophore resulted in an inhibition of inflammatory biomarker production for a prolonged period of time post drug administration. The results of this study suggest that dexamethasone has a prolonged anti-inflammatory effect following intravenous or oral administration to horses., (© 2020 John Wiley & Sons, Ltd.)

Methamphetamine is a central and peripheral nervous system stimulant. There is only a single study that describes exposure to and disposition of this compound in horses. The potential for abuse and inadvertent exposure in equine athletes along with the limited data available necessitates further study. The objectives of the current study were to describe drug and metabolite concentrations, develop an analytical method that could be used to regulate its use, and describe selected pharmacodynamic effects. In phase 1, six horses were randomized into three transmucosal dose groups (n = 2/group; 0.5, 1.0 or 10 mg). In phase 2, horses received a single 10 mg intravenous dose. In phase 3, the effects of urinary pH on elimination were studied. Blood and urine samples were collected for up to 72 hours post drug administration. Concentrations of methamphetamine were measured using liquid chromatography-tandem mass spectrometry. Methamphetamine was below the limit of detection (LOD) in blood by 2, 4, and 18 hours following transmucosal administration of 0.5, 1, and 10 mg, respectively. Following intravenous administration, methamphetamine fell below the LOD between 12 and 18 hours. Following urinary acidification, methamphetamine fell below the limit of quantitation (LOQ) by 12 hours. In urine, methamphetamine was no longer detected at 48, 48, and 72 hours in the 0.5, 1, and 10 mg transmucosal groups and 18 hours in the intravenous group. Increased urinary pH resulted in urinary concentrations of methamphetamine falling below detectable levels by 48 hours post transmucosal administration. While the number of animals was small, behavioral, stimulatory, and cardiac effects were minimal., (© 2019 John Wiley & Sons, Ltd.)

Phenylbutazone (PBZ) is a potent mon-steroidal anti-inflammatory drug used commonly in performance horses. The objectives of the current study were to describe blood and urine concentrations and the pharmacokinetics of PBZ and its metabolites following intravenous (IV) and oral administration and to describe the duration of pharmacodynamic effect. To that end, 17 horses received an IV administration and 18 horses an oral administration of 2 g of PBZ. Blood and urine samples were collected prior to and for up to 96 hours post drug administration. Whole blood samples were collected at various time points and challenged with lipopolysaccharide or calcium ionophore to induce ex vivo synthesis of eicosanoids. Concentrations of PBZ and eicosanoids were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and non-compartmental pharmacokinetic analysis performed on concentration data from IV and oral administration. Serum concentrations of PBZ and its metabolites were below the limit of quantitation at 96 hours post administration. The volume of distribution at steady state, systemic clearance, and terminal half-life was 0.194 ± 0.019 L/kg, 23.9 ± 4.48 mL/h/kg, and 10.9 ± 5.32 hours, respectively. The terminal half-life following oral administration was 13.4 ± 3.01 (paste) and 15.1 ± 3.96 hours (tablets). Stimulation of PBZ treated whole blood with lipopolysaccharide and calcium ionophore resulted in an inhibition of TXB 2 , PGE 2 , LTB 4 and 15-HETE production for a prolonged period of time post drug administration. The results of this study suggest that PBZ has a prolonged anti-inflammatory following IV or oral administration of 2 g to horses., (© 2018 John Wiley & Sons, Ltd.)

Objective: To evaluate response to surgical management of sliding hiatal hernia (SHH) and gastroesophageal reflux (GER) in dogs using standardized clinical scoring, videofluoroscopic swallow studies, and impedance planimetry., Study Design: Prospective clinical trial., Animals: A total of 17 client-owned dogs., Methods: Dogs were included if they had clinical signs and videofluoroscopic evidence of SHH and/or GER. Owners were asked to complete a standardized canine dysphagia assessment tool (CDAT) preoperatively and postoperatively. Conscious videofluoroscopic swallowing studies and impedance planimetry (IP) were used to evaluate esophageal function and lower esophageal sphincter location and geometry preoperatively and in a subsection of dogs postoperatively., Results: Preoperatively, 13/17 dogs included in the study had a history of regurgitation, and 4/17 had radiographic evidence of aspiration pneumonia. Postprandial regurgitation improved in 8/10 dogs with preoperative regurgitation, and for which completed preoperative and postoperative CDAT questionnaires were available (P < .01). The hiatal hernia severity score improved postoperatively (P = .046) in dogs with preoperative and postoperative videofluoroscopic swallowing studies (n = 12). However, hernia frequency score (P = .2) and IP parameters did not differ significantly between time points., Conclusion: Clinical signs of SHH generally improved with surgery but did not consistently resolve. Videofluoroscopic studies provide evidence that GER and SHH can persist postoperatively in some patients. Based on IP findings, clinical improvement may be attributed to a mechanism independent of lower esophageal sphincter attenuation., (© 2017 The American College of Veterinary Surgeons.)

Although developed as a therapeutic medication, meldonium has found widespread use in human sports and was recently added to the World Anti-Doping Agency's list of prohibited substances. Its reported abuse potential in human sports has led to concern by regulatory authorities about the possible misuse of meldonium in equine athletics. The potential abuse in equine athletes along with the limited data available regarding the pharmacokinetics and pharmacodynamics of meldonium in horses necessitates further study. Eight exercised adult thoroughbred horses received a single oral dose of 3.5, 7.1, 14.3 or 21.4 mg/kg of meldonium. Blood and urine samples were collected and analyzed using liquid chromatography tandem mass spectrometry. Pharmacokinetic parameters were determined using non-compartmental analysis. Maximum serum concentrations ranged from 440.2 to 1147 ng/mL and the elimination half-life from 422 to 647.8 h. Serum concentrations were below the limit of quantitation by days 4, 7, 12 and 12 for doses of 3.5, 7.1, 14.3 and 21.4 mg/kg, respectively. Urine concentrations were below the limit of detection by day 44 following administration of 3.5 mg/kg and day 51 for all other dose groups. No adverse effects were observed following meldonium administration. While the group numbers were small, changes in heart rate were observed in the 3.5 mg/kg dose group (n = 1). Glucose concentrations changed significantly in all dose groups studied (n = 2 per dose group). Similar to that reported for humans, the detection time of meldonium in biological samples collected from horses is prolonged, which should allow for satisfactory regulation in performance horses. Copyright © 2017 John Wiley & Sons, Ltd., (Copyright © 2017 John Wiley & Sons, Ltd.)

Objective: To determine outcome and prognostic factors after radius and ulna fracture repair with a modified IMEX miniature circular external skeletal fixation (MCESF) in small and toy breed dogs., Study Design: Retrospective study., Sample Population: Thirty-seven young small and toy breed dogs with 41 radial and ulnar fractures., Methods: Records of radial and ulnar fractures repaired with a modified IMEX MCESF were reviewed. Constructs included 3-4 complete rings, 2 threaded rods, 4 mm-diameter nuts and 6-8 transfixation wires. MCESF configuration, type of fracture reduction, dynamization of the apparatus, inclusion of a dowel pin, and implantation of allograft were recorded. Outcome measures included complications, limb alignment, time to clinical union, and functional outcomes, scored as excellent, good, fair, or poor., Results: Radiographic union was achieved in 40/41 fractures. Fractures reached bony union within 33-84 days after repair. Time to union was not influenced by the type of fracture reduction (P = .11), use of a dowel pin (P = .099), or implantation of an allograft (P = .45). Fracture dynamization delayed radiographic union (P = .0005). At implant removal, mean frontal (FPA) and mean sagittal plane alignments (SPA) were 7.9° ± 6.5° and 7.5° ± 5.8°, respectively. Limb alignment did not differ between radiographs obtained immediately after surgery and those obtained at time of radiographic union in the frontal (P = .062) or sagittal (P = .14) planes. Ninety-five percent of cases had good-to-excellent outcomes, based on return to function at final re-evaluations., Conclusion: This modified IMEX MCESF construct provided an effective alternative to treat young small and toy breed dogs with radius and ulna fractures., (© 2017 The American College of Veterinary Surgeons.)

There is limited data describing xylazine serum concentrations in the horse and no reports of concentrations beyond 24 hours. The primary goal of the study reported here was to update the pharmacokinetics of xylazine following intravenous (IV) administration in order to assess the applicability of current regulatory recommendations. Pharmacodynamic parameters were determined using PK-PD modeling. Sixteen exercised adult Thoroughbred horses received a single IV dose of 200 mg of xylazine. Blood and urine samples were collected at time 0 and at various times for up to 96 hours and analyzed using liquid chromatography tandem mass spectrometry. Xylazine serum concentrations were best fit by a 3-compartment model. Mean ± SEM systemic clearance, volume of distribution at steady state, beta half-life and gamma half-life were 12.7 ± 0.735 mL/min/kg, 0.660 ± 0.053 L/kg, 2.79 ± 0.105 hours and 26.0 ± 1.9, respectively. Immediately following administration, horses appeared sedate as noted by a decrease in chin-to-ground distance, decreased locomotion and decreased heart rate (HR). Sedation lasted approximately 45 minutes. Glucose concentrations were elevated for 1-hour post administration. The EC50 (IC50) was 636.1, 702.2, 314.1 and 325.7 ng/mL for HR, atrioventricular block, chin-to-ground distance and glucose concentrations, respectively. The Emax (Imax) was 27.3 beats per minute, 47.5%, 42.4 cm and 0.28 mg/dL for HR, atrioventricular block, chin-to-ground distance and glucose concentrations, respectively. Pharmacokinetic parameters differ from previous reports and a prolonged detection time suggests that an extended withdrawal time, beyond current regulatory recommendations, is warranted to avoid inadvertent positive regulatory findings in performance horses. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

Objective: To determine if preoperative and intraoperative physiologic variables, and surgical factors correlate with survival to anesthetic recovery or hospital discharge, repeat celiotomy, and postoperative nasogastric intubation (NGT) in horses undergoing exploratory celiotomy for small intestinal (SI) strangulating lesions., Study Design: Retrospective case series., Animals: Horses that had surgical correction of SI strangulating lesions (n = 258)., Methods: Medical records (January 2000-December 2014) of horses that had surgical correction of SI strangulating lesions were reviewed. Data collection included signalment, preoperative physical examination variables, hematologic values, presence of gastric reflux, peritoneal fluid analysis, intraoperative physiologic variables, intraoperative findings/treatments, and arterial blood gas values. Risk factors for survival to anesthetic recovery and hospital discharge were determined using exact logistic regression., Results: Survival to anesthetic recovery was 76% and survival to discharge after anesthetic recovery was 79%. The difference between abdominal and peripheral lactate concentrations and intraoperative tachycardia were associated with not surviving to anesthetic recovery or hospital discharge. Intraoperative hypotension, hypocapnia, and low intraoperative packed cell volume (PCV) were negative predictors of survival to anesthetic recovery. Low intraoperative PCV was also associated with NGT postoperatively. Performing resection-anastomosis and jejunocecostomy were associated with repeat celiotomy and with not surviving to hospital discharge., Conclusion: Several hematological and cardiorespiratory variables show good correlation with short-term survival in horses undergoing surgery for SI strangulating lesions. These variables are easily measured and could be useful for prognosticating survival in horses presenting with SI strangulating lesions., (© 2017 The American College of Veterinary Surgeons.)

Objective: To describe indications for, and outcomes after, pneumonectomy in dogs and cats, including assessment of immediate postoperative respiratory function in comparison to dogs undergoing single lung lobectomy., Study Design: Retrospective case series., Animals: Dogs (n=16) and cats (n=7) with naturally occurring pulmonary disease., Methods: Medical records (1990-2014) of dogs and cats undergoing right or left pneumonectomy were reviewed. Data retrieved included signalment, history, preoperative diagnostics, operative descriptions, postoperative data including respiratory function, and postdischarge outcomes. For respiratory function comparisons, medical records of dogs having undergone a single lung lobectomy via median sternotomy (n=15) or intercostal thoracotomy (n=15) were reviewed., Results: Twenty-three cases (16 dogs, 7 cats) were included. Pneumonectomy was performed for congenital (1 dog, 1 cat), neoplastic (8 dogs, 1 cat), and infectious (7 dogs, 5 cats) disease. Postoperative aspiration pneumonia occurred in 2 dogs; 15 of 16 dogs (94%) and 6/7 cats (86%) survived to hospital discharge. After pneumonectomy, dogs had a significantly higher postoperative PaO2 on 21% oxygen (P=.033) and lower postoperative A-a gradient (P=.004) compared to dogs undergoing single lung lobectomy. Survival times (right-censored at last follow-up) for dogs ranged from 2 days to 7 years (estimated median=1,868 days) and for cats from 1-585 days., Conclusion: Dogs and cats have acceptable respiratory function immediately postoperatively and most have protracted long-term survival after pneumonectomy for a variety of pulmonary diseases., (© Copyright 2016 by The American College of Veterinary Surgeons.)

Objective: To describe a novel percutaneous radiologic gastropexy (PRG) technique in a canine model and to biomechanically compare this technique to open incisional gastropexy (OIG) and laparoscopic-assisted incisional gastropexy (LAG)., Study Design: Randomized ex vivo biomechanical study., Animals: Canine cadavers., Methods: Fifteen cadavers were randomized to 1 of 3 surgical interventions: OIG, LAG, and PRG. For the PRG procedure, the stomach was distended with air, and a preloaded T-fastener device was utilized to attach the stomach to the body wall with fluoroscopic-guidance. The procedural times of the 3 techniques were recorded. After completion of the procedure, the stomach and body wall overlying the stomach wall were harvested and the maximum tensile strength of the gastropexies was determined., Results: The maximal tensile strength was not significantly different between groups. The total procedural time for the PRG procedure (5 minutes) was significantly shorter than both OIG (28 minutes) and LAG (20 minutes) procedures., Conclusion: The PRG technique described in this study demonstrated a similar maximal tensile strength to commonly employed gastropexy techniques (OIG and LAG) in an acute canine model. Additionally, the PRG procedure was significantly faster to perform. The clinical relevance of this technique will be determined by further study to assess the applicability and efficacy of this procedure in clinical patients by determining the likelihood of adhesion development and the ability of the adhesion to prevent gastric volvulus., (© Copyright 2016 by The American College of Veterinary Surgeons.)

Objectives: To document a technique for one-lung ventilation (OLV) in cats and evaluate the effect of low-pressure carbon dioxide insufflation and OLV (OLV-CDI) on cardiorespiratory variables in cats., Study Design: Prospective randomized study., Animals: Cats (n = 6)., Methods: General anesthesia was induced using a standardized anesthetic protocol. A thermodilution catheter was placed into the pulmonary artery using fluoroscopic guidance. Two 6 mm thoracoscopic cannulae were placed at a subxiphoid and intercostal location, respectively, to allow direct observation of all lung lobes. OLV was induced using an endobronchial blocker, which was placed into the right and left main stem bronchi in randomized order using bronchoscopic guidance. Cardiorespiratory variables were measured at 5 and 30 minutes after induction of OLV and subsequently at 5 and 30 minutes after initiation of OLV-CDI at intra-thoracic pressures of 3 mmHg., Results: Left-sided OLV was successful in 5 cats, right-sided OLV was successful in 2 cats, and neither was successful in 1 cat. No significant effects on hemodynamic variables or oxygen delivery were observed after right or left-sided OLV alone. Hemodynamic variables were also well-preserved after OLV-CDI; however, oxygen delivery was significantly lower after left OLV-CDI compared with right OLV-CDI, and in 2 cats, severe desaturation occurred after L-OLV-CDI before the 30 minute time point., Conclusions: OLV can be used in cats for thoracoscopic interventions. Although right OLV-CDI was tolerated better than left OLV-CDI, the technique requires further investigation before it can be recommended for widespread clinical use., (© Copyright 2014 by The American College of Veterinary Surgeons.)

Objective: To determine if application of silver sodium zirconium phosphate polyurethane semi-occlusive foam (SPF) dressing would improve measures of wound healing and decrease bacterial contamination compared with a non-adherent, absorbent dressing applied to wounds created on the distal aspect of the equine limb., Study Design: Controlled randomized experimental study., Animals: Adult Quarter Horse and Thoroughbred horses (n = 5)., Methods: One 6.25 cm(2) wound was created on the dorsomedial aspect of the proximal metacarpus on each forelimb. A SPF dressing was applied to 1 randomly assigned limb as a treatment and a non-adherent, absorbent dressing was applied to the opposite limb as control. Bandages were changed every 3 days for 60 days. Granulation tissue was scored every 3 days, wound area measured every 6 days, and wound bed was cultured every 12 days., Results: SPF-treatment wounds had significantly decreased wound area and decreased granulation tissue scores when evaluated <30 days and over the 60 day study, although complete wound healing times were not significantly different. Bacteria were cultured from all wounds at varying times throughout the study., Conclusions: The SPF wound dressing improved some measures of wound healing compared with the control dressing, most significantly during the first 30 days. This suggests that the SPF wound dressing may be useful in the early management of wounds on the equine lower limb. Further studies using the SPF dressing are needed to characterize the temporal and cellular effects on wound healing and evaluate this dressing in a clinical environment., (© Copyright 2014 by The American College of Veterinary Surgeons.)

Objective: To determine if preoperative physical examination and blood work values, intraoperative physiologic variables, and intraoperative treatments can be correlated with survival to anesthetic recovery and short-term survival to hospital discharge in horses that undergo exploratory celiotomy for large colon volvulus (LCV) with and without colon resection., Study Design: Retrospective case series., Animals: Horses (n = 156) undergoing exploratory celiotomy for correction of LCV ≥ 360(ο) ., Methods: Medical records (January 2000-December 2009) of horses that had surgical correction of LCV ≥ 360(ο) were reviewed. Data collection included signalment, preoperative physical examination variables and hematologic values as well as intraoperative physiologic variables, intraoperative treatments, and arterial blood gas values. Risk factors for survival to anesthetic recovery and hospital discharge were determined using exact logistic regression., Results: High preoperative heart rate and packed cell volume were associated with not surviving to anesthetic recovery or hospital discharge. A low intraoperative total serum protein concentration was associated with not surviving to anesthetic recovery or to hospital discharge. Intraoperative tachycardia and hypercapnia were associated with not surviving to hospital discharge. Intraoperative hypotension was a negative predictor of survival to anesthetic recovery. There was no increase in death for horses in which a resection and anastomosis was performed compared with those having manual correction., Conclusions: Several hematologic and cardiorespiratory variables that are easily measured preoperatively and intraoperatively show good correlation with postanesthetic survival in horses undergoing surgical correction of LCV. These measurements might be useful for prognosticating survival in horses admitted for correction of LCV ≥ 360(ο) ., (© Copyright 2012 by The American College of Veterinary Surgeons.)

Objective: To describe a technique for blind thoracoscopic-assisted double-lumen endobronchial tube (DLT) placement for achieving one-lung ventilation (OLV) using 3 different DLT designs and to evaluate whether thoracic auscultation could reliably confirm OLV in dogs., Study Design: Prospective randomized study., Animals: Mature female hound dogs (n = 6)., Methods: Physical examination, baseline blood work and thoracic radiography confirmed the absence of preexisting disease in all dogs. Thoracoscopic observation was established through a subxiphoid portal and used for evaluation of differential lung lobe ventilation. Each dog was sequentially intubated using 1 of 3 DLT designs in random order; Robertshaw left-sided tube (RS-L), Carlens left-sided tube (C-L), Dr. White right-sided tube (DW-R). Incidence of initial and overall (after a maximum of 3 DLT manipulations) correct and complete OLV (CC-OLV) was recorded. After each blind thoracoscopic-assisted DLT placement, bronchoscopic evaluation was performed to document correct DLT position., Result: Blind DLT placement achieved overall CC-OLV in all dogs using RS-L, 66% using C-L, and all using DW-R. Successful initial left-sided OLV (L-OLV) was statistically more likely when RS-L DLTs were used compared to C-L or DW-R. Of cases where overall CC-OLV was achieved, correct DLT position was present in only 44% of intubations., Conclusions: Blind DLT placement produced successful CC-OLV in all dogs using at least one DLT design evaluated. Use of thoracoscopic assistance may obviate the need for bronchoscopic observation during DLT placement in dogs. However, bronchoscopic observation may still refine DLT positioning in dogs after blind thoracoscopic-assisted DLT placement., (© Copyright 2012 by The American College of Veterinary Surgeons.)

Objective: To (1) determine if histologic scores of pelvic flexure biopsies can predict short-term survival in horses with large colon volvulus (LCV) and (2) identify clinical variables predictive of short-term survival., Study Design: Case series., Animals: Horses (n = 28) with LCV (≥ 360°)., Methods: Medical records (January 2000-February 2008) of 28 horses were reviewed and clinical data recorded. Pelvic flexure biopsies were reviewed by 2 board-certified veterinary pathologists, unaware of clinical history and outcome, using 2 scoring systems. Exact logistic regression analysis was used to determine the relationship between histopathology scores (tissue viability), clinical data, and short-term survival (hospital discharge)., Results: Twenty-four horses (86%) survived to hospital discharge. Using a similar cutoff, neither scoring system was capable of predicting short-term survival. One scoring system failed to correctly predict clinical outcome in 5/25 horses (20%) and the other failed in 6/28 horses (22.4%). Heart rate (at admission and 24 hours after surgery) and packed cell volume 24 hours after surgery were significantly associated with short-term survival., Conclusion: Histopathologic evaluation of pelvic flexure biopsies did not accurately predict short-term survival in a significant proportion of horses with LCV in this study., (© Copyright 2012 by The American College of Veterinary Surgeons.)

Objectives: To evaluate clinical outcome in dogs after renal transplantation and determine predictors of outcome., Study Design: Retrospective case series., Animals: Dogs (n = 26) that had renal allograft transplantation., Methods: Medical records (1994-2006) of 26 consecutive cases of dogs that had kidney transplantation were reviewed. History, signalment, pre- and postoperative clinicopathologic and monitoring variables, postoperative complications, immunosuppressive therapy, and survival were recorded., Results: Median survival was 24 days (range, 0.5 to 4014 days) with a probability of survival to 15 days of 50% and the 100-day survival probability was 36%. Cause of death was attributed to thromboembolic disease in 8 dogs, infection in 6 dogs, and rejection in 1 dog. The only factor significantly associated with an increased likelihood of death was increasing age at time of surgery (P = .024)., Conclusions: Canine renal transplantation in clinical patients is associated with a high morbidity and mortality and increasing recipient age has a negative association with outcome. Thromboembolic complications are a major cause of death in the immediate postoperative period and effective anticoagulation protocols may greatly improve survival in the future., (© Copyright 2012 by The American College of Veterinary Surgeons.)

Objective: To report the prevalence of hypophosphatemia after renal transplantation in a historical cohort of cats., Design: Case series., Animals: Cats (n=86) that received a renal allograft., Methods: Medical records (January 200-June 2006) were reviewed. Signalment, clinical signs, pre- and postoperative diet, pre- and postoperative clinicopathologic variables, renal histopathology, and outcome were retrieved. Prevalence, onset, duration, treatment and associated clinical signs of hypophosphatemia were recorded. A chi(2) test was used to compare hemolysis frequency between cats with normal serum phosphorus concentration or a single spurious low serum phosphorus concentration for <24 hours duration (group 1) and confirmed hypophosphatemia for >24 hours (group 2). A Cox proportional hazards model was used to evaluate the effects of hypophosphatemia on survival while controlling for other potentially confounding variables (age, sex, weight, body condition score, and pre- and 24 hours postoperative clinicopathologic variables)., Results: Eighty-six cats (mean age, 7.7 years) were identified. Hypophosphatemia occurred in 32 cats (37%), with a median onset of 2 days and median duration of 4 days. Treatment was initiated in 48 (56%) of hypophosphatemic cats. Survival and hemolysis frequency was not significantly different between groups, and no risk factors were identified., Conclusion: Hypophosphatemia occurs in cats after renal transplantation and does not affect survival., Clinical Relevance: The clinical importance of hypophosphatemia in renal transplant recipients remains unknown.

Objective: To compare the diagnostic yield of conventional radiographs and computed tomography (CT) images of the skulls of dogs and cats with maxillofacial trauma (MFT)., Study Design: Prospective study., Animals: Dogs (n=9) and 15 cats with MFT., Methods: CT-scans and skull radiographs (4 standard projections) for each animal were evaluated using a semi-quantitative scoring system for the ability to identify 26 predefined, clinically relevant anatomic features (Part 1), and 27 predetermined potential traumatic injuries (Part 2). For Part 1, mean scores for each anatomic feature were recorded for every view and imaging modality. For Part 2, studies were evaluated for the frequency of cases where each predetermined traumatic injury was identified., Results: Part 1: On radiographs it was easy to identify 17 of 26 anatomic features whereas 6 features were very difficult or impossible to identify on any view. All structures were considered easy or very easy to identify on CT. Scores for CT were lower than radiographs for evaluating dental occlusion and the integrity of the mandibular body. Part 2: CT scans demonstrated 1.6 times more maxillofacial injuries for dogs and 2.0 times more for cats than conventional radiographs. The average number of MFT injuries per animal by radiographs and CT-scan was 4.8 and 7.6 in dogs, and 3.8 and 7.7 in cats, respectively., Conclusion: CT is superior to conventional skull radiography for identification of anatomic structures and traumatic injuries in dogs and cats. Skull radiography is useful for visualizing the mandibular body and dental occlusion., Clinical Relevance: CT allows for accurate assessment, diagnosis and treatment planning of MFT in dogs and cats.

Objective: To determine the effect of humeral wedge and humeral slide osteotomies on force distribution between the articular surfaces of the humerus and the radius and ulna in normal canine thoracic limbs., Study Design: In vitro mechanical testing., Sample Population: Cadaveric canine right thoracic limbs (n=12)., Methods: Transarticular elbow force maps were measured using a tactile array pressure sensor in elbow joints of axially aligned limbs under 200 N axial load before and after humeral wedge and humeral slide osteotomies., Results: Loading induced 2 distinct areas of high forces that corresponded with the proximal articular surfaces of the radius and ulna. Mean force on the proximal articular surface of the ulna was reduced by 25% and 28% after 4 and 8 mm sliding osteotomies, respectively. Statistically significant differences were not observed for the wedge osteotomies., Conclusion: Humeral slide osteotomy significantly decreases force on the proximal articular surface of the ulna., Clinical Relevance: The proximal articular surface of the ulna contributes significantly to load transfer through the canine elbow joint. Abnormalities that significantly increase this force might contribute to canine elbow dysplasia, specifically fragmentation of the medial coronoid process and osteochondritis dissecans of the medial aspect of the humeral condyle. Under the conditions studied, the overall reduction in mean joint surface force across the proximal articular surface of the ulna after humeral slide osteotomy indicates that this technique merits further investigation for potential use in medial compartmental osteoarthritis of the canine elbow joint.

Objective: To determine the effects of 2 different, commonly used surfaces with different coefficients of friction on ground reaction forces in normal dogs., Study Design: Prospective, observational, single cross-over study., Animals: Dogs (n=10) with no gait abnormalities., Methods: Dogs were acclimated to the force plate and 5 valid trials for each dog and each limb were recorded. Velocity and acceleration were tightly controlled. Each dog was tested on both surfaces sequentially in different sequences. Data analysis was done on peak vertical force, peak impulse, breaking and propulsion peak forces and impulses. Three-way repeated measures analysis of variance was used to separately evaluate the effect of floor type on force plate measures in fore and hind limbs, while controlling for side (left versus right) and experimental replicate. P-values<.05 were considered significant. Mean force and 95% confidence interval for the 6 variables analyzed for all limbs on each surface were calculated., Results: There were no significant differences in ground reaction forces between the linoleum and the carpet surface for thoracic or pelvic limbs for all gait variables measured. There were no significant differences between each individual gait trial per dog between the right and left thoracic limbs trials nor differences between the right and left pelvic limb trials., Conclusions: Normal dogs had no change in their ground reaction forces on linoleum and carpet surfaces., Clinical Relevance: Kinetic results from multi-center or comparative trials will not be affected by use of either linoleum or carpet surfaces.

Objectives: To evaluate outcome in dogs with left divisional intrahepatic portosystemic shunts (PSS) treated by partial ligation (PL) or ameroid ring constrictor (ARC) placement on the left hepatic vein., Design: Retrospective study., Animals: Dogs (n=28) with left divisional intrahepatic PSS., Methods: Retrieved data from medical records of dogs with left divisional intrahepatic PSS that had PL (n=17) or ARC (n=11) were signalment, history, clinical signs, preoperative blood work, portal pressure measurements, ARC size, complications and postoperative technetium scintigraphy. Outcome assessed by owner interview 6 months-10 years after surgery was classified as excellent, good or poor. Differences were tested by exact chi2 test., Results: Major complications occurred in 3 dogs: coagulopathy (1 PL dog died), ascites (1 PL dog survived) and seizures (1 ARC dog died). Eight PL dogs had technetium portal scintigraphy; 1 dog was negative and 7 dogs positive for persistent shunting. Seven ARC dogs had scintigraphy; 4 dogs were negative and 3 positive for persistent shunting. In PL dogs, long-term clinical outcome was excellent (92%) or good (8%) whereas, in ARC dogs it was excellent (20%), good (50%) or poor (30%). This outcome difference between treatment groups was significant (P=.0012)., Conclusion: Dogs treated by PL had significantly better long-term outcome compared with ARC treated dogs., Clinical Relevance: Based on these data, ARC placement on the left hepatic vein in dogs with left-divisional intrahepatic PSS cannot be recommended.

Objective: To compare procedure time, complications, mortality, and short-term outcome in dogs with patent ductus arteriosus (PDA) treated by surgical ligation (SL) or transarterial coil occlusion (TCO)., Study Design: Retrospective study., Animals: Dogs with PDA (n=204)., Methods: Medical records of dogs treated for PDA were reviewed. Dogs treated by SL when it was the primary method used for PDA treatment (1993-1998) were compared with dogs treated by TCO when it was the primary method used for PDA treatment (1999-2003). Dogs treated during the transition between techniques, dogs treated with SL (1999-2003) and dogs treated with TCO before 1999, as well as dogs with pulmonary hypertension, or bidirectional or reversed (right-to-left) flow through the PDA were excluded from analysis., Results: Age, weight, gender distribution, and procedure times (P=.43) were similar for both groups. Major complications were more common with SL (12% versus 4.3%; P=.035) whereas minor complications were more common with TCO (12% versus 26%; P=.015). Initial success rate was higher for SL (94%) compared with TCO (84%; P=.027). There was no significant difference in mortality between SL (5.6%) and TCO (2.6%; P=.27)., Conclusions: Both SL and TCO are acceptable PDA treatments with comparable mortality; however, SL was associated with a higher risk of major complications and TCO was associated with a lower initial success rate.

Objective: To determine the relative importance of ischemic injury to delayed graft function (DGF) in cats., Study Design: Experimental study., Animals: Six intact female cats., Methods: Cats had renal autograft transplantation without ureteral transection and reimplantation and a contralateral nephrectomy. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured regularly and abdominal ultrasound was performed before surgery, the day after surgery and twice weekly thereafter. Ultrasound-guided renal biopsy was performed on day 7. Cats were euthanatized on day 21. Histology of the autograft, ureter, bladder, vascular anastomoses sites, and contralateral kidney were performed. Observations were compared with those from an historic group of research cats that had extravesicular ureteroneocystostomy and contralateral nephrectomy., Results: Five cats completed the study. Serum creatinine and BUN concentrations increased after surgery, peaking at 3.2+/-0.8 and 77.6+/-15.9 mg/dL, respectively, 1-2 days after surgery. Serum creatinine concentration returned to the reference interval by 6 days after surgery. BUN gradually decreased in all cats but did not return to the reference interval by study end. Serum creatinine and BUN concentrations were consistently lower but not significantly so (P=.29 and .56, respectively) compared with the historic ureteroneocystostomy group. No ultrasonographic abnormalities or renal biopsy histologic abnormalities were observed. At necropsy, 1 autograft had generalized interstitial fibrosis., Conclusion: Harvesting the renal graft and the ischemia before revascularization causes impaired renal function after engraftment., Clinical Relevance: The process of harvesting and reimplanting the renal graft can contribute to DGF in cats, independent of ureteral obstruction.

Objective: To compare radioulnar incongruence (RUI) of normal canine elbows and elbows with arthroscopically confirmed medial compartment disease in vivo using systematic computed tomography (CT) measurements., Study Design: Prospective comparison of RUI measurements in normal and dysplastic canine elbows., Sample Population: Right elbows of 25 medium-large breed, adult dogs with medial compartment disease and 9 medium-large breed, adult dogs with no elbow disease., Methods: Transverse CT images of proximal radioulnar articulation were reformatted to dorsal and sagittal planes. RUI in 3 locations of the forelimb's medial coronoid was measured. Arthroscopy confirmed diagnosis of medial compartment disease in the diseased group. RUI measurements of the diseased and normal elbows were compared., Results: Cumulative statistical analysis of RUI in all planes revealed no significant difference between the normal and abnormal elbows (P = .61). The abnormal elbows had negative mean RUI at the mid (P = .56) and cranial (P = .24) coronoid regions that were not significantly different from normal elbows and mean positive RUI at the base coronoid that was significantly greater than in normal elbows (P = .00082)., Conclusion: Canine elbows with established medial compartment disease do not have significant RUI at the medial coronoid region at the time of diagnosis when compared with normal elbows., Clinical Relevance: If RUI is a significant factor in the pathophysiology of medial compartment elbow disease in the dog, it does not appear to be present at the time of diagnosis of disease. Ulnar or radial osteotomies do not appear to be indicated for restoration of normal radioulnar articular surface alignment.

Objective: To compare 3 techniques for ureteroneocystostomy in cats., Study Design: Experimental surgical study., Animals: Fifteen adult cats., Methods: Cats (15) had ureteroneocystostomy with ureteronephrectomy of the contralateral kidney: 5 cats had an intravesical mucosal apposition technique (modified Leadbetter-Politano; intravesical-MA group), 5 cats had extravesical ureteroneocystostomy (modified Lich Gregoir) using a simple continuous suture pattern (extravesical-SC group) and 5 cats had an extravesical technique using a simple interrupted suture pattern (extravesical-SI group). Renal function was evaluated by measuring serum creatinine concentration. Ultrasonographic assessment of the kidney and ureteroneocystostomy site was performed the day after surgery, twice weekly for 3 weeks and once weekly for the remainder of the study. Cats were euthanatized 50 days after surgery. The kidney and ureter removed at surgery, the remaining kidney, ureter, ureteroneocystostomy site, and bladder were examined histologically., Results: Two extravesical-SC cats were euthanatized because of azotemia and uroabdomen, and 1 died acutely at day 4 for unknown reasons. In the intravesical-MA and extravesical-SI cats, the serum creatinine concentration increased after surgery, peaking at a mean (+/-SD) of 9.4+/-2.4 mg/dL and 4.9+/-3.3 mg/dL on day 3, and decreasing to 3.4+/-5.7 mg/dL and 1.5+/-0.4 mg/dL on day 7, respectively. The extravesical-SI technique was associated with consistently lower serum creatinine concentrations for the first week after surgery compared with the other techniques. The mean serum creatinine concentration was within the reference range in cats in the intravesical-MA and extravesical-SI groups by days 10 and 5, respectively. Renal pelvic dilatation occurred in all cats but resolved more rapidly in cats after extravesical techniques. There was no significant difference in serum creatinine concentrations or renal pelvic dilation between the intravesical-MA and extravesical-SI techniques. Bladder mass height at the anastomosis site was significantly larger and persisted for longer with intravesical-MA technique., Conclusion: An extravesical-SI technique is seemingly the choice for ureteroneocystostomy in cats with undilated ureters. Renal pelvic dilation on ultrasound examination should be expected after ureteroneocystostomy in cats., Clinical Relevance: An extravesical ureteroneocystostomy technique using a simple interrupted pattern for anastomosis should be considered in cats undergoing renal transplantation.

Objective: To evaluate the accuracy of linear measurements obtained from computer tomography (CT) images of staged radio-ulnar incongruence in a canine cadaver forelimb model., Study Design: CT evaluation of induced progressive radio-ulnar incongruence in canine cadaveric forelimbs., Sample Population: Eight cadaveric canine left forelimbs., Procedure: A type 2 external skeletal fixator (ESF) with linear motors was attached to the radius in 8 cadaveric left canine forelimbs. Contiguous incremental and helical CT images of the proximal radio-ulnar articulation were acquired in the transverse, sagittal and dorsal planes. The radius was shortened by 1, 2, and 4 mm increments and scanning protocols were repeated at each increment. Digital caliper and CT image analysis measured the progressive change in distance between 2 marking spheres and the epiphyseal bone surfaces of the radio-ulnar articulation. Statistical analysis of measurements from incremental and helical CT acquisitions, and direct and reformatted images were compared with inter-sphere distance using Pearson product moment correlation coefficients., Results: The reformatted incremental acquisition series at the mid-coronoid in the oblique plane had the highest correlation coefficient (r-value) at 0.908. The mid-coronoid in the dorsal plane had the second highest r-value (0.856). The coronoid incisure in the sagittal plane had an r-value of 0.826. The reformatted incremental acquisition series at the coronoid incisure in the oblique plane had the lowest r-value, 0.592., Conclusion: Measurement of radioulnar incongruence may be best performed using reformatted incremental acquisition CT in the mid-coronoid region in an oblique plane., Clinical Relevance: Use of the technique reported in this study may enable determination of the association, if any, between radioulnar incongruence and developmental diseases of the canine elbow.

Objective: To compare the biomechanical properties of radial graft (RG) versus ulnar transposition graft (UTG) limb-sparing techniques in the dog., Study Design: Cadaveric study., Animals: Six pairs of normal canine thoracic limbs., Methods: In each pair of limbs, 1 limb was subjected to the RG technique and the other to the UTG technique. Limbs were tested in axial loading until failure. Modes of failure and biomechanical properties were compared between the 2 groups. Percent coverage of the metacarpal bone by the plate was retrospectively compared between the limbs that failed by fracture of the metacarpal bones and those that did not., Results: RG limbs had significantly greater stiffness, yield load, maximum load, maximum energy, and post-yield energy. All UTG limbs failed by cranial bending of the plate. Half of the RG limbs failed by caudal bending of the plate and half by fracture of the third metacarpal bone at the distal end of the plate. Limbs with <80% plate coverage of the metacarpal bone were significantly more likely to fail by metacarpal fracture., Conclusions: The RG technique was biomechanically superior to the UTG technique under the conditions studied. At least 80% plate coverage of the metacarpal bone should be achieved., Clinical Relevance: Exercise restriction and coaptation bandages should be considered for patients undergoing the UTG technique to minimize potential biomechanical complications.

Objective: To determine the sensitivity and specificity of radiographic evaluation of radio-ulnar incongruence in canine elbow joints in vitro., Study Design: Radiographic evaluation of induced radio-ulnar incongruence in canine cadaveric forelimbs by radiologists blinded to study design., Sample Population: Six cadaveric canine left forelimbs., Methods: Extended lateral, 90 degrees flexed lateral, and cranio-caudal projections were taken of the elbow joint of six cadaveric canine forelimbs. A four-pin, type I external skeletal fixator (ESF) with a linear motor side bar was attached to the medial aspect of the radius, and a 2-cm segment of bone was removed from the mid-diaphysis. A 3.5-mm cortical bone screw placed from the medial to lateral styloid processes prevented relative movement between the distal radius and ulna during radial shortening. The ESF was used to progressively shorten the radius in increments of 0.5 mm to a total of 4 mm. The three radiographic projections were repeated after each incremental change of length. After the study, each elbow joint was disarticulated to confirm the presence of a step defect. The original radiographs and three copies were randomized and then evaluated by four radiologists blinded to the study design. Radiologists were asked to evaluate whether the joint was normal or abnormal and if there was evidence of radio-ulnar incongruence. The ability of each radiologist to correctly identify congruent elbows (specificity) and incongruent elbows (sensitivity) was calculated., Results: The median specificity was 86% using the lateral projection and 82% using the cranio-caudal projection. The median sensitivities using the lateral and cranio-caudal radiographic projections were 78% and 79%, respectively. The degree of radial shortening required for individual radiologists to achieve a sensitivity of 90% ranged from 1.5 mm to greater than 4 mm., Clinical Relevance: Standard radiographic evaluation for radio-ulnar incongruence in the dog may be associated with relatively poor sensitivity and specificity. Invasive surgical procedures and screening programs that rely on radiographic diagnosis of radio-ulnar incongruence should be discouraged until a more reliable method of diagnosis of this type of elbow joint incongruence is available., (Copyright 2002 by The American College of Veterinary Surgeons)

Objective: To determine the effect that ventral intervertebral disk fenestration has on the sagittal range of motion about the C5-C6 intervertebral space., Study Design: A repeated measures in vitro mechanical study of spinal range of motion under controlled loading conditions before and after fenestration., Sample Population: A total of 10 canine cervical vertebral specimens (C4-C7) collected from clinically normal animals within 12 hours of euthanasia., Methods: Specimens were loaded as cantilever beams fixed at C7. Weights (1 to 5 kg) were progressively applied to C4 to produce flexion or extension in the sagittal plane. Radiographs were taken at each load, 3 times before and 3 times after fenestration of the C5-C6 disk. The positions of radiodense markers embedded in the vertebrae were used to calculate flexion and extension angles and range of motion., Results: Range of motion (difference between flexion and extension) and flexion and extension angles (individually) significantly increased after fenestration (P < .0001)., Conclusion: Ventral fenestration produces sagittal instability of the C5-C6 disk space., Clinical Relevance: In surgical fusion of caudal cervical intervertebral spaces in dogs, radiographically normal disks adjacent to the affected space are often fenestrated to facilitate distraction before surgical stabilization. This study shows that ventral fenestration produces instability of a caudal cervical intervertebral space in the model used. Such instability may contribute to the development of the secondary instability ("domino lesions") seen in some surgically treated dogs.

Abnormal accumulations of lipid droplets, localized predominantly in histochemical type 1 fibers, were observed in fresh frozen sections of muscle biopsies from 25 dogs with myalgia, weakness, and muscle atrophy. Compared to controls, lactic acidemia, hyperalaninemia, lactic and pyruvic aciduria, variably increased urinary excretion of carnitine esters, and muscle carnitine deficiency were present. These findings support a metabolic block in oxidative metabolism resulting in lactic acidemia in dogs with lipid storage myopathy.

Objective: The purpose of this study was to determine the tumor-free interval and survival times of cats who had one (group 1) or more (group 2) surgeries, or surgery and radiation therapy (RTH) (group 3) for treatment of soft tissue fibrosarcomas (FSA)., Study Design: Retrospective study., Animals or Sample Population: 45 client-owned cats., Methods: Medical records of cats with soft tissue FSA were examined. Vaccination and feline leukemia virus (FeLV) status, age, sex, breed, tumor location, number of surgeries, completeness of excision, and histopathological grade were evaluated to correlate with tumor-free interval and survival periods., Results: Overall median tumor-free interval and survival times were 10 and 11.5 (range, 1 to 40) months. Median tumor-free interval and survival times were more than 16 months each in group 1, more than 5 and 13 months in group 2, and 4.5 and 9 months in group 3. Age, sex, breed, vaccination or FeLV status, tumor location, or histopathological grade did not affect median tumor-free interval or survival times (P > .05). Cats with complete excisions had significantly longer median tumor-free interval (> 16 versus 4 months) and survival time (> 16 versus 9 months) than those with incomplete excisions (P = .008). Radiation therapy did not seem to extend tumor-free interval and survival times (P = .013). However, most group 3 cats had incomplete surgical excisions, resulting in recurrent or progressive disease., Conclusions: Complete surgical excision of FSA in cats is possible and can be curative., Clinical Relevance: Aggressive surgical excision with wide margins appears to contribute to extended tumor-free interval and survival times in cats with soft tissue FSA. Controlled prospective studies are needed to determine the efficacy of RTH in treatment.

This study determined the effect of the polypeptide growth factors transforming growth factor-beta (TGF-beta), insulin-like growth factor-I (IGF-I), and growth hormone (GH) alone and in combination with dietary L-Arginine HCL (ARG) on skin flap survival in rats. Caudally based dorsal skin flaps were created in 110 Sprague-Dawley rats. The rats were randomly assigned into three treatment groups, based on drinking water supplementation. Group 1 (n = 50) received ARG in their drinking water, group 2 (n = 50) received tap water alone, and group 3 (n = 10) received N-omega-nitro-L-arginine (L-NA) and hydralazine. Groups 1 and 2 were divided into subgroups of 10 rats each based on treatment with either: TGF-beta, IGF-I, GH, or IGF-I + GH. All subgroups that received GH had significantly greater (P < .0001) median body weight gains when compared with subgroups not receiving GH. L-arginine HCL when added to IGF-I negated the positive effects of IGF-I on both flap survival and weight gain. Although the rats in all subgroups from groups 1 and 2 had an increase in mean percent skin flap survival when compared with the water alone subgroup, only rats receiving IGF-I, or the combination of ARG with either TGF-beta or GH, had statistically significant enhanced skin flap survival. Rats in group 3 did not show an increase in skin flap survival when compared with the control subgroup.