Assessment and comparison of microcirculation and macrocirculation in horses undergoing emergency exploratory celiotomy versus elective surgical procedures.

OBJECTIVE: To assess oral buccal microcirculation by hand-held videomicroscopy in horses during colic surgery, comparing microcirculation values with macrocirculatory parameters and with those of healthy elective surgical horses. STUDY DESIGN: Clinical prospective study. ANIMALS: Client-owned horses (nine in the colic group; 11 in the elective group). METHODS: In the colic group, buccal mucosal side stream dark-field microscopy (DFM) videos, cardiac output (CO), mean arterial pressure (MAP), and lactate were obtained at three timepoints under general anesthesia (30, 90, and 150 min after induction). Video analysis was used to determine total vessel density, proportion of perfused vessels, perfused vessel density, and heterogeneity index. Dark-field microscopy videos, MAP, and lactate were obtained at a single timepoint under general anesthesia (45 min after induction) in the elective group. RESULTS: There were no differences in microcirculatory parameters between colic and elective horses, nor was there a difference across timepoints in the colic group. There was a weak negative correlation between microvascular parameters and CO (rho = -0.23). CONCLUSION: The colic group did not have decreased microcirculation in comparison with the healthy elective group. Dark-field microscopy did not correlate well with macrocirculatory parameters in the colic group. IMPACT: Dark-field microscopy may not be a sensitive enough indicator to detect differences in microcirculation between colic and elective groups. The lack of difference in microcirculation may be due to sample size, probe location, or variation in disease severity.

Fragment size is associated with post-operative complications following elective arthroscopy of the tibiotarsal joint of horses.

The objective of this retrospective study was to determine the occurrence of joint-related complications after elective arthroscopy of the tibiotarsal joint (TTJ) in 329 horses, and the association with specific clinical parameters. Data were collected from medical records of horses undergoing elective tibiotarsal joint arthroscopy for fragment removal. Exact conditional univariate regression was used to determine significant risk factors for joint-related post-operative complications. Of 485 joints, 2 (0.4%) developed surgical site infection, 4 (0.8%) developed septic arthritis, 1 (0.2%) developed synovial fistula. There was a significantly increased odds of having septic arthritis as height and length of the distal intermediate ridge of the tibia (DIRT) lesion increased. The median height and length of the DIRT fragments in affected cases was 13.5 mm and 18.0 mm, respectively. For each unit (1 mm) increase in height, there was a 42% increase in the risk of septic arthritis occurrence (P = 0.0042), and a 15% increase for each unit increase in length (P = 0.035). Horses were significantly less likely to develop septic arthritis when suture smaller than USP 0 was used. Horses with larger osteochondritis dissecans lesions of the DIRT region have an increased risk of developing septic arthritis following fragment removal.

La taille des fragments est associée à des complications postopératoires après arthroscopie élective de l'articulation tibiotarsienne des chevaux. L'objectif de cette étude rétrospective était de déterminer la fréquence de complications articulaires après arthroscopie élective de l'articulation tibiotarsienne (TTJ) chez 329 chevaux, et l'association avec des paramètres cliniques spécifiques. Les données ont été recueillies à partir des dossiers médicaux de chevaux subissant une arthroscopie élective de l'articulation tibiotarsienne pour l'élimination de fragments. Une régression univariée conditionnelle exacte a été utilisée pour déterminer les facteurs de risque significatifs de complications postopératoires liées aux articulations.Sur 485 articulations, deux (0,4 %) ont développé une infection du site opératoire, quatre (0,8 %) une arthrite septique, et une (0,2 %) une fistule synoviale. Il y avait une probabilité significativement accrue d'avoir une arthrite septique à mesure que la hauteur et la longueur de la lésion de la crête intermédiaire distale du tibia (DIRT) augmentaient. La hauteur et la longueur médianes des fragments DIRT dans les cas affectés étaient respectivement de 13,5 mm et de 18,0 mm. Pour chaque unité (1 mm) d'augmentation de hauteur, il y avait une augmentation de 42 % du risque de survenue d'arthrite septique (P = 0,0042); et une augmentation de 15 % pour chaque augmentation unitaire de longueur (P = 0,035). Les chevaux étaient significativement moins susceptibles de développer une arthrite septique lorsqu'une suture plus petite que USP 0 était utilisée.Les chevaux présentant des lésions d'ostéochondrite disséquante plus importantes de la région DIRT ont un risque accru de développer une arthrite septique après le retrait des fragments.(Traduit par Dr Serge Messier).

Circulating miRNome of Trachemys scripta after elective gonadectomy under general anesthesia.

Post-surgical management is an important issue in veterinary medicine, requiring biomarkers with high sensitivity and specificity for timely and effective treatment. Emerging evidence suggests that miRNAs are promising stress- and pain-related markers. The aims were to profile the circulating miRNA signature in plasma of turtles (Trachemys scripta) and point out potential candidate biomarkers to assess the status of the animal. The plasma of female turtles underwent surgical gonadectomy were collected 24 h pre-surgery, and 2.5 h and 36 h post-surgery. The expression of miRNAs was profiled by Next Generation Sequencing and the dysregulated miRNAs were validated using RT-qPCR. The diagnostic value of miRNAs was calculated by ROC curves. The results showed that 14 miRNAs were differentially expressed over time. RT-qPCR validation highlighted that 2-miR-499-3p and miR-203-5p-out of 8 miRNAs tested were effectively modulated. The Area Under the Curve (AUC) of miR-203-5p was fair (AUC 0.7934) in discriminating pre- and 36 h post-surgery samples and poor for other time points; the AUC of miR-499-3p was excellent (AUC 0.944) in discriminating pre-surgery and 2.5 h post-surgery samples, and fair in discriminating pre-surgery and 36 h post-surgery (AUC 0.7292) and 2.5 h and 36 h post-surgery (AUC 0.7569) samples. In conclusion, we demonstrated for the first time that miRNAs profile changes in plasma of turtles underwent surgical oophorectomy and identified miR-203-5p and miR-499-3p as potential candidate biomarkers to assess animals' status. Further studies are necessary to confirm their diagnostic value and to investigate functional and mechanistic networks to improve our understanding of the biological processes.

Sevoflurane or isoflurane anaesthesia? A prospective, randomised blinded clinical trial in horses undergoing elective surgery.

BACKGROUND: Isoflurane is the only volatile anaesthetic agent licensed for equine use in the United Kingdom, but sevoflurane is also commonly used. The two agents have rarely been compared for use in clinical elective surgery. METHODS: This single centre, prospective, randomised, blinded clinical investigation recruited 101 healthy client owned horses undergoing elective surgery. Anaesthesia was standardised and horses randomly assigned to receive isoflurane (I) or sevoflurane (S) for maintenance of anaesthesia in 100% oxygen. Horses were ventilated to normocapnia and received intravenous fluid therapy and haemodynamic support with dobutamine to maintain mean arterial blood pressure above 60 mm Hg. Recovery was timed and video-recorded to allow offline evaluation by two experienced clinicians unaware of the volatile agent used. No post-anaesthetic sedation was administered. RESULTS: There was no significant difference between groups in terms of haemodynamic support required during anaesthesia nor in quality or duration of recovery. Inotropic support to maintain MAP above 60 mm Hg was required by 67 of 101 (67%) of horses. Five horses in the I group required additional ketamine or thiopentone to improve the plane of anaesthesia. CONCLUSIONS: Haemodynamic support needed during anaesthesia as well as the duration and quality of recovery were similar with isoflurane and sevoflurane.

Preoperative autologous blood donation and transfusion in dogs undergoing elective surgical oncology procedures with high risk of hemorrhage.

OBJECTIVE: To describe preoperative autologous blood donation (PABD) and transfusion in dogs undergoing elective surgical oncology procedures with a high risk of intraoperative hemorrhage. STUDY DESIGN: Prospective study. ANIMALS: Twelve dogs. METHODS: Dogs undergoing surgical oncology procedures associated with a high risk of hemorrhage were enrolled. Blood was collected a minimum of 6 days before surgery and separated into fresh frozen plasma (FFP) and packed red blood cells (pRBC). Dogs received FFP at the start of surgery and pRBC intraoperatively when hemorrhage ensued. The mean packed cell volume/total solids (PCV/TS) were calculated on the day of PABD preoperatively, immediately postoperatively, and 24 hours after transfusion. The dogs were monitored for transfusion-related adverse reactions, including hyperthermia, hypotension, tachycardia, bradycardia, pale mucous membranes, prolonged capillary refill time, or tachypnea/dyspnea. RESULTS: Dogs enrolled in the study underwent mandibulectomy, maxillectomy, chest wall resection, and liver lobectomy. Ten of the 12 dogs that underwent PABD received autologous transfusion at first signs of hemorrhage intraoperatively. Iatrogenic anemia was noted in two dogs (PCV 30% and 31%). The mean PCV/TS levels on the day of blood collection, preoperatively, immediately postoperatively (after transfusion), and 24 hours posttransfusion were 45.1%/7.1 g/dL, 42.2%/6.73 g/dL, 33.2%/5.42 g/dL, and 36.5%/5.65 g/dL, respectively. No dog developed transfusion-related complications. CONCLUSION: Preoperative autologous blood donation was well tolerated and led to uneventful autologous transfusion in 10 of 12 dogs. CLINICAL SIGNIFICANCE: Preoperative autologous blood donation and autologous transfusion are feasible for dogs undergoing elective surgical procedures with a high risk of hemorrhage.

Retrospective evaluation of association between perioperative antimicrobial protocol and complications following elective equine synovial endoscopy.

BACKGROUND: Prophylactic perioperative antimicrobial protocols in equine synovial endoscopy have been described but not compared with respect to post-operative outcomes and complications. Increasing antimicrobial resistance in equine practice and interest in promoting judicious use of antimicrobials has prompted reevaluation of drug selection and dosing strategies. OBJECTIVES: To determine the frequency of and compare post-operative complications following elective synovial endoscopy between horses receiving different perioperative antimicrobial protocols. METHODS: Records from the Colorado State University Veterinary Teaching Hospital were evaluated (2014-2018) and equine patients undergoing elective synovial endoscopy were identified. Patients undergoing endoscopy for sepsis or internal fixation were excluded. Patient signalment, clinician, joint and limb involved, perioperative antimicrobial regimen, number endoscopic portals and closure technique, and post-operative complications including incidence of joint infection were recorded. Generalized linear models were used to estimate the odds of post-operative complications. RESULTS: Elective synovial endoscopies of 516 horses in 537 procedures evaluating 761 synovial structures were performed. No horses developed post-operative septic synovitis. Administration of post-operative antimicrobials, type used and patient sex were all significantly associated with increased risk of complications, which were predominantly gastrointestinal-related. Complication rates in horses receiving a single preoperative dose of cefazolin were lower than in horses receiving potassium penicillin, gentamicin or multiple doses. Complication rates were lower in females compared to castrated or intact males. Other factors evaluated (breed, age, surgeon, anaesthesia duration or hospitalization, joint/limb operated, number endoscopic portals) were not associated with increased risk of complications post-operatively in this case population. CONCLUSIONS: Prophylactic perioperative antimicrobial protocols in equine practice deserve periodic reconsideration due to increased antimicrobial resistance. Prolonged antimicrobial usage beyond the time of surgery was unnecessary to prevent septic synovitis following synovial endoscopy in this case population and was furthermore associated with an increased risk of gastrointestinal complications.

Effect of peri-operative crystalloid fluid rate on circulating hyaluronan in healthy dogs: A pilot study.

Hypervolemia can damage the endothelial glycocalyx, a key regulator of vascular permeability, coagulation and inflammation. A starting peri-operative crystalloid fluid rate of 5mL/kg/h is recommended for healthy dogs undergoing elective procedures but higher rates continue to be commonly used. This study aimed to determine if a higher starting perioperative fluid rate was associated with a greater increase in plasma concentrations of hyaluronan, a marker correlated with glycocalyx damage, in systemically healthy dogs undergoing elective surgical procedures. Based on a sample size calculation, 38 dogs undergoing ovariohysterectomy or castration were randomly assigned to receive lactated Ringer's at a starting perioperative fluid rate of 10mL/kg/h (n=19) or 5mL/kg/h (n=19). Plasma hyaluronan concentrations were measured by ELISA in pre- and post-fluid therapy samples. There were no significant differences between groups in hyaluronan values before (baseline, P=0.52) or after perioperative fluid administration (P=0.62). Compared to respective baseline values, hyaluronan values significantly increased following 5 and 10ml/kg/h fluid administration (P=0.02 for both comparisons). This preliminary study identified an increase in hyaluronan over the course of fluid therapy with both the low and high fluid rate. One possible explanation is that both fluid rates contribute to glycocalyx disruption, but it should be emphasized that hyaluronan is not specific to the glycocalyx. Further studies are needed to determine the origin of the increased circulating hyaluronan and its clinical significance in dogs undergoing elective surgical procedures.

Serological prevalence of six vector-borne pathogens in dogs presented for elective ovariohysterectomy or castration in the South central region of Texas.

BACKGROUND: Most vector-borne pathogens cause zoonotic diseases. These zoonoses often have wild animal reservoirs that play a significant role in disease epidemiology. However, pet animals have also been implicated in transmission of zoonotic agents to humans. To exemplify, dogs are competent reservoir hosts for several zoonotic vector-borne bacteria and protozoa. Despite that vector-borne diseases can be life-threatening for both pets and humans, studies on pathogen seroprevalence are very limited. Therefore, the objective of this study was to determine the serological prevalence of six zoonotic vector-borne agents in dogs from the South Central region of Texas (US). Electronic medical records of dogs, presenting over 2014-2019 for elective ovariohysterectomy or castration at a high volume spay and neuter clinic, were reviewed for serological testing. Sera from 418 dogs were tested for the Dirofilaria immitis antigen, and antibodies to Anaplasma phagocytophilum, Anaplasma platys, Borrelia burgdorferi, Ehrlichia canis, and Ehrlichia ewingi, using a commonly available commercial test kit. Descriptive statistics were computed to characterize the respective seroprevalence rates of the dog population. The study involved 192 (46%) male and 226 (54%) female dogs. RESULTS: Overall, 85 (20%) dogs tested positive for at least one of the 6 pathogens investigated. The highest seroprevalence rate averaged over the 6-year period was 11.7% for D. immitis followed by 8.4% for E. canis and/or E. ewingii, 4.3% for A. phagocytophilum and/or A. platys, and 0.2% for B. burgdorferi. The co-exposure or co-infection was only detected in 3.8% of the dog population. CONCLUSIONS: Together, opportunistic testing of dogs presenting for elective surgical procedures may provide an effective way of assessing seroprevalence and/or risk factors for common vector-borne diseases within a geographic region of concern.

Towards scheduled pre-parturient caesarean sections in bitches.

Elective caesarean section (CS) is the safest means of delivering the litter in bitches in specific situations. Timeously performing elective pre-parturient CSs at a fixed time would be convenient and prevent emergency CSs and foetal demise. This review proposes a method of performing elective pre-parturient CSs which is safe for both the bitch and puppies. Brachycephaly, small litters and large litters, preceding litter delivered by CS and trial of labour after a preceding CS are identified as factors increasing the need for CS whereas emergency CS is identified as factor increasing foetal demise. The first day of cytological dioestrus more precisely predicts the day of onset of spontaneous parturition than the first day of the LH surge or the dates during oestrus on which progesterone (P4) first exceeds 6 nM or 16 nM. Foetal biparietal diameter at the time of onset of spontaneous parturition varies too much to accurately predict readiness for CS. During the last few days of gestation, P4 with cut-off concentrations at 15.8, 8.7 and 3.18 nM, but not plasma cortisol concentrations, hold promise as predictors of onset of parturition and when to perform pre-parturient CSs. A protocol associating medetomidine hydrochloride as premedicant with propofol as induction agent and sevoflurane as maintenance is safe for scheduled CS and yields good maternal and puppy survival rates at delivery, 2 hr and 7 days after CSs. Clinicians have to pay attention to the haematocrit of bitches at the time of cervical dilatation which is at the lower end of the normal reference ranges for non-pregnant dogs and to the decline in haematocrit during CS (as a proxy for blood loss) which is approximately 7% for both parturient (open cervix) and pre-parturient (closed cervix) CSs. Pre-parturient CSs can be scheduled and performed 57 days after onset of cytological dioestrus with puppy survival rates of 99%. Collectively, these studies provide a protocol to safely perform elective CSs in a large proportion of the obstetric population at a convenient time of the day but more research is required with larger numbers to establish whether this practice is routinely safe and safe in all breeds.

Retrospective assessment of perioperative antimicrobial use for elective arthroscopy in horses.

OBJECTIVE: To describe perioperative antimicrobial use in horses undergoing elective arthroscopy. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Horses that underwent elective arthroscopy at one institution between July 2016 and May 2018, excluding those with a suspected infectious orthopedic disease or with a comorbidity that may have impacted prophylactic antimicrobial use decisions. METHODS: Medical records were reviewed to evaluate preoperative, intraoperative, and postoperative antimicrobial drug selection, dose, and timing. Associations between body weight and underdosing were evaluated by using analysis of variance, χ2 test was used for categorical comparisons, and least squares fit was used to evaluate factors associated with duration of postoperative antimicrobials. RESULTS: Among 150 horses, 149 (99.3%) received systemic preoperative antimicrobials. Only 53 (40.2%) horses were administered doses within 60 minutes of surgical incision. First incision was performed more than two half-lives after administration of sodium penicillin in 46 of 131 (35.1%) horses but in only 1 of 106 (0.8%) horses that received trimethoprim-sulfadoxine. Body weight was associated with underdosing for penicillin (P = .0075) and trimethoprim-sulfadoxine (P = .002) but not gentamicin (P = .92). Twenty-six (17%) horses received one postoperative antimicrobial dose, while antimicrobials were continued in hospital for a mean of 22.3 ± 4.4 hours after surgery in the other 123 horses. Among the 149 discharged horses, 115 (77.2%) were prescribed antimicrobials after discharge (range, 3-10 days; median, 3 days, interquartile range, 0 days). CONCLUSION: Deviations from common recommendations were apparent and provide evidence for the requirement to develop interventions to optimize perioperative prophylaxis. CLINICAL SIGNIFICANCE: Perioperative antimicrobial use practices should be regularly assessed to provide a benchmark and identify areas for intervention.

Comparison between head-tail-rope assisted and unassisted recoveries in healthy horses undergoing general anesthesia for elective surgeries.

OBJECTIVE: To compare attempts to stand, duration, quality, and occurrence of injuries between head-tail rope assistance and unassisted recoveries in healthy horses undergoing general anesthesia for elective surgeries. STUDY DESIGN: Randomized, prospective, clinical trial. METHODS: Three hundred one healthy horses undergoing elective surgeries were randomly assigned to recover with head-tail rope assistance (group A) or unassisted (group U); 305 recoveries (group A, n = 154; group U, n = 151) were analyzed. Anesthesia was maintained with isoflurane and triple drip. For each recovery, attempts to stand, duration, quality, and recovery-associated injuries were recorded. Data were analyzed by linear regression and analysis of covariance. RESULTS: Anesthesia duration was similar between groups (mean ± SD, 70 ± 29 minutes). Compared with group U, group A had fewer attempts to stand (median [range], group A = 1 [1-7] vs group U = 3 [1-34]) and shorter duration of recovery (mean ± SD, A = 36 ± 12 minutes vs U = 41 ± 15 minutes). Recovery quality in group A (28 points [15-70]) was better than that in group U (38 points [11-87]). More horses had recovery-associated injuries in group U (9 horses) compared with group A (2 horses). One horse per group was euthanized. CONCLUSION: Head-tail rope assistance reduced standing attempts, shortened recovery duration, improved recovery quality, and reduced recovery-associated minor injuries after general anesthesia for elective surgery in healthy horses. Fatalities could not be prevented. CLINICAL SIGNIFICANCE: Head-tail rope assistance may improve recovery in healthy horses after short-duration elective surgeries with isoflurane and triple drip.

Prophylactic antibiotic usage by Belgian veterinarians during elective caesarean section in Belgian blue cattle.

The use of prophylactic antibiotics in veterinary surgery reduces the occurrence of postoperative complications. In order to limit the development of antimicrobial resistance in bacteria and to maximize therapy efficacy, antibiotics should be used prudently and efficiently. A survey was sent to Wallonian rural veterinarians in order to assess the use of antibiotics before, during and after bovine elective caesarean section, the most common surgical procedure in Belgian rural practice. Results were analysed in the light of the current guidelines formulated by the Belgian Centre of Expertise on Antimicrobial Consumption and Resistance in Animals. Among 380 contacted veterinarians, 113 answered the survey. All veterinarians use antibiotics during caesarean section. Veterinarians predominantly use penicillin as the first drug of choice, whereas a minority use drugs considered as second or third choice, such as amoxicillin, oxytetracyclin or lincomycin-spectinomycin. Also, 31/113 veterinarians simultaneously use molecules from different antibiotic classes. The majority (100/113) of veterinarians inject antibiotics during or after surgery, while a minority (13/113) administer antibiotics preoperatively. Most veterinarians (67/113) limit the duration of their antibiotic treatment to 1 day. Considering the administration route, most veterinarians (88/113) systematically use the intraperitoneal injection route, which is not registered. Intramuscular injection and injection between muscle layers during surgery are carried out by 82/113 and 43/113 respondents, respectively. Twenty-two respondents apply intra-uterine antibiotics. Most veterinarians (87/113) combine several administration routes. The dosage of antibiotics varies enormously and excessive injection volumes are common, especially when multiple injection routes are combined. Our results show a striking lack of consistency in the antibiotic therapy during elective CS by rural veterinarians. Whereas the drug of choice and the treatment duration were largely in line with the current guidelines, this is certainly not the case for the dosage and the administration route. The intraperitoneal injection of antibiotics cannot be justified. Incorrect dosage of antibiotics should be avoided at all cost. The use of second and third line molecules and the simultaneous use of different antibiotic classes should be discouraged. A major challenge lies in the education of veterinary students and the sensitization of practitioners to avoid or unlearn unnecessary habits concerning antibiotic use. Finally, more clinical trials are needed in order to refine the current guidelines for antibiotic use and to determine the optimal drug of choice, treatment moment and application route in elective caesarean section in cattle.

Differences in the equine faecal microbiota between horses presenting to a tertiary referral hospital for colic compared with an elective surgical procedure.

BACKGROUND: The faecal microbiota is emerging as potentially important in intestinal disease. More research is needed to characterise the faecal microbiota from horses with colic. OBJECTIVES: To compare the relative abundance of bacterial populations comprising the faecal microbiota in horses presenting for colic compared with an elective surgical procedure. STUDY DESIGN: Prospective observational clinical study. METHODS: Admission faecal samples were collected from horses presenting for colic and elective surgical procedures. Faecal samples were extracted for genomic DNA, PCR- amplified, sequenced and analysed using QIIME. Species richness and Shannon diversity were estimated for each faecal sample. The extent of the relationship between bacterial communities (beta diversity) was quantified using pairwise UniFrac distances, visualised using principal coordinate analysis (PCoA) and statistically analysed using PERMANOVA. The relative abundance of bacterial populations between the two treatment groups were compared using ANCOM. RESULTS: Faecal bacterial communities in horses presenting for colic had fewer species (P<0.001) and lower diversity (P<0.001) compared with horses presenting for elective surgical procedures. Based on the PERMANOVA analysis, there was a significant difference in the bacterial community composition between horses admitted for colic vs. elective procedures (P = 0.001). Based on ANCOM test, at the genus level, 14 bacterial lineages differed between the two groups. The relative abundance of known commensal bacteria including Prevotella, Clostridia, Lachnospiraceae were reduced whereas Christenellaceae, Streptococcus and Sphaerochaeta were increased in horses with colic when compared with elective cases. MAIN LIMITATIONS: Relative low numbers and a diverse population of horses. CONCLUSIONS: Changes in bacterial populations in the faecal microbiota of horses presenting for colic observed in this study concurs with previous studies in veterinary and human patients with gastrointestinal disease. Future studies focusing on different causes of colic, chronic or recurrent disease, and the association with histological changes within the intestine are needed. The Summary is available in Portuguese - see Supporting Information.

Peripheral perfusion index does not accurately reflect hypoperfusion in healthy dogs undergoing elective ovariohysterectomy.

This study evaluated the variability of the peripheral perfusion index (PI) in 22 anaesthetised female dogs undergoing elective ovariohysterectomy and examined the relationship between peripheral PI and heart rate, blood pressure, blood pH, end tidal CO2 (EtCO2), O2 saturation (SpO2), core-peripheral temperature gradient (ΔTc-p), partial pressure of CO2 (PCO2), and concentrations of glucose, cortisol, lactate and bicarbonate (HCO3-). Blood pH, lactate and glucose concentrations were determined 15, 30, 45min into the ovariohysterectomy procedure and after extubation. Cortisol concentrations were assessed before anaesthesia and after extubation. Other variables were recorded at every 5min throughout the ovariohysterectomy procedure. Hyperglycaemia was observed in 59% of bitches during surgery, but serum cortisol concentrations remained unchanged. Most measures of perfusion (ΔTc-p, pH, PCO2, EtCO2, SpO2) and heart rate remained unchanged throughout anaesthesia and did not correlate with peripheral PI. Mean arterial pressure increased during the ovariohysterectomy procedure, while peripheral PI decreased, resulting in negative correlations between these variables at 30 and 45min. Lactate concentrations decreased from baseline to the time of measurement post-extubation. Peripheral PI gradually decreased during the ovariohysterectomy procedure, probably reflecting vasoconstriction induced by nociceptive stimuli. Using lactate concentrations as the reference standard for peripheral perfusion, low peripheral PI in healthy bitches undergoing ovariohysterectomy might not represent peripheral hypoperfusion.

Effect of routine pre-anesthetic laboratory screening on pre-operative anesthesia-related decision-making in healthy dogs.

The usefulness of pre-anesthetic laboratory screening of healthy veterinary patients is controversial and clear evidence-based guidelines do not exist. The purpose of our study was to determine the influence of preanesthetic laboratory screening on peri-anesthetic plans in canine patients undergoing elective surgery. One hundred medical records were randomly selected between the years 2008 and 2013 and patient information was presented to 5 Diplomates of the American College of Veterinary Anesthesia and Analgesia (ACVAA) for review. They were given pre-anesthetic laboratory screening test results for each patient and asked whether the results would change the way they managed the case from an anesthesia perspective. Peri-operative anesthetic management was altered in 79% of patients based on pre-anesthetic screening results; however, the overall agreement among anesthesiologists was weak with 64% of changes made by only a single anesthesiologist. Pre-anesthetic laboratory screening test results may influence pre-operative anesthesia case management but major discrepancies can occur among ACVAA diplomates.

Effet du dépistage de laboratoire pré-anesthésique de routine sur la prise de décisions préopératoires liées à l'anesthésie chez des chiens en santé. L'utilité du dépistage de laboratoire pré-anesthésique des patients vétérinaires en santé est controversée et des lignes directrices claires basées sur des données probantes n'existent pas. Le but de notre étude consistait à déterminer l'influence du dépistage de laboratoire pré-anesthésique pour la péri-anesthésie chez les patients canins subissant une chirurgie non urgente. Cent dossiers médicaux choisis au hasard entre les années 2008 et 2013 et des données sur les patients ont été présentés à cinq diplomates de l'American College of Veterinary Anesthesia and Analgesia (ACVAA) aux fins d'examen. On leur a donné les résultats des tests de dépistage de laboratoire pré-anesthésiques pour chaque patient et on leur a demandé d'évaluer si les résultats auraient modifié la façon dont ils auraient géré le cas du point de vue de l'anesthésie. La gestion anesthésique péri-opératoire a été modifiée chez 79 % des patients en se basant sur les résultats du dépistage préanesthésique. Cependant, le consensus général parmi les anesthésiologistes était faible avec 64 % des changements apportés par seulement un seul anesthésiologiste. Les résultats des tests de dépistage de laboratoire pré-anesthésiques peuvent influencer la gestion des cas d'anesthésie préopératoire mais des écarts majeurs peuvent se produire parmi les diplomates de l'ACVAA.(Traduit par Isabelle Vallières).

Effects of hetastarch 130/0.4 on plasma osmolality, colloid osmotic pressure and total protein in horses anaesthetised for elective surgical procedures.

Effects of lactated Ringer's solution (LRS) and hetastarch 130/0.4 (HES) on colloid osmotic pressure (COP), plasma osmolality (OSM) and total protein (TP) were investigated in 18 inhalational-anaesthetised healthy horses. Horses received 4-6 ml/kg LRS (LRS; n=9) or HES (HES; n=9) from anaesthesia induction through 60 min, after which all were administered LRS. COP, TP and OSM were measured before premedication (baseline), postinduction and 30 (n=18), 60 (n=18), 90 (n=18) and 120 (n=12) minutes. Baseline COP, OSM and TP were not different between groups. TP decreased in both groups at all time points after induction. OSM increased from baseline in HES at 30, 60, 90 and 120 minutes. COP decreased at 30-120 minutes in LRS, and at 90 and 120 minutes in HES. Mean COP was higher in HES than LRS at 30 (18.8±0.5 vs 16.3±0.4 mmHg (P=0.001)), 60 (19.1±0.5 vs 15.9±0.4 mmHg (P<0.0001)) and 90 (17.4±0.5 vs 15.4±0.5 mmHg (P=0.005)) minutes. Sixty minutes of HES infusion increases OSM and transiently maintains COP compared with an equal volume of LRS in anaesthetised horses.

Outcome of elective cholecystectomy for the treatment of gallbladder disease in dogs.

OBJECTIVE To determine mortality rates for dogs undergoing cholecystectomy and variables associated with failure to survive to hospital discharge. DESIGN Retrospective cohort study. ANIMALS 70 dogs that underwent cholecystectomy for biliary tract disease at a companion animal referral hospital from 2009 through 2015. PROCEDURES Medical records of dogs were reviewed and data collected; dogs with biliary diversion surgery were excluded. Included dogs were grouped by whether cholecystectomy had been elective (ie, dogs with no or mild clinical signs, with no indication of biliary obstruction, or that initially underwent surgery for a different procedure) or nonelective (ie, dogs with icterus and questionable patency of the biliary system). Mortality rates (proportions of dogs that failed to survive to hospital discharge) were compared between various groups. RESULTS 45 (64%) dogs were included in the elective group and 25 (36%) in the nonelective group. Group mortality rates were 2% (1/45) and 20% (5/25), respectively, and differed significantly. Overall mortality rate was 9% (6/70). Serum albumin concentration was significantly lower and serum alanine aminotransferase activity and total bilirubin concentration were significantly higher in nonsurviving versus surviving dogs. Dogs with vomiting, signs of lethargy or anorexia, icterus, or azotemia were less likely to survive than dogs without these signs. CONCLUSIONS AND CLINICAL RELEVANCE Dogs that underwent elective cholecystectomy had a considerably lower mortality rate than previously reported. Elective cholecystectomy may be an appropriate recommendation for dogs with early signs of biliary disease to avoid the greater mortality rate associated with more advanced disease and nonelective cholecystectomy.

Changes in D-dimer concentration after soft tissue and orthopedic surgery in dogs.

OBJECTIVE: D-dimer is a specific marker of active coagulation and fibrinolysis. The objective of this study is to determine the influence of surgery on D-dimer concentration as well as to examine the relation between the magnitude of change and invasiveness of the surgical procedures. STUDY DESIGN: Prospective clinical study. ANIMALS: Forty-five client-owned dogs undergoing elective neutering (n = 15), elective orthopedic (n = 15), or posttraumatic orthopedic (n = 15) surgical procedures. METHODS: Dogs undergoing elective neutering, elective orthopedic, and posttraumatic orthopedic surgical procedures were enrolled. D-dimer concentration, measured immediately prior to, immediately after, and 24 hours after surgery (T0, T1, and T24, respectively), was compared within and among study groups. RESULTS: D-dimer concentration was >250 ng/mL in 8 (18%) dogs at T0, in 9 (20%) at T1, and in 5 (11%) at T24. At T1 and T24, only 2 dogs had a D-dimer concentration >500 ng/mL, and it was <750 ng/mL in all dogs. There was no difference in the proportion of increased D-dimer concentration (>250 ng/mL) among the time points (P = 0.29). Median D-dimer concentration did not vary between time points within the groups, except in the neutering group (P = 0.029), in which T1 concentration tended to increase compared with T0 values (161 ng/dL, range 71-727 vs 122 ng/mL, range, 43-353, respectively; P = .065). CONCLUSION: The surgical procedures tested in this study are unlikely to cause a direct increase in D-dimer concentration. CLINICAL SIGNIFICANCE: Any increase in D-dimer concentration after elective neutering, elective orthopedic, and posttraumatic orthopedic surgical procedures should be regarded as clinically important and trigger investigations to detect a hemostatic derangement.

Incidence and risk factors of surgical site infection and septic arthritis after elective arthroscopy in horses.

OBJECTIVE: To determine the incidence of infection and associated risk factors, after elective arthroscopy. STUDY DESIGN: Retrospective case study. ANIMALS: Horses (n=1079) undergoing elective arthroscopy. METHODS: Medical records of all horses that underwent elective arthroscopy between 2006 and 2013 were reviewed. Age, gender, breed, surgeon, number of joints operated, total anesthetic time, perioperative antimicrobial administration, and the presence and size of osteochondral fragments/subchondral lesions were recorded. For each operated joint, the development of postoperative infection (surgical site infection [SSI] and/or septic arthritis) and long-term outcome (>6 months) were recorded. Multivariate logistic regression was used to test for association between the independent variables and the dependent outcomes. RESULTS: A total of 1741 joints in 1079 horses underwent arthroscopy. SSI without septic arthritis occurred in 1 fetlock joint (0.14%), 1 tibiotarsal joint (0.19%), and 6 femoropatellar joints (1.67%). Thirteen joints (0.75%) were diagnosed with septic arthritis, including 1 fetlock joint (0.14%), 4 tibiotarsal joints (0.74%), and 8 femoropatellar joints (2.23%). The probability of postoperative SSI was higher when large lesions (>40 mm long) were treated, compared to medium (20-40 mm, P = .005) and small (<20 mm, P < .001) lesions. SSI was a significant risk factor for the development of septic arthritis (P < .001). Although age did not affect the incidence of SSI, increasing age was associated with a lower rate of septic arthritis rate (P = .028). CONCLUSION: Septic arthritis after elective arthroscopy was more likely in the presence of SSI and younger age. Horses with large lesions were at risk for SSI, which translated into a higher incidence of postoperative septic arthritis after femoropatellar arthroscopy.