A multicenter retrospective case-cohort study on the prevalence of incisional morbidities in late pregnant mares following exploratory celiotomy (2014-2019): 579 cases.

OBJECTIVE: To report the prevalence and risk factors for incisional morbidities in late pregnant and nonpregnant/early pregnant control mares following colic surgery. DESIGN: Multicenter, retrospective, cohort study from January 2014 to December 2019. SETTING: Two university teaching hospitals and 1 private referral center. ANIMALS: Five hundred and seventy-nine fillies and mares ≥2 years old that underwent celiotomy. Pregnant mares (n = 54) were >240 days in gestation from the last known breeding date and were compared to control females (n = 525) undergoing colic surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Morbidity rates were not different between mare groups with 56% of pregnant mares and 51% of control mares reporting at least 1 morbidity. Incisional swelling was the most common reported complication in both groups. Incisional swelling was associated with shorter hospital stays (odds ratio [OR], 0.18; P < 0.01), and drainage was associated with a longer hospital stay (OR, 1.27; P ≤ 0.01) and with use of an abdominal bandage (OR, 4.4; P < 0.01). Herniation was associated with hypercapnia under anesthesia (OR, 1.1; P = 0.048), previous abdominal surgery (OR, 8.3; P = 0.003), and with use of an abdominal bandage (OR, 56; P = 0.006). Body wall dehiscence was associated with longer hospital stay (OR, 1.2; P < 0.01). Nonsurvival was higher in pregnant mares (13%) compared to control mares (5%; P = 0.02). CONCLUSIONS: The prevalence of incisional morbidities did not differ between pregnant and control mares undergoing colic surgery. Several factors were associated with incisional morbidities, including the duration of surgery and anesthesia, anesthetic variables, abdominal bandage use, previous ventral abdominal incision, and longer duration of hospitalization.

Prognosis for survival to discharge and racing performance in Thoroughbred foals treated for single joint septic arthritis (2009-2016).

BACKGROUND: Haematogenous septic arthritis is a major cause of morbidity and mortality in foals. Previous research has demonstrated a variable prognosis for athletic performance in foals diagnosed with septic arthritis. OBJECTIVE: To determine the racing prognosis for Thoroughbred foals, 6 months of age or less with single septic joint of presumed haematogenous origin without recognised systemic sepsis or other serious comorbidity compared with a group of maternal sibling controls. STUDY DESIGN: Retrospective cohort study. METHODS: Data were collected from Rood and Riddle Equine Hospital in-patient records from 2009 to 2016. Parameters evaluated included: diagnostic tests, therapeutic regimens, final diagnosis and outcome. Racing records were obtained from a public archive for cases and two maternal siblings. Univariable analyses of categorical variables were conducted. RESULTS: Ninety-five cases of Thoroughbred foals 6 months of age or less were included in this study. The last measured synovial cell count prior to hospital discharge or euthanasia (OR 0.5, p value 0.002, 95% CI: 0.3-0.8) was an indicator of poor prognosis for survival to discharge. Overall, the prognosis for survival was high (93%). Total winnings per career were the only statistically significant racing performance variable between cases and paired controls (IRR 0.7, p value, 0.05, 95% CI: 0.5-0.99). MAIN LIMITATIONS: Retrospective study, evaluation of one regional population, potential for unknown prior exclusionary treatment on farm, unknown chronicity, no data on acute phase proteins and proportion of neutrophils of synovial fluid and unknown medical records of controls. CONCLUSIONS: While total winnings were reduced compared with maternal siblings, Thoroughbred foals with single joint septic arthritis have a favourable prognosis for both survival and starting in a race.

CONTEXTO: Artrite séptica hematogênica é a maior causa de morbidade e mortalidade em potros. Estudos prévios demonstraram um prognóstico variável para a performance atlética de potros diagnosticados com artrite séptica. OBJETIVOS: Determinar o prognóstico atlético de potros Puro Sangue Inglês, de seis meses de idade ou menos, com uma única articulação séptica de origem presumida hematogênica, sem nenhum sinal sistêmico de sepse reconhecido e sem outras comorbidades sérias, comparados com um grupo de irmãos maternos como controle. DELINEAMENTO DO ESTUDO: Estudo coort retrospectivo. MÉTODOS: Dados foram coletados de pacientes do Rood and Riddle Equine Hospital de 2009 a 2016. Os parâmetros avaliados incluíram: testes diagnósticos, tratamentos, diagnóstico final e sobrevivência à alta hospitalar. Os dados das corridas foram obtidos do equibase.com para os casos clínicos e dois irmãos maternos. Análise univariável de variantes categóricas foi realizada. RESULTADOS: Noventa e cinco potros Puro Sangue Inglês de seis meses de idade ou menos foram incluídos nesse estudo. A última mensuração da contagem de células no líquido sinovial antes da alta hospitalar ou eutanásia (OR 0.5, p-value 0.002, 95% CI: 0.3 a 0.8) foi um indicador estatisticamente significante de prognóstico ruim para sobrevivência. O prognóstico para sobrevivência foi alto (93%). O ganho total por carreira foi o único fator estatisticamente diferente entre casos e controles (IRR 0.7, p-value, 0.05, 95% CI: 0.5 a 0.99). PRINCIPAIS LIMITAÇÕES: Estudo retrospectivo, avaliação de uma população em uma única região, chances de um tratamento desconhecido na fazenda, cronicidade desconhecida, ausência de resultados de proteínas de fase aguda e concentração de neutrófilos no líquido sinovial, e ausência de controles dos registros médicos. CONCLUSÕES: Apesar do ganho total ser menor quando comparado com os irmãos maternos, potros Puro Sangue Inglês com uma única articulação séptica têm um prognóstico favorável para sobrevivência e para iniciar uma corrida.

Preoperative computed tomographic evaluation of neonatal foals with rib fractures.

OBJECTIVE: To compare ultrasonographic and computed tomographic findings in neonatal foals prior to surgical repair of rib fractures as well as postoperative outcomes in foals with and without preoperative thoracic computed tomography (CT). Study design Retrospective cohort study. Sample population 43 neonatal foals undergoing surgical treatment of rib fractures between 2013 and 2021. METHODS: Medical records were reviewed for age, sex, delivery method, comorbidities, presurgical anesthetic time, surgical time, number and location of fractured ribs identified with ultrasound and CT, number and location of ribs surgically repaired, survival to discharge, and post-mortem findings. Statistical analyses were performed using chi-square, Fisher's exact, and t-tests. RESULTS: Twenty-two foals underwent surgical repair of rib fractures after preoperative CT from 2019-2021 (median: 4/18/20) and 21 foals were anesthetized (20 underwent repair) for surgical repair of rib fractures without preoperative CT from 2013-2020 (median: 4/9/15). Ultrasound and CT findings differed in number and location of fractured ribs in 13/17 (76%) foals (p = .049). More cranially positioned ribs were identified as fractured with CT than with ultrasonography (p = .035). Survival to discharge was improved when foals underwent CT (20/22, 91%) than when they did not (12/20, 60%, p = .019). CONCLUSION: Ultrasound findings differed from CT findings in most foals. Foals evaluated with CT were more likely to survive to hospital discharge. CLINICAL SIGNIFICANCE: When available, CT is recommended prior to surgical repair of rib fractures in neonatal foals.

Clinical outcomes after colopexy through left ventral paramedian incision in 156 thoroughbred broodmares with large colon disorders (1999-2015).

OBJECTIVE: To describe a technique for colopexy via a left ventral paramedian incision and report postoperative clinical outcomes. STUDY DESIGN: Retrospective case series. ANIMALS: One hundred fifty-six thoroughbred broodmares treated with a colopexy through a left ventral paramedian incision between 1999 and 2015. METHODS: Medical records were reviewed for postoperative complications and survival to discharge. The survival rate at 1 year after surgery was based on the medical record, progeny record, or client telephone conversation. Progeny records were reviewed to assess reproductive performance. T tests, χ2 tests, logistic regression, and Kaplan-Meier survival curves were used to identify prognostic factors. RESULTS: The rates of postoperative recurrence of large colon volvulus and colon rupture were 1.2% and 3%, respectively. Ninety-three percent of mares that were treated were discharged alive from the hospital, and 78% were alive 1 year after surgery. The diagnosis of 1 of the following complications increased the risk of death within 1 year: systemic inflammatory response syndrome (SIRS), diarrhea, and/or thrombophlebitis (odds ratio [OR] 4.76). Sixty-six percent of mares that were pregnant at the time of colopexy and discharged alive from the hospital produced a live foal. The percentage of live foals produced each year that the mare was bred after colopexy was 67%. CONCLUSION: Thoroughbred mares treated with colopexy via a left paramedian incision had a good prognosis for survival and continued use as a broodmare. SIRS, diarrhea, or jugular thrombophlebitis affected long-term survival in this population. CLINICAL SIGNIFICANCE: Colopexy via a left paramedian incision is a suitable alternative to colopexies requiring a second incision or creating adhesions between the colon and the linea alba in thoroughbred mares.

Effects of hyaluronate-carboxymethylcellulose membranes on the clinical outcome of horses undergoing emergency exploratory celiotomy.

OBJECTIVE: To determine the influence of hyaluronate-carboxymethylcellulose (HA-CMC) membranes applied to intestinal anastomoses or enterotomies on postoperative complications after emergency exploratory celiotomy. STUDY DESIGN: Multicenter retrospective case-controlled series. ANIMALS: Adult horses (59 in the HA-CMC group and 91 controls). METHODS: Medical records from 4 referral hospitals were searched for horses ≥1 year of age, treated between 2008 and 2014 with emergency exploratory celiotomy, and surviving at least 24 hours postoperatively. Horses receiving repeat celiotomy during the same hospitalization were excluded. Horses who received HA-CMC were matched with controls who did not receive HA-CMC but had similar intestinal lesions and procedures at the same referral hospital. Postoperative complications (colic, nasogastric reflux, fever, incisional infection, and septic peritonitis), duration of hospitalization, and survival were compared between groups. Data were compared between horses by t test, Wilcoxon signed rank test, and χ2 test. RESULTS: The volume of nasogastric reflux at admission (P = .02) and the duration of administration of lidocaine after surgery (P = .02) were greater in horses with HA-CMC membranes than in controls. No difference in postoperative complications or survival was detected between groups: 48 of 59 (81%) horses treated with HA-CMC survived until discharge from the hospital compared with 80 of 91 (88%) horses in the control group (P = .27). Fifteen of 21 horses treated with HA-CMC and 30 of 43 horses in the control group survived >12 months after hospital discharge. CONCLUSION: Application of HA-CMC membranes to anastomoses or intestinal incisions did not influence postoperative complications or survival after emergency celiotomy compared with controls. CLINICAL SIGNIFICANCE: The safety and efficacy of HA-CMC membrane application to intestinal sites during colic surgery in horses is equivocal.

Update on laryngeal disorders and treatment.

Laryngeal disorders are relatively common in the horse, and thorough diagnostic evaluation is essential to make an accurate definitive diagnosis and selection of appropriate treatment. The value of exercising endoscopy must not be overlooked, and the recent development of dynamic (overground) endoscopy is providing new insights into dynamic laryngeal lesions. The focus of this article will be on recently described disorders and treatments or modifications to existing treatments. It summarizes the numerous investigations attempting to perfect the laryngoplasty procedure for treatment of laryngeal hemiplegia. The newly described conditions, bilateral dynamic laryngeal collapse, and dynamically flaccid epiglottis will also be discussed.

Evaluation of survival rate and athletic ability after nonsurgical or surgical treatment of cleft palate in horses: 55 cases (1986-2008).

OBJECTIVE: To determine survival rate and athletic ability after nonsurgical or surgical treatment of cleft palate in horses. DESIGN: Retrospective case series. ANIMALS: 55 horses with cleft palate. PROCEDURES: 13 of the 55 horses died or were euthanized without treatment and were not included in all analyses. Medical records were reviewed for signalment, history, method of diagnosis, soft or hard palate involvement, type of surgical procedure performed, postoperative complications, and survival to hospital discharge. Information on athletic ability was acquired from race records and follow-up conversations with owners, trainers, or referring veterinarians. RESULTS: The predominant reason for initial evaluation was milk or feed in the nostrils (60%). The diagnosis was confirmed by means of videoendoscopy of the upper portion of the airway in all cases. Most cases involved the soft palate only (92.7%). Twenty-six of the 55 (47.3%) horses underwent surgical repair, and 12 of these had dehiscence at the caudal edge of the soft palate. Among potential racehorses, 14 of 33 had surgery. Of these, 12 of 14 survived to discharge and 2 horses raced. Among potential racehorses, 10 of 33 were discharged without surgery and 2 of these raced. Among nonracehorses, 12 of 22 underwent surgery and 11 survived to discharge. All horses that were discharged and for which follow-up information was available survived to 2 years of age or older without ill thrift despite dehiscence at the caudal edge of the soft palate and continued mild nasal discharge. CONCLUSIONS AND CLINICAL RELEVANCE: Horses with cleft palate had a higher survival rate than previously reported.

Imaging diagnosis--nasal septal and laryngeal cyst-like malformationsin a Thoroughbred weanling colt diagnosed using ultrasonography and magnetic resonance imaging.

A foal was examined for abnormal upper airway noise. Endoscopically, there were narrowed nasal passages and an extralumenal mass of the cranial trachea. Using ultrasonography and magnetic resonance (MR) imaging of the larynx and cranial cervical trachea, irregular margins of the laryngeal cartilages and first tracheal ring containing areas consistent with fluid were identified. In MR images, a widened nasal septum was seen that contained material consistent with fluid. Postmortem examination confirmed the diagnosis of nasal septal, laryngeal, and cranial cervical tracheal cyst-like lesions. This is a unique congenital condition, in which premortem imaging was instrumental in defining the abnormalities.

A comparison of laryngoplasty and modified partial arytenoidectomy as treatments for laryngeal hemiplegia in exercising horses.

OBJECTIVE: To compare upper airway mechanics, arterial blood gases, and tracheal contamination in horses with induced left laryngeal hemiplegia (recurrent laryngeal neuropathy [RLN]) treated by laryngoplasty/vocal cordectomy (LPVC) or modified partial arytenoidectomy (MPA). STUDY DESIGN: Repeated measures under the following conditions: Control, RLN, LPVC, and MPA. ANIMALS: Six horses. METHODS: Two trials were conducted under all conditions at 80% and 100% of maximal heart rate (HR(max)). In Trial 1, arterial blood gases, tracheal and pharyngeal pressures, and laryngeal videoendoscopy were recorded. In Trial 2, upper airway pressure and airflow were determined. Tracheobronchial aspirates were performed after exercise to quantify airway contamination. RESULTS: Compared with control, RLN significantly increased inspiratory impedance and worsened exercise-induced hypoxemia. At 80% HR(max), LPVC restored most variables to control values. At 100% HR(max), LPVC improved all variables, but did not restore minute volume, arterial pH, and PaCO(2). At 80% HR(max), MPA restored all variables except bicarbonate to control values. At 100% HR(max), MPA improved all variables, but did not statistically restore minute ventilation or bicarbonate level. Only minor differences were noted between LPVC and MPA. Both resulted in equivalent tracheal contamination. CONCLUSIONS: Airway mechanics and arterial blood gas values were not restored to normal after either LPVC or MPA in horses exercising at HR(max). This does not affect ventilation at sub-maximal exercise, but has clinical implications at HR(max). Both procedures diminish normal laryngeal protective mechanisms. CLINICAL RELEVANCE: At sub-maximal exercise intensities both LPVC and MPA restore airway ventilation to normal. At maximal exercise the superiority of LPVC over MPA is slight.

Acid-base, blood gas, and physiologic parameters during laparoscopy in the head-down position in white-tailed deer (Odocoileus virginianus).

The objective of this project was to evaluate the acid-base, blood gas, and physiologic parameters of white-tailed deer (Odocoileus virginianus) during laparoscopy in the head-down position. Eleven white-tailed does were captured and then immobilized with xylazine (6 mg/kg i.m.) and ketamine (7 mg/kg i.m.). The deer were intubated orotracheally and maintained with isoflurane in oxygen. The deer were positioned in dorsal recumbency and positive pressure ventilated. Heart rate (HR), arterial blood pressure, end-tidal carbon dioxide concentration (FE/CO2), and CO2 insufflation pressure were recorded every 5 min. Respiratory parameters, plasma electrolytes, and peak inspiratory pressure were measured immediately before tilting deer in the head-down position (45-55 degrees), 5 min after tilting, and immediately before the end of the procedure (while tilted). Butorphanol (0.05 mg/kg i.m.) was administered at the end of the procedure and yohimbine (0.2 mg/kg i.v.) administered before release. The deer weighed 52 kg (28-70 kg) [median (minimum-maximum)]. The peak inspiratory pressure in dorsal recumbency while still horizontal was 25 cm H2O (16-28 cm H2O), which increased to 29 cm H2O (18-46 cm H2O) after tilting (P = 0.02). PaO2, PaCO2, FE/CO2, and pH did not change after tilting in the head-down position or after insufflation. HR did not change during the anesthetic period. Mean arterial pressure did not change after tilting or abdominal insufflation, but decreased by the end of the anesthetic period (approximately 1 hr). Time from intubation to extubation was 117 min (72-170 min) (n = 5) and surgery time was 31 min (17-60 min; n = 10). We conclude that captured white-tailed deer have minimal derangements to acid-base, blood gas, or physiologic parameters during laparoscopy in the head-down position with abdominal insufflation, and thus this procedure may be performed safely in ventilated white-tailed deer.