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Gastrointestinal disease has been associated with shedding of Salmonella with previous studies demonstrating that horses with colic have a higher risk of acquiring and shedding Salmonella organisms.The purpose of this study was to determine the prevalence of and risk factors associated with Salmonella shedding in a colic population at a referral clinic.Retrospective case-control study.For each colic case that was positive for Salmonella (n = 56), two colic cases (n = 112) that tested negative for Salmonella, were enrolled as controls. Associations between variables and Salmonella shedding were identified using logistic regression. Univariate and multivariable models were developed pertaining to (1) presenting clinicopathological data and (2) clinical variables that developed during hospitalisation.Of the equids presenting with colic, 1585/1917 had a sample submitted for Salmonella testing. Of these, 56 were positive for Salmonella yielding a prevalence of 3.5%. Equids shedding Salmonella were more likely to present in July (odds ratio [OR] = 7.2; 95% confidence interval [CI] = 1.63-32.13; p = 0.009) and present with a history of fever (OR = 53.5; 95% CI = 2.57-1113.03; p = 0.01), increased lactate (OR = 1.6; 95% CI = 1.14-2.29; p = 0.007) and/or neutropenia (OR = 0.79; 95% CI = 0.65-0.97; p = 0.02). Hospitalised equids shedding Salmonella were more likely to be febrile (OR = 4.8; 95% CI = 1.47-15.8; p = 0.01) and 10 times more likely to develop reflux (OR = 10.1; 95% CI = 1.67-61.43; p = 0.01) compared to colic controls.Retrospective nature of the study and bias inherent to the retrieval of data from medical records cannot be discounted. Classifying Salmonella status based on a single sample may have resulted in misclassification bias.The prevalence of Salmonella shedding in this colic population was low compared to earlier reports. Certain predictors such as the development of a fever or reflux in hospitalised colic cases were associated with Salmonella shedding and may help the clinician to promptly identify horses likely to shed; thus, helping institute effective use of barrier nursing precautions.背景: 胃肠道疾病与沙门氏菌散播有关；先前的研究表明，有腹痛的马匹有更高罹患和散播沙门氏菌的风险。 目的: 本研究的目的是确定由于腹痛进入转诊医院马匹中，沙门氏菌散播的流行率和相关的危险因素。 研究设计: 回顾性病例对照研究 方法: 对每一例沙门氏菌阳性的腹痛病例(n = 56)，选两例沙门氏菌阴性的腹痛病例(n = 112)作为对照。各种变量与沙门氏菌散播之间的联系使用逻辑回归确定。建立单变量和多变量模型研究以下联系:(1)临床病理数据，(2)住院期间产生的临床变量。 结果: 在1917匹发生腹痛的马匹的样本中，1585匹完成了沙门氏菌检测。其中56例沙门氏菌阳性，患病率为3.5%。马属动物散播沙门氏菌常出现在7月份(OR = 7.2; 95% CI = 1.63-32.13; p = 0.009)。常伴随发热史(OR = 53.5；95% CI = 2.57-1113.03；p = 0.01)，乳酸升高(OR = 1.6；95% CI = 1.14-2.29；p = 0.007)和/或中性粒细胞减少(OR = 0.79；95% CI = 0.65 -0.97；p = 0.02)。住院马匹散播沙门氏菌的更可能发热(OR = 4.8；95% CI = 1.47 -15.8；p = 0.01)，和阴性腹痛对照组相比，发生胃返流的可能性增加10倍(OR = 10.1；95% CI = 1.67 -61.43；p = 0.01)。 主要限制: 回顾性研究的性质和从医疗记录中检索数据的固有主观性局限。基于单一样本对沙门氏菌状态进行分类可能会导致分类偏差和不合理。 结论: 与早期报道相比，该设计中马匹的沙门氏菌散播流行率较低。某些预测因素，如发烧或返流在住院腹痛病例中与沙门氏菌散播相关，可以帮助临床医生及时识别可能散毒的马匹，从而帮助建立有效的屏障以及护理预防措施。.

Equine toxicologic emergencies are relatively uncommon but can cause significant morbidity and mortality in a group of comanaged horses. The field veterinarian's role is to triage the situation, as well as the individual animal. Individual patient stabilization should focus on support of essential organ functions, providing time for treatments to have an effect or for elimination of the toxicant. Decontamination procedures can follow patient stabilization, if appropriate. Antidotes are often not available or feasible for equine intoxications. The field veterinarian should emphasize triage and stabilization before referral and on-site identification and collection of diagnostic samples to support the diagnosis.

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

OBJECTIVE To assess the diagnostic value of plasma and peritoneal fluid procalcitonin concentrations for identification of horses with strangulating intestinal lesions. ANIMALS 65 horses with signs of colic of intestinal origin and 10 healthy (control) horses. PROCEDURES For each horse, plasma and peritoneal fluid samples were obtained for a CBC and determination of total protein, procalcitonin, and lactate concentrations. Signalment and clinicopathologic findings were compared among control horses and horses with strangulating and nonstrangulating intestinal lesions. RESULTS Mean ± SD plasma (274.9 ± 150.8 pg/mL) and peritoneal fluid (277 ± 50.6 pg/mL) procalcitonin concentrations for horses with colic were significantly greater than the mean ± SD plasma (175.5 ± 46.0 pg/mL) and peritoneal fluid (218.8 ± 48.7 pg/mL) procalcitonin concentrations for control horses. Mean procalcitonin concentration in peritoneal fluid, but not plasma, differed significantly between horses with strangulating lesions and those with nonstrangulating lesions. A peritoneal fluid procalcitonin concentration ≥ 281.7 pg/mL had a sensitivity of 81%, specificity of 69%, positive predictive value of 56.7%, and negative predictive value of 87.9% for detection of strangulating lesions. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that peritoneal fluid procalcitonin concentration, when evaluated in conjunction with other clinicopathologic results, might be a sensitive indicator of intestinal ischemia and facilitate early identification of horses that require surgery to address a strangulating lesion.

BackgroundIncisional complications are a common cause of morbidity following laparotomy. Although uncommon, acute abdominal dehiscence (AAD) is a potentially fatal post-operative complication. However, few AAD cases are described in the literature.ObjectivesTo describe common features of cases of AAD following ventral midline laparotomy, management and outcomes.Study designRetrospective case series.MethodsHospital records of horses that underwent a ventral midline laparotomy at nine hospitals in the UK, Ireland and USA over a 10-year period (2009-2019) were reviewed. Data were collected for pre-, intra- and post-operative factors that were considered relevant. Descriptive statistical analysis was performed.ResultsA total of 63 cases of AAD were identified. AAD occurred due to tearing of sutures through the linea alba or rupture of the body wall adjacent to the suture line in 46 horses (73%). AAD occurred at a median of 5 days (0.5-70 days) post-operatively and broodmares accounted for 25% of the cases (n = 16). Surgical site infection developed prior to AAD in 28 horses (44%); leakage of peritoneal fluid occurred in 5% of horses prior to AAD being identified. Surgical repair was performed in 27 horses (43%), 10 (16%) were treated conservatively and 26 (41%) were euthanised immediately. Repair was most frequently performed using suture (n = 14), wire (n = 5) or a combination (n = 5). Overall survival to hospital discharge was 39% (24/63). Where surgical repair was performed, 15 horses (56%) survived to hospital discharge; 9 horses (90%) managed conservatively survived to hospital discharge.Main limitationsFollow-up was not performed for all cases following hospital discharge and some data were incompletely recorded in hospital files.ConclusionsPreviously stated causative factors for AAD were not consistent features in the present study. Surgical site infection following laparotomy and pregnant or early post-partum mares may be important risk factors for AAD and warrant further investigation.

Despite increasing representation of women in veterinary medicine, gender differences persist in pay and attainment of senior and leadership positions. In academia, scholarly publication is a measure of productivity and is emphasized in the promotion process. This study aimed to analyze gender differences in the authorship of veterinary research articles to understand factors that could influence women’s advancement and standing in academic medicine. We hypothesized that the proportion of women authors would increase between 1995 and 2015 and be similar to employment rates of women in academia, and that gender differences would exist in authorship by species, veterinary specialty area, and role (junior versus senior author). We examined 2,086 articles published in eight prominent veterinary journals in 1995 and 2015, determined the gender of first authors, corresponding authors, and senior authors, and collected article information including study design, species, and veterinary specialty area. The proportion of women as first and corresponding author increased significantly between 1995 and 2015, and in both years studied, women authored a larger percentage of articles than the reported percentage of women working in academia. In 2015, women were first authors of 60.0% (95% CI 56.9–63.0) of articles but accounted for only 38.3% of senior authors (95% CI 33.4–43.3). Female first authors were concentrated in articles pertaining to small animal, equine, and internal medicine disciplines and under-represented among articles pertaining to livestock or surgical specialties. The gender gap in the authorship of veterinary clinical research articles has improved dramatically over the past 20 years, although gender disparities persist.

OBJECTIVE To assess incidence of incisional infection in horses following management with 1 of 3 protective dressings after exploratory celiotomy for treatment of acute signs of abdominal pain (ie, colic) and determine the risk of complications associated with each wound management approach. DESIGN Prospective, randomized, controlled study. ANIMALS 85 horses. PROCEDURES Horses were assigned to 3 groups. After standardized abdominal closure, a sterile cotton towel (group 1) or polyhexamethylene biguanide–impregnated dressing (group 2) was secured over the incision site with 4 or 5 cruciate sutures of nonabsorbable monofilament, or sterile gauze was placed over the site and secured with an iodine-impregnated adhesive drape (group 3). Demographic and clinicopathologic data, intraoperative and postoperative variables, and development of complications were recorded and compared among groups by statistical methods. Follow-up information was collected 30 and 90 days after surgery. Incidence and odds of incisional complications were calculated. RESULTS 75 horses completed the study. Group 3 typically had dressing displacement necessitating removal during anesthetic recovery; dressings were in place for a mean of 44 and 31 hours for groups 1 and 2, respectively. Purulent or persistent serosanguinous incisional discharge (ie, infection) was detected in 11 of 75 (15%) horses (2/24, 0/26, and 9/25 from groups 1, 2, and 3, respectively). Odds of incisional complications were significantly greater for group 3 than for groups 1 or 2. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that risk of infection after celiotomy for treatment of colic is lower for incisions covered with sterile towels or polyhexamethylene biguanide–impregnated dressings secured with sutures than for incisions covered with gauze secured with iodine-impregnated adhesive drapes.

Author(s): Fielding, C Langdon; Mayer, Jennifer R; Dechant, Julie E; Epstein, Kira L; Magdesian, K Gary | Abstract: BackgroundTrauma from dog attacks has been associated with mortality rates as high as 23% in some species. However, the prognosis and clinical features of this type of injury have not been described in equids.Hypotheses/objectivesTo describe survival rate, signalment, clinical features, and biochemical results in equids presented for emergency care after presumed dog attacks. We hypothesized there would be differences between survivors and nonsurvivors.AnimalsA total of 28 equids presented for presumed dog attacks from 3 referral centers.MethodsA retrospective study was performed using data from 3 hospitals between 2008 and 2016. Survival was defined as survival at 14 days postdischarge. Variables were compared between survivors and nonsurvivors using a t test, Mann-Whitney U test, or Fisher's exact test as appropriate.ResultsOverall mortality rate was 21%. Ponies and miniature horses represented 16/28 (57%) of the animals in the study. Full-sized equids had a lower risk of nonsurvival as compared to smaller patients (odds ratio = 0.02; 95% confidence intervals = 0.00-0.27; P l .005). Animals with lower body temperatures had increased risk for nonsurvival (P = .0004). Increased admission blood lactate concentrations (P = .003) and decreased serum total protein concentrations (P = .006) were associated with nonsurvival.ConclusionsThe mortality rate in equids attacked by dogs was similar to what is reported for other veterinary species. Smaller equids and those with increased admission blood lactate concentration, lower body temperature, and lower total serum protein concentrations were less likely to survive.

Auditory loss has been reported in camelids using brainstem auditory evoked responses (BAER). Differentiation between conductive versus sensorineural dysfunction has not been investigated. Therefore, the objective of the study was to investigate auditory function using BAER and bone conduction (BC). Twenty-four alpacas: 15 females, 9 intact males (2–16 years of age) were included in a randomized clinical trial. BAER and BC were recorded using two derivations (vertex to mastoid and vertex to cranial aspect of second cervical vertebra). All alpacas underwent complete physical examinations and were sedated with xylazine hydrochloride at 0.6 mg/kg IM. Peaks, when present, were identified and latencies, amplitudes, and amplitude ratios were determined. Eleven alpacas had normal responses and 13 had auditory loss based on BAER. The latter consisted of complete absence of peaks bilaterally (n = 3), absence of peaks unilaterally (n = 1), delayed latencies bilaterally (n = 4), and delayed latencies unilaterally (n = 5). Distinct peaks on BC supported conductive auditory loss in 6 alpacas, difficult to interpret due to stimulus artifact and additional undefined peaks in 4, and absent peaks in 3 alpacas. The cause of auditory loss was presumed to be due to otitis in 6, aging in 4 (10–16 years old), and congenital sensorineural (absent peaks on BAER and BC) in 3 alpacas with unpigmented fiber and irises. BAER and BC are useful and non-invasive to perform techniques for the investigation of auditory loss in alpacas, and further characterization as conductive or sensorineural.

This study reports the prevalence of and risk factors for incisional complications in equids after ventral midline celiotomy for enterolithiasis. This study covered the years 2008 to 2015 and included 72 equids. Enteroliths were removed from the ascending or descending colon through 1 or more enterotomies. Complications were defined as surgical site infection and/or incisional hernia formation. Follow-up by telephone questionnaire or medical records determined that 10/72 (13.9%) equids experienced complications, with 6/72 (8.3%) developing a surgical site infection and 5/72 (6.9%) a hernia. Seven of ten were presented for chronic abdominal discomfort (> 24 hours), and 8/10 had right dorsal colon and pelvic flexure enterotomies. All equids that developed an incisional hernia and 4 with surgical site infection had enteroliths > 15 cm diameter removed from the right dorsal colon. Antimicrobial powder applied to the ventral midline incision during closure significantly reduced incisional complications. Removal of > 15 cm diameter enteroliths from the right dorsal colon may predispose to postoperative incisional complications.

Objective To identify etiology, clinical findings, diagnostic results, treatment, and short- and long-term survival and to report factors associated with nonsurvival and survival in horses with peritonitis. Study design Retrospective study. Animals Horses (n = 72). Methods Medical records at William R. Pritchard Veterinary Medical Teaching Hospital from 2007-2017 were reviewed for horses diagnosed with peritonitis. The essential inclusion criterion was a peritoneal nucleated cell count of ≥25 000 cells/μL. Gastrointestinal rupture and cases in which peritonitis occurred after abdominal surgery or castration were excluded. Information retrieved from medical records included signalment, history, clinicopathological and peritoneal fluid variables, diagnostic imaging findings, inciting cause, treatment, and short- and long-term survival. Data were analyzed by using Fisher's exact test, Wilcoxon rank sum test, and χ2 test (P Results Colic was the most common presenting complaint (34/72 [48%]). A definitive diagnosis could be made in 44 (44/72 [61%]) cases. The most common cause of peritonitis was infectious agents (31/72), followed by trauma (8/72), gastrointestinal thickening (3/72), and eosinophilic peritonitis (2/72). Idiopathic peritonitis was identified in 28 (28/72 [39%]) cases. Sixty (83%) horses survived to hospital discharge. Long-term follow-up was available for 49 horses, with 43 (88%) horses alive 1 year after discharge. Significant differences between nonsurvivors and survivors were history of colic, positive peritoneal fluid culture, and several hematological/peritoneal fluid variables. Conclusion Peritoneal fluid analysis was essential for a definitive diagnosis of peritonitis, and certain variables were useful for predicting outcome. Clinical significance Results of this study provide evidence of the value of peritoneal fluid analysis for identification of peritonitis, prediction of outcome, and successful treatment.

OBJECTIVE To describe clinical features and outcome of horses with severe large intestinal thickening diagnosed with transabdominal ultrasonography. DESIGN: Retrospective case series. ANIMALS 25 horses. PROCEDURES Medical records of horses that underwent transabdominal ultrasonography between 2003 and 2010 were reviewed. Horses were included if the wall of the large intestine was ≥ 9 mm thick in any of 6 abdominal zones. RESULTS Median age was 13 years (range, 3 to 28 years). Horses were initially examined because of colic, diarrhea, inappetence, weight loss, lethargy, fever, or hematuria. Severe large intestinal thickening (range, 9 to 46.6 mm; mean ± SD, 18.8 ± 6.8 mm) was the primary ultrasonographic finding in all horses. Thickened large intestine was more likely to be detected in ventral versus upper (ie, combined paralumbar and intercostal) abdominal zones and in right versus left zones. Eleven horses survived and had resolution of clinical signs, including the l horse treated surgically for colon torsion. An additional horse survived but continued to have intermittent colic. Ten horses were euthanized or died, including 3 horses with neoplasia and 3 with colitis. Three horses were lost to follow-up, including 1 horse with a cecal mass and 1 with hepatosplenic lymphoma. Severity of thickening and number of zones affected were not significantly different between survivors and nonsurvivors. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that in horses undergoing transabdominal ultrasonography, large intestinal wall thickness ≥ 9 mm may be detected in patients with a variety of conditions. Ultrasonographic examination of all abdominal zones was helpful to determine the extent of thickening and identify additional findings that helped prioritize differential diagnoses.

OBJECTIVE To determine the maximum concentration (Cmax) of amikacin and time to Cmax (Tmax) in the distal interphalangeal (DIP) joint in horses after IV regional limb perfusion (IVRLP) by use of the cephalic vein. ANIMALS 9 adult horses. PROCEDURES Horses were sedated and restrained in a standing position and then subjected to IVRLP (2 g of amikacin sulfate diluted to 60 mL with saline [0.9% NaCl] solution) by use of the cephalic vein. A pneumatic tourniquet was placed 10 cm proximal to the accessory carpal bone. Perfusate was instilled with a peristaltic pump over a 3-minute period. Synovial fluid was collected from the DIP joint 5, 10, 15, 20, 25, and 30 minutes after IVRLP; the tourniquet was removed after the 20-minute sample was collected. Blood samples were collected from the jugular vein 5, 10, 15, 19, 21, 25, and 30 minutes after IVRLP. Amikacin was quantified with a fluorescence polarization immunoassay. Median Cmax of amikacin and Tmax in the DIP joint were determined. RESULTS 2 horses were excluded because an insufficient volume of synovial fluid was collected. Median Cmax for the DIP joint was 600 μg/mL (range, 37 to 2,420 μg/mL). Median Tmax for the DIP joint was 15 minutes. CONCLUSIONS AND CLINICAL RELEVANCE Tmax of amikacin was 15 minutes after IVRLP in horses and Cmax did not increase > 15 minutes after IVRLP despite maintenance of the tourniquet. Application of a tourniquet for 15 minutes should be sufficient for completion of IVRLP when attempting to achieve an adequate concentration of amikacin in the synovial fluid of the DIP joint.

Mental wellness is an important topic among practicing veterinarians. Peer reviewed studies focusing on veterinary house officers’ wellbeing are lacking in veterinary medicine. The aim of this study was to assess wellbeing of house officers using validated surveys for anxiety, burnout, depression, and quality of life. A cross-sectional survey of 103 house officers (residents, interns, and fellows) was performed. Respondents were invited to voluntarily complete the online surveys. Anxiety, burnout, depression, and quality of life were assessed using the Generalized Anxiety Disorder (GAD-7), Maslach Burnout Inventory (MBI), Patient Health Questionnaire (PHQ-9), and Short Form-8 (SF-8), respectively. Descriptive statistics were calculated. For qualitative analysis, respondents were requested to rate their perception of the level of stress regarding various work-related stressors. The first survey was completed in 2017 with 60 respondents of which 51 (85%) identified as females and nine (15%) identified as males. The second survey was completed in 2018 with 43 respondents of which 35 (81.4%) identified as females and 8 (18.6%) identified as males. Respondents reported high levels of burnout characterized by high levels of emotional exhaustion and lack of personal accomplishment but reported mild levels of anxiety and depression. The mental component of their quality of life score was lower than the general US population, whereas the physical component score was consistent with the general US population. Respondents indicated moderate scores of stress for concerns regarding patient management, research, teaching, work-life balance, relationships, organizational skills, time management, finances, and the mental and emotional impact of the work environment. The high levels of burnout, and low mental quality of life in house officers require specific intervention programs to improve wellbeing.

Objective To determine the influence of radiographic quantification of sand accumulation on the medical versus surgical management of large colon sand accumulations. To compare short- and long-term outcomes and complications associated with medical and surgical management of these horses. Study design Retrospective. Sample population A total of 153 horses. Methods Medical records and abdominal radiographs of horses presented for colic between 2004 and 2014 were reviewed. Severity of sand accumulation was quantified by tracing and measuring a region of interest with a commercial software program. Breed, weight, amount of sand, presence of diarrhea at presentation, treatment, and the development of complications were recorded. Results Records from 153 horses were reviewed. The mean cross-sectional area of sand accumulation was 692.9 cm2 (median = 658.7 cm2, 84.6-1780.7 cm2). Increased accumulation of gas on radiographs and abnormal transrectal examination findings were associated with an increased likelihood of surgery. The most common complication was the development of diarrhea (20.3%) with only 4 (2.6%) horses positive for Salmonella spp. Horses had a favorable prognosis, with 94.8% of horses treated medically and 94.7% of those treated surgically surviving to discharge. Conclusion Increased accumulation of gas on radiographs and transrectal palpation of impaction or intestinal gas distension increase the likelihood of surgery. Both medical and surgical treatments carry a good prognosis. Clinical relevance The sheer quantity of sand is not a factor when determining surgical intervention. Attention should be paid to the presence of increased gas accumulation on rectal or radiographic examination.

Objective To describe the successful management of a urethral stricture with an absorbable stent in a stallion. Study Design Clinical report. Animals Stallion with a urethral stricture. Results A 12-year-old Thoroughbred breeding stallion was evaluated for acute onset of colic. Uroperitoneum because of presumptive urinary bladder rupture, with urethral obstruction by a urethrolith, was diagnosed. The uroperitoneum was treated conservatively. The urethrolith was removed through a perineal urethrotomy. Approximately 15 weeks after urethrolith removal, the stallion presented with a urethral stricture. The stricture was unsuccessfully treated with an indwelling urinary catheter and 4 attempts at balloon dilation. Eight weeks after diagnosis of stricture, an absorbable polydioxanone (20 mm × 80 mm) urethral stent was implanted under percutaneous, ultrasound guidance. Urethroscopy was performed at 70, 155, and 230 days after stent placement and the endoscope passed through the affected site without complication. Urethroscopy at 155 days showed the stent had been reabsorbed. Follow-up 20 months after stent placement reports the stallion was able to void a normal urine stream. Conclusions Absorbable urethral stent placement was a feasible treatment for urethral stricture in this stallion.

Regional limb perfusion (RLP) in horses has proven to be a simple and effective technique for the treatment of synovial and musculoskeletal infections in the distal portion of the limbs. The ideal tourniquet time needed to achieve therapeutic synovial concentrations remains unknown. The pharmacokinetic effects of general anesthesia (GA) versus standing sedation (SS) RLP on synovial amikacin concentrations are not completely understood. This study investigated the pharmacokinetic effects of RLP under general anesthesia (GA) versus standing sedation (SS) on synovial amikacin concentration following 20 or 30 min tourniquet time. Using 1 g of amikacin RLP was performed in two groups of six horses (GA and SS). A pneumatic tourniquet was applied proximal to the carpus and maintained for 20 or 30 min. Two weeks later, the opposite treatment (20 or 30 min) was randomly performed in the opposite limb of horses in each group (GA and SS). Synovial fluid samples were collected from the metacarpophalangeal (MCP) and radiocarpal (RC) joints. Amikacin was quantified by a fluorescence polarization immunoassay. Regardless of the group, no significant difference in the synovial amikacin concentrations was noted between 20 and 30 min RLP. Mean synovial concentrations of amikacin in the standing sedated horses were significantly higher in the MCP joint at 30 min (P = 0.003) compared to horses under general anesthesia. No significant difference was noted for the RC joint.

Objective To determine if preoperative and intraoperative clinical variables correlate with resection and anastomosis (RA) in horses presenting with strangulating small intestinal (SI) lesions. Study design Retrospective case series. Animals Horses undergoing exploratory celiotomy for a strangulating SI lesion (n = 243). Methods The records of horses undergoing surgical correction for strangulating SI lesions from January 1, 2000 to December 31, 2017 were reviewed. Horses were categorized as treated with RA or not treated with RA. Obtained information included history, signalment, clinical findings, diagnostic test results, intraoperative findings, and survival to discharge. Univariable and multivariable analyses were used to compare data between horses treated with RA vs those not treated with RA (P = .05). Results In total, 172 SI lesions were resected, and 71 were not resected. Horses that had gastric reflux at admission to the hospital (odds ratio [OR] 5.56; 95% CI 1.76, 17.59) and horses with amotile SI according to abdominal ultrasonography (OR 9.69; 95% CI 3.09, 30.37) were more likely to undergo RA. Increased difference between peritoneal fluid and blood lactate was higher in horses that underwent RA (OR 1.55; 95% CI 1.12, 2.13). Survival to hospital discharge was lower in the group of horses that underwent RA compared with horses that did not undergo RA. Conclusion Resection and anastomosis of strangulating SI lesions was associated with several preoperative variables. Clinical significance This study highlights the value of preoperative diagnostic procedures in aiding intraoperative decision making and prognostication in horses presenting with strangulating SI lesions.

OBJECTIVE: To determine the ability of plasma and peritoneal creatine kinase (CK) to predict the presence of a strangulating lesion in horses presented for colic. STUDY DESIGN: Prospective clinical study. ANIMALS: Ten healthy control horses and 61 clinical colic cases. METHODS: Creatine kinase activity was measured in peritoneal fluid and plasma of 10 healthy horses and 61 horses presenting for colic (40 horses with nonstrangulating lesions and 21 horses with strangulating lesions). Information on other blood and peritoneal fluid variables, signalment, results from the physical examination, outcome, requirement for surgery, and lesion location and type were retrieved from the medical records of horses presenting for colic. RESULTS: A peritoneal CK cutoff level of 16 IU/L yielded a sensitivity of 95.2% and a specificity of 84.6% (positive predictive value [PPV] = 76.9% and negative predictive value [NPV] = 97%, respectively) for predicting a strangulating lesion. A peritoneal lactate cutoff level of 3.75 mmol/L yielded a sensitivity of 81% and a specificity of 92% (PPV = 85% and NPV = 90%, respectively) for predicting a strangulating lesion. CONCLUSION: Peritoneal CK concentration was a sensitive indicator of the presence of a strangulating lesion in horses presenting with colic, whereas peritoneal lactate concentration was a more specific indicator. CLINICAL SIGNIFICANCE: Measuring CK in peritoneal fluid may be a useful adjunct to clinical case presentation to accelerate the diagnosis and definitive treatment of horses presenting with strangulating intestinal lesions, thereby improving their outcome.

Objective To determine the effects of water temperature and cure time on cast strength. Study design Prospective randomized experimental study. Methods Two water temperatures were tested, 23°C (cold) and 42°C (warm). Cast constructs were made of 4-inch fiberglass casting material over a rubber mandrel. Each construct was divided into 3 segments and tested in 4-point bending at 0.5, 1, and 24 hours. Stiffness and bending moment, cumulative energy, and angular deformation at yield and failure were recorded and analyzed by using repeated measures ANOVA. Results Mean time ± SD to complete the construct was 2.2 ± 0.8 and 2.3 ± 0.6 minutes for warm and cold water, respectively. Warm water and longer cure times produced constructs with greater stiffness (23.05 vs 20.88 newton-meter degrees [Nm°] at 0.5 hours), bending moment (121.75 vs 107.31 Nm° at 0.5 hours), and cumulative energy (557.33 vs 428.89 Nm° at 1 hour) at yield and failure. Longer cure time significantly increased angular deformation of rods at failure; however, water temperature did not. In general, the strongest casts were produced with warm water and after curing for 24 hours. Conclusion Fiberglass casts continued to gain strength for at least 24 hours. Use of warm water increased the rate of curing, resulting in stronger constructs at earlier time points. Clinical significance Use of warm water is recommended to initiate fiberglass cast curing, especially if the casted limb will be loaded soon after cast application.

Summary Gastrointestinal rupture is an important cause and complication of equine colic. The stomach is the most commonly affected segment in the gastrointestinal tract involved in gastrointestinal rupture. Gastric rupture can be primary or secondary; however, unless prodromal clinical signs are identified, localised and corrected, the resulting peritoneal contamination with feed, intestinal secretions and bacteria is invariably fatal. Causes for gastric rupture may be known or idiopathic; however, factors that predispose a horse to gastric rupture are poorly understood. Further research is needed to identify underlying causes and pathophysiology of gastric rupture to prevent it from occurring.

Tetrabromobisphenol A (TBBPA) is a ubiquitous flame retardant. A high-throughput immunoassay would allow for monitoring of human and environmental exposures as a part of risk assessment. Naturally occurring antibodies in camelids that are devoid of light chain, show great promise as an efficient tool in monitoring environmental contaminants, but they have been rarely used for small molecules. An alpaca was immunized with a TBBPA hapten coupled to thyroglobulin and a variable domain of heavy chain antibody (VHH) T3-15 highly selective for TBBPA was isolated from a phage displayed VHH library using heterologous coating antigens. Compared to the VHHs isolated using homologous antigens, VHH T3-15 had about a 10-fold improvement in sensitivity in an immunoassay. This assay, under the optimized conditions of 10% methanol in the assay buffer (pH 7.4), had an IC50for TBBPA of 0.40 ng mL-1and negligible cross reactivity (

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 cm2 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

Objective To investigate postoperative hemoperitoneum in a population of horses that had surgery for colic. Study design Retrospective case series. Animals Horses (n = 23). Methods Preoperative, intraoperative, and postoperative information was obtained from medical records (1985–2012) of horses with postoperative hemoperitoneum after emergency exploratory celiotomy. Pre-existing hemoperitoneum during surgery and nonsurgical hemoperitoneum were excluded. Results Of 4520 horses that had emergency exploratory celiotomy for gastrointestinal disease, 23 horses met inclusion criteria; an incidence of 0.5%. Horse signalment approximated the colic population, although Thoroughbreds were significantly overrepresented. Hemoperitoneum was significantly associated with intestinal resection. Postoperative hemoperitoneum was recognized a mean (±SD) of 1.0 ± 0.7 days after surgery and associated with tachycardia, decreasing hematocrit, incisional drainage, or ultrasonographic identification of swirling, echogenic abdominal fluid. Primary treatments included intravenous fluid therapy (n = 23), colloid support (20), blood transfusion (13), and antifibrinolytic agents (11). Fifteen horses (65%) survived to discharge, which was associated with admission lactate and days of hospitalization. Conclusions Postoperative hemoperitoneum is a rare complication of exploratory celiotomy in horses that should be considered when there are signs of abdominal discomfort and declining hematocrit in the early postoperative period. Prognosis is guarded because of potential sequelae of septic peritonitis and adhesion formation.

Objective To compare 3 portable handheld analyzers with a bench top blood gas analyzer for measurement of blood and peritoneal fluid L-lactate concentrations in horses admitted with signs of colic. Study Design Prospective clinical study. Sample Population Blood and peritoneal fluid from horses with colic. Methods L-lactate concentrations in heparinized blood and peritoneal fluid were measured serially on 10 occasions to evaluate repeatability of the portable analyzers. Blood and peritoneal fluid L-lactate concentrations were simultaneously evaluated by a bench top and 3 portable analyzers and the results compared by intraclass correlation coefficients and Bland Altman plots. L-Lactate concentrations in a subgroup of peritoneal fluid samples were evaluated by a chromogenic laboratory assay and compared with the bench top and the handheld analyzers. Results Portable lactate analyzers had good intra-analyzer reliability for peritoneal fluid. Two portable analyzers had poor intra-analyzer reliability for mid concentrations of L-lactate in blood. L-lactate measurements from portable analyzers were closer to the bench top analyzer at low concentrations of L-lactate than at higher concentrations. Compared with the bench top analyzer, the Lactate Pro and Lactate Plus have the highest intraclass correlation coefficient and the smallest bias for peritoneal fluid and blood L-lactate, respectively. The bench top analyzer and the Lactate Pro had the highest level of agreement for peritoneal fluid compared with the chromogenic assay. Conclusions Although portable analyzers are alternatives for the measurement of L-lactate concentration in field situations, clinicians need to be aware of the variable results between analyzers, especially when extrapolating means or cutoff values from studies using different lactate analyzers.

An antibody-based analytical method for the detection of a chemical flame retardant using antibody fragments isolated from an alpaca has been developed. One specific chemical flame retardant congener, 2,2′,4,4′- tetrabrominated diphenyl ether (BDE-47), is often the major poly-BDE (PBDE) congener present in human and environmental samples and that which is the most frequently detected. An alpaca was immunized with a surrogate of BDE-47 covalently attached to a carrier protein. The resulting mRNA coding for the variable domain of heavy-chain antibodies (VHH) were isolated, transcribed to cDNA, and cloned into a phagemid vector for phage display library construction. Selection of VHHs recognizing BDE-47 was achieved by panning under carefully modified conditions. The assay sensitivity for detecting BDE-47 was down to the part-per-billion (microgram per liter) level. Cross-reactivity analyses confirmed that this method was highly selective for BDE-47 and selected hydroxylated metabolites. When exposed to elevated temperatures, the camelid VHH antibodies retained more reactivity than a polyclonal antibody developed to the same target analyte. The use of this VHH antibody reagent immobilized onto a Au electrode for impedance biosensing demonstrates the increased versatility of VHH antibodies. © 2014 American Chemical Society.

Anti-idiotypic antibodies recognize the antigenic determinants of an antibody, thus they can be used as surrogate antigens. Single-domain antibodies from camlid heavy-chain antibodies with the benefit features of small size, thermostability, and ease in expression, are leading candidates to produce anti-idiotypic antibodies. In this work, we constructed an antibody phage library from the mRNA of an alpaca immunized with an antiaflatoxin monoclonal antibody (mAb) 1C11. Three anti-idiotypic VHH antibodies were isolated and applied to immunoassay toward aflatoxin as a coating antigen. The best immunoassay developed with one of these VHH antibodies shows an IC50 of 0.16 ng/mL toward aflatoxin B1 and cross-reactivity toward aflatoxin B2, G1, and G2 of 90.4%, 54.4%, and 37.7%, respectively. The VHH-based immunoassay was successfully applied to the analysis of peanuts, corn, and rice, which are the predominant commodities regularly contaminated by aflatoxins. A good correlation (r(2) = 0.89) was found between the data obtained from the conventional ELISA and the ELISA based on a VHH coating antigen for the analysis of aflatoxins in peanuts and feedstuff. The use of biotechnology in developing the surrogate, the absence of standard aflatoxin and organic solvents in the synthesis procedures, and the reproducibility of the VHH antibody makes it an ideal strategy for replacing conventional synthesized antigens.

Summary This case report describes retroperitoneal and subserosal emphysema as the primary indication of a caecal perforation associated with an episode of colic. Feed contamination was not noted on repeated peritoneal fluid samples or within the peritoneal cavity at the time of surgery; however, subserosal and retroperitoneal emphysema at the base of the caecum was identified during surgical exploration, which later corresponded to retroperitoneal caecal perforation at necropsy examination.

OBJECTIVE To compare clinical findings and short-term outcome for horses with intestinal entrapment in the gastrosplenic ligament (GLE) with those of horses with intestinal entrapment in the epiploic foramen (EFE). DESIGN Retrospective case-control study. ANIMALS 43 horses with GLE (cases) and 73 horses with EFE (controls). PROCEDURES Medical records of horses examined because of colic at a veterinary teaching hospital between 1992 and 2012 were reviewed. Signalment was extracted from medical records for all horses with colic (colic population), and additional information regarding colic history, clinical findings, treatments, and outcome was extracted from the records of horses in which GLE or EFE was diagnosed during surgery or necropsy. Signalment was compared between the colic population and the case and control populations. Clinical findings and short-term outcome were compared between the cases and controls. RESULTS The proportions of middle-aged horses and geldings in both the case and control groups were greater than those in the colic population. Mean heart rate and blood and peritoneal fluid lactate concentrations in horses with EFE were significantly greater than those for horses with GLE. The proportion of horses that underwent surgery and were discharged from the hospital (short-term survival rate) did not differ between the GLE (22/25 [88%]) and EFE (29/34 [85%]) groups. CONCLUSIONS AND CLINICAL RELEVANCE Compared with the colic population, results suggested middle-aged geldings might be predisposed to GLE and EFE. The short-term survival rate was similar between the GLE and EFE groups even though horses with EFE had more severe systemic derangements than did horses with GLE.

To determine the influence of radiographic quantification of sand accumulation on the medical versus surgical management of large colon sand accumulations. To compare short- and long-term outcomes and complications associated with medical and surgical management of these horses.Retrospective.A total of 153 horses.Medical records and abdominal radiographs of horses presented for colic between 2004 and 2014 were reviewed. Severity of sand accumulation was quantified by tracing and measuring a region of interest with a commercial software program. Breed, weight, amount of sand, presence of diarrhea at presentation, treatment, and the development of complications were recorded.Records from 153 horses were reviewed. The mean cross-sectional area of sand accumulation was 692.9 cmIncreased accumulation of gas on radiographs and transrectal palpation of impaction or intestinal gas distension increase the likelihood of surgery. Both medical and surgical treatments carry a good prognosis.The sheer quantity of sand is not a factor when determining surgical intervention. Attention should be paid to the presence of increased gas accumulation on rectal or radiographic examination.

Six adult male alpacas received one subcutaneous administration of ceftiofur crystalline free acid (CCFA) at a dosage of 6.6 mg/kg. After a washout period, the same alpacas received three subcutaneous doses of 6.6 mg/kg CCFA at 5-day intervals. Blood samples collected from the jugular vein before and at multiple time points after each CCFA administration were assayed for ceftiofur- and desfuroylceftiofur-related metabolite concentrations using high-performance liquid chromatography. Pharmacokinetic disposition of CCFA was analyzed by a noncompartmental approach. Mean pharmacokinetic parameters (± SD) following single-dose administration of CCFA were Cmax (2.7 ± 0.9 μg/mL); Tmax (36 ± 0 h); area under the curve AUC0→∞ (199.2 ± 42.1 μg·h/mL); terminal phase rate constant λz (0.02 ± 0.003/h); and terminal phase rate constant half-life t1/2λz (44.7 h; harmonic). Mean terminal pharmacokinetic parameters (±SD) following three administrations of CCFA were Cmax (2.0 ± 0.4 μg/mL); Tmax (17.3 ± 16.3 h); AUC0→∞ (216.8 ± 84.5 μg·h/mL); λz (0.01 ± 0.003/h); and t1/2λz (65.9 h; harmonic). The terminal phase rate constant and the Tmax were significantly different between single and multiple administrations. Local reactions were noted in two alpacas following multiple CCFA administrations.

Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain (VHH). Although conventional antibodies dominate current assay development, recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. We expressed VHHs from an immunized alpaca and developed a VHH-based immunoassay using 3-phenoxybenzoic acid (3-PBA), a major metabolite of pyrethroid insecticides as a model system. A phage VHH library was constructed, and seven VHH clones were selected by competitive binding with 3-PBA. The best immunoassay developed with one of these VHHs showed an IC50 of 1.4 ng/mL (limit of detection (LOD) = 0.1 ng/mL). These parameters were further improved by using the phage borne VHH, IC50 = 0.1 ng/mL and LOD = 0.01 ng/mL. Both assays showed a similar tolerance to methanol and dimethylsulfoxide up to 50% in assay buffer. The assay was highly specific to 3-PBA and its ...

Summary Reasons for performing study: Colic is a common reason for elimination from equine endurance competitions and has recently been identified as the leading cause of mortality in this group of horses. Hydration and electrolyte derangements are often severe, but are probably related to endurance exercise and not necessarily the episode of colic. Better understanding of the causes of colic and the expected outcome is needed to guide treatment decisions in endurance horses. Objectives: To describe the history, case details, clinical examination, laboratory, treatment and outcomes for horses presenting to equine referral centres for treatment of colic associated with endurance competition and to identify variables associated with prolonged hospitalisation. Methods: Thirty-six horses from 2 equine referral centres were included in the analysis. In addition to descriptive statistics, Cox proportional hazards models were used to evaluate factors associated with length of hospitalisation. Results: A diagnosis of open or ileus was made in the majority of horses (56%). Salmonellosis and enteritis (Salmonella negative) were also recognised (16%). Exploratory abdominal surgery was performed in 5 of the horses. Only one of 36 horses did not survive to discharge. Previous eliminations from competition (negative association) and total i.v. fluids within the first 24 h (positive association) of admission were both associated with length of hospitalisation. Conclusions: Endurance horses with colic typically respond to medical treatment but in some cases hospitalisation may be prolonged. The role of Salmonella infections in endurance horses with colic requires further research. Potential relevance: Despite potentially severe clinical and laboratory derangements, equine practitioners should make owners aware that the prognosis for competing endurance horses with colic is good when treated appropriately.

Objective—To determine the outcome of penetrating injuries to the central region of the foot in equids and identify factors that may affect treatment and outcome. Design—Retrospective case series. Animals—63 equids (61 horses, 1 pony, and 1 mule). Procedures—Records of equids incurring puncture wounds through the frog (cuneus ungulae) or collateral sulci of the foot between 1998 and 2008 were reviewed. Evaluated factors that were hypothesized to affect outcome included signalment, degree of lameness, foot affected, duration between injury and admission, and treatment. Injuries were graded from 1 (< 1 inch; involving superficial corium only) to 4 (involving a synovial structure) on the basis of severity of penetration as determined by radiographic evidence or findings on synoviocentesis at the time of admission. Results—Overall, 60% (38/63) of equids returned to soundness. Thirteen equids were euthanized on the basis of synovial structure involvement and financial constraints. Of 35 equids that were treated conservatively, which may have included undergoing a surgical procedure with the horse standing, 32 (91.4%) returned to their previous level of soundness. Fifteen equids underwent surgical treatment under general anesthesia, of which 6 (40%) became sound for intended use. Ten of 34 (29%) equids with synovial structure involvement regained soundness. Equids treated earlier after injury had a better prognosis. Equids with a hind foot injury had a more favorable outcome than those with a forefoot injury. Conclusions and Clinical Relevance—Results suggested that penetrating injuries located centrally in the foot of equids without involvement of a synovial structure have a favorable prognosis, especially if managed early. Penetration of a synovial structure provided a poor prognosis.

OBJECTIVE To determine whether in healthy horses and those with colic, exposure of peritoneal fluid to room air affects values obtained on biochemical analysis. STUDY DESIGN Prospective study. ANIMALS Adult horses with a primary complaint of acute abdominal pain (n=29) and 12 healthy horses. METHODS Peritoneal fluid was aseptically collected under aerobic and anaerobic conditions. After collection, pH, PCO(2) , PO(2) , HCO(3) (-) , Na(+) , ionized Ca(2+) , K(+) , lactate, and glucose were immediately measured using a commercial blood gas analyzer. Biochemical variables were compared between aerobically and anaerobically obtained samples using a paired t-test. RESULTS In healthy horses, peritoneal fluid samples collected under anaerobic conditions had higher PCO(2) and ionized Ca(2+) and lower PO(2) , HCO(3) (-) , and pH compared with samples exposed to air. No differences were observed for K(+) , Na(+) , glucose, and lactate. In horses with colic, samples collected anaerobically had higher PCO(2) , ionized Ca(2+) , Na(+) , and glucose and lower PO(2) , HCO(3) (-) , and pH value compared with samples exposed to air. No differences were observed for K(+) and lactate. CONCLUSION Exposure of peritoneal fluid to room air had a significant effect on pH, PCO(2) , PO(2) , and variables associated or dependent on changes in pH such as HCO(3) (-) and ionized Ca(2+) . Interpretation of biochemical analysis of peritoneal fluid may be influenced by sample collection method.

Summary Reasons for performing study: Osteoarthritis is a frequent sequela of joint disease, especially with severe injuries or if attempts at therapy are unsuccessful. Negative and positive effects of corticosteroid treatment of articular cartilage have been demonstrated by in vitro and in vivo studies. Objectives: To assess the metabolic effects of varying dosages of methylprednisolone acetate (MPA) and triamcinolone acetonide (TA) on interleukin-1α (IL-1) conditioned equine cartilage explants. Our hypothesis was that lower dosages of corticosteroids would be less detrimental to cartilage metabolism than higher dosages. TA would be less detrimental to cartilage metabolism than MPA. Methods: Treatment groups included articular cartilage explants with no IL-1 (control), IL-1 alone, and IL-1 plus 10, 5, 1 and 0.5 mg/ml MPA or 1.2, 0.6, 0.12 and 0.06 mg/ml TA. Explants were labelled with 35SO4 priorto the beginning and end of the experiment to assess glycosaminoglycan (GAG) degradation and synthesis, respectively. Total GAG content in media and explants and total cartilage DNA were also analysed. Results: MPA and TA reduced GAG synthesis compared to control and IL-1 alone. The highest dosage of MPA (10 mg/ml) reduced GAG synthesis less than lower dosages of MPA and all dosages of TA Compared to IL-1 alone, all dosages of TA and lower dosages of MPA increased GAG degradation. MPA at 10 mg/ml reduced GAG degradation. Both MPA and TA increased media GAG content compared to control and IL-1 explants. Total cartilage GAGs were unchanged with MPA, but reduced with TA, compared with IL-1 alone. Total cartilage DNA was decreased with MPA and increased with TA compared to IL-1 and control explants. Conclusions: MPA and TA did not counteract the negative effects of IL-1 and did not maintain cartilage metabolism at control levels. Lower dosages of MPA and TA were not less detrimental to cartilage metabolism than higher dosages. TA did not appear to be less harmful than MPA on cartilage metabolism. The results of this study differ from the findings of comparable in vivo studies. Potential relevance: The low numbers of horses used in this study limits extrapolation of these findings to the equine population; however, this study also questions the clinical relevance of this in vitro model.

Summary Reasons for performing study: Clinical trials in human and veterinary literature have documented the benefits of oral nutraceutical joint supplements containing glucosamine (GU) and chondroitin sulphate (CS) to treat mild to moderate osteoarthritis, but the effects of these components have not yet been conclusively determined. Objectives: To assess varying dosages of GU and CS on normal and interleukin-1α (IL-1) conditioned equine cartilage explants and rationalise the use of these products. Hypothesis: Treatment would not be detrimental to cartilage metabolism and higher dosages and the combination of GU and CS would be more beneficial than lower dosages and GU or CS alone. Methods: Articular cartilage explants collected from the femoral trochlea and condyles were cultured in normal and IL-1 conditioned media. Treatment groups included 0, 12.5, 25, 125 and 250 μg/ml concentrations of GU alone, CS alone, or GU+CS in combination. Glycosaminoglycan (GAG) synthesis and total GAG content in the explants and media were analysed. Results: There were no detrimental effects of GU, CS or GU+CS on cartilage metabolism. High dosages of GU+CS reduced total GAG release into the media (degradation). Conclusions: Our results suggests that GU+CS may prevent cartilage GAG degradation. Potential relevance: The combination of GU and CS may be more effective in preventing or treating osteoarthritis in horses than either product alone.

A 6-year-old Quarter Horse stallion was referred to Oklahoma State University Veterinary Medical Teaching Hospital for evaluation of abdominal pain that developed after breeding activity earlier in the day. The horse developed diarrhea and progressively worsening neurologic signs (circling, ataxia, head pressing) within 22 hours of presentation and was subsequently euthanized due to severe self-destructive behavior. Antemortem biochemical and hematologic abnormalities included hypocalcemia but no evidence of hepatic disease. Idiopathic hyperammonemia and encephalopathy were suspected; cerebrospinal fluid (CSF) and aqueous humor were collected 10 hours postmortem for ammonia analysis using a colorimetric assay. Results were compared with those of 6 horses that also had been euthanized, for diseases unrelated to encephalopathy. Ammonia also was measured in plasma samples obtained antemortem. Ammonia concentrations in plasma (958 micromol/L), CSF (1566 micromol/L) and aqueous humor (1018 micromol/L) samples from the stallion were markedly increased compared to those in the 6 unaffected horses (plasma, 9-43 micromol/L; CSF, 370-532 micromol/L; aqueous humor, 70-483 micromol/L). Since the acute nature of hyperammonemic encephalopathy often does not provide sufficient time for an antemortem diagnosis, postmortem analysis of CSF and aqueous humor ammonia concentrations may be a useful alternative for documenting hyperammonemia in horses.

A 523 kg Quarter Horse was anesthetized for unilateral eye enucleation. The anesthetic period was unremarkable. During anesthetic recovery the cap on the jugular venous catheter became dislodged. Clinical signs of pulmonary edema associated with moderate arterial hypoxemia subsequently developed. Although pulmonary edema resolved with medical therapy, the day following anesthetic recovery, clinical signs of vestibular disease and blindness developed. Treatment included nasal oxygen insufflation, flunixin meglumine, furosemide, dexamethasone, thiamine, dimethylsulfoxide, antimicrobials, and phenylbutazone. The horse recovered and was discharged from the hospital after 7 days of treatment and was neurologically normal at 6 weeks. While venous air embolism was not confirmed in this case, the catheter cap complication followed by signs of pulmonary edema and neurologic sequelae support the presumptive pathogenesis of this horse's complications. Diagnostic confirmation of air embolism in horses with compatible acute clinical signs should be documented with echocardiography.

The purpose of this retrospective case-control study was to identify factors associated with primary gastric rupture and to investigate if there were differences between etiologies of primary gastric rupture. Compared to the general colic population, Quarter horses were under-represented and Friesians and draft breeds were over-represented in 47 cases of primary gastric ruptures. Horses with primary gastric rupture typically presented with severe clinical and clinicopathological derangements. There were 24 idiopathic gastric ruptures, 20 gastric impaction associated ruptures, and 3 perforating gastric ulcers. Thoroughbred horses were over-represented in the idiopathic gastric rupture group compared to other breeds and etiologies. This study suggests the presence of important breed predispositions for development of gastric rupture. Further study is necessary to identify if these predispositions are associated with management factors or breed-specific disorders.