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Objective To develop an ultrasound (US)-guided transversus abdominis plane (TAP) block in pigs. Study design Prospective, descriptive, experimental study. Animals A total of 26 hemi-abdomens belonging to 13 Seghers Hybrid cadavers. Methods The study consisted of two parts. In part 1, a preliminary anatomical understanding of the abdominal wall innervation in pigs was established (two hemi-abdomens of one pig). Part 2 was divided into three phases, and a US-guided TAP technique using methylene blue dye (0.3 mL kg–1 for each hemi-abdomen) was developed. In chronological order, a pilot study (phase I) was conducted to establish good injection points (four hemi-abdomens). In phase II a two-point injection technique (10 hemi-abdomens) was performed. A cranial injection was made at two-thirds of the distance between the xyphoid process and the iliac crest, immediately ventral to the rib arch. A caudal injection was performed ventral to the last rib. In phase III a three-point injection technique was performed (10 hemi-abdomens) with an extra injection point halfway between the cranial and caudal injection point. Staining of the different nerves was recorded during dissection. Results In part 1 the nerves innervating the pig’s abdominal wall, thoracic vertebrae 12–16 (T12–16) and lumbar vertebrae 1–3 (L1–3), were identified. In part 2, data from the pilot study, adequate nerve staining with the two- or three-point injection technique, were obtained in T12 (29 versus 45% respectively), T13 (29 versus 100%), T14 (73 versus 45%), T15 (75 versus 78%), T16 (58 versus 78%), L1 (100 versus 75%), L2 (88 versus 84%) and L3 (23 versus 0%). Conclusions and clinical relevance US-guided TAP block can be used in swine but only a moderate success rate for adequate nerve staining was achieved in this study. Further studies are necessary to determine a correct injection volume and assess clinical intra- and postoperative efficacy.

To study the antinociceptive properties of epidural magnesium sulphate (MgSOEpidural MgSOEpidural administration of MgSO

A bolus of 50 mg kg

To evaluate the effects of detomidine or romifidine on cardiovascular function, isoflurane requirements and recovery quality in horses undergoing isoflurane anaesthesia.Prospective, randomized, blinded, clinical study.A total of 63 healthy horses undergoing elective surgery during general anaesthesia.Horses were randomly allocated to three groups of 21 animals each. In group R, horses were given romifidine intravenously (IV) for premedication (80 μg kgNo significant differences were observed between groups for Fe'Iso, dobutamine or ketamine requirements and recovery times. Cardiovascular and blood gas measurements remained within physiological ranges for all groups. Group D5 horses had significantly worse scores for balance and coordination (p = 0.002), overall impression (p = 0.021) and final score (p = 0.008) than group R horses and significantly worse mean scores for VAS than the other groups (p = 0.002).Detomidine or romifidine constant rate infusion provided similar conditions for maintenance of anaesthesia. Higher doses of detomidine at the end of anaesthesia might decrease the recovery quality.

Alfaxalone is a synthetic neurosteroid anesthetic agent widely used in veterinary medicine, with a wide margin of safety and good quality of anesthesia. Also, alfaxalone has rapid biotransformation and a low tendency to accumulate in the tissues after repeated doses, which favors its intravenous use as a constant rate infusion. The aim of the study was to assess the isoflurane-sparing property and the clinical effects on the cardiorespiratory system of alfaxalone used as constant rate infusion in goats. Three healthy female goats were included in the study. Each goat was anesthetized twice (interval fifteen days) and received the following treatments in a random order during maintenance of anesthesia: 1. alfaxalone administered as a constant rate infusion at 0.05 mg/kg/min (treatment A); 2. NaCl 0.9% solution at an identical infusion rate (treatment B). Isoflurane vaporizer settings were adjusted according to a flow-chart. The SpO2 was significantly lower during treatment B than during treatment A. Although no significant differences were demonstrated for the other variables (heart rate, etc.), a clinical effect was noticed, including a modest decrease in the expired isoflurane concentration with treatment A. In conclusion, the co-administration of alfaxalone in isoflurane-anesthetized goats seems to result in only minimal side effects on cardiorespiratory parameters and may reduce the isoflurane requirements, but further studies are needed to confirm these results.

Objective To describe the cardiorespiratory effects of a change in table position in anaesthetized horses. Study design Prospective, crossover, randomized, experimental study. Animals Six adult horses (mean body weight 621 ± 59 kg, aged 13 ± 4 years). Methods The horses were anaesthetized twice in dorsal recumbency. They were either placed in the Trendelenburg position (head down; HD) followed by reverse Trendelenburg position (head up; HU) or in reverse order. Every position was maintained for 90 minutes. The order of positions was randomly assigned at initial anaesthesia. Extensive cardiorespiratory monitoring was performed. Statistical analysis consisted of a mixed model with horses as random effect and time, position, section of anaesthesia and interaction between those as fixed effects (p Results When HU was applied during the first section of anaesthesia, PaO2, (p = 0.012), oxygen saturation (SaO2, p Q ˙ s/ Q ˙ t, p Q ˙ s/ Q ˙ t lower compared to the inverse order. Independent of the order, in the HD position Q ˙ s/ Q ˙ t (p = 0.019) increased while PaO2 (p v ¯ O2; p = 0.019), venous saturation (p = 0.004) and venous oxygen content (p = 0.010) decreased over time. No significant differences were found for cardiac output, oxygen delivery, oxygen consumption and dobutamine requirement between the two positions. Conclusions and clinical relevance Gas exchange is better preserved in HU compared to HD, especially if applied from the start of the anaesthesia.

Objective To evaluate the cardiorespiratory effects of a 7° reverse Trendelenburg position (RTP) in anaesthetized horses. Study design Randomized, non-blinded clinical trial. Animals A total of 125 horses undergoing elective surgery in dorsal recumbency. Methods Horses were allocated to one of three weight classes and assigned to be positioned either on a horizontal table or on a table in 7° RTP, according to a randomized block design. In all horses, anaesthesia was maintained with isoflurane in oxygen and a constant rate infusion of romifidine. All horses were mechanically ventilated throughout anaesthesia, and routine cardiovascular monitoring and arterial blood gas analysis were performed at 15-minute intervals and relevant variables calculated. Data from the first 60 minutes of anaesthesia were compared between both positions using a mixed model analysis of variance. Results A significant interaction was found between position and weight class for the alveolar to arterial oxygen tension gradient and F-shunt: these variables were lower in RTP than in horizontal position in the two lowest weight classes and vice versa in the highest weight class. Arterial oxygen tension and oxygenation indices were significantly worse in the horses in the higher weight classes. Conclusions and clinical relevance A 7° RTP did not result in clinically relevant changes in gas exchange or cardiovascular function. Horses with a higher body weight are at increased risk for hypoxaemia during anaesthesia in dorsal recumbency.

The objective of this review was to perform a literature compilation of all the equine publications that used dexmedetomidine as the first article on this topic was published, in 2005. We also aimed to answer the question whether the use of dexmedetomidine can currently be justified. For that, we compiled information from databases, such as PubMed, Google Scholar and Web of Science and the proceedings of the last veterinary anaesthesiology meetings. Dexmedetomidine is an attractive drug to be used in horses, mainly due to its pharmacokinetic profile and pharmacodynamics that favour its use as intravenous constant rate infusion (CRI). Nowadays, its clinical use is popular for sedation in prolonged standing procedures and during partial intravenous anaesthesia (PIVA) and total intravenous anaesthesia (TIVA). However, legal requirements for its use should be taken into account.

Objective To investigate the anatomy of the ear innervation in horses and develop a new approach for the block of the internal and external pinna and acoustic meatus. Study design Prospective, descriptive, cadaveric study. Animals A total of 25 heads and necks from horse cadavers. Methods Phase I: anatomical dissection and dye deposition on 19 heads. With the head positioned in lateral recumbency, 10 mL methylene blue (1:1 sterile water) for the internal auricular and 2 mL for the great auricular nerve block were injected in 21 ears (seven left, 10 right and two bilaterally). The anatomy of all the ears (bilaterally) and the accuracy of dye deposition (successful nerve staining defined as > 2 cm) was assessed following dissection. Occurrence of intraparotid, intravascular, or intraneural injection was recorded. Phase II: the same technique and volumes were applied, bilaterally, using a lidocaine 2%:iohexol solution mixture (3:1) in six different cadavers. Computed tomography was performed and the needle position and spread of the mixture evaluated and recorded. Results Phase I: Inter- and intraindividual differences were found in the anatomy of the great auricular nerve, but not in the internal and lateral auricular nerve branches and the caudal auricular nerve. No auriculotemporal nerve was found. Nerve staining was successful in 95% of the cases for the great auricular nerve, 85% of the cases for the internal auricular nerve, and 100% of the cases for the lateral auricular branch and caudal auricular nerve. Failure was observed in horses with abundant periauricular fat. No intravascular, intraparotid or intraneural injections occurred. Phase II: A 100% success rate was recorded from computed tomography images. Conclusions and clinical relevance The described approach seems suitable for blockade of the sensory innervation of the equine ear.

Piglets are considered to be suitable animal models for predicting the pharmacokinetics and pharmacodynamics (PK/PD) of test drugs for potential use in the paediatric population. Such PK/PD studies require multiple blood and urine samplings. The goal of the present study was to determine a suitable blood collection strategy applicable in the youngest age categories of six days, four weeks and eight weeks of age, as well as a urine collection technique for male piglets in the same age categories. Blood was collected either by a surgically-placed jugular vein catheter (six days old [ n = 4] and four weeks old [ n = 2] piglets) or by direct venepuncture of the jugular vein (four weeks old [ n = 2] and eight weeks old [ n = 4] piglets). A non-invasive method for total volume urine collection in male piglets was also developed using a urine pouch. No specific complications were encountered during anaesthesia or surgery for jugular catheter placement. After a 24 h recovery period, urine and blood were easily collected without technical complications. One piglet was humanely killed at week 2 because of septicaemia. Histological analysis of both veins in all four piglets revealed negligible damage to the blood vessel wall. In conclusion, the presented techniques for blood (jugular catheter and direct venepuncture) and urine collection (pouches) are suitable for PK/PD studies in piglets.

This study evaluated the Etest for direct antimicrobial susceptibility testing (AST) of bacteria from equine synovial specimens, incubated in BACTEC enrichment bottles. Ninety-four culture-positive broths were inoculated onto agar to directly determine the minimum inhibitory concentrations (MICs) of 13 antimicrobials, using the Etest (direct Etest). Results were compared with those obtained with the agar dilution reference method, the standard Etest, and the disc diffusion method, after subculture and standardisation of the inoculum. For categorical comparison of AST results, MICs were translated into susceptibility categories, using clinical breakpoints. The direct Etest predicted categorical susceptibility/resistance of bacteria from equine synovial fluid with acceptable accuracy (overall categorical agreement, 91%) and was more reliable than the disc diffusion test. The direct Etest was less accurate than the standard Etest for generating MICs ± 1 log dilution relative to the reference method (overall essential agreement, 69% vs. 89%). As the Etest generated a high percentage of inaccuracies with trimethoprim and sulfadiazine, these were less suitable antimicrobial agents for inclusion. In conclusion, the direct Etest reliably predicted the susceptibility of isolates from equine synovial fluid for the tested antimicrobials, except for trimethoprim and sulfadiazine. Since it did not require subculture and preparation of a standardised inoculum, direct Etest results were available at least 24 h earlier than with other methods, which could facilitate the diagnosis of synovial infections. However, when accuracy is prioritised over speed for MIC determination, the standard Etest is preferred over the direct Etest.

Made available in DSpace on 2019-10-06T15:37:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-05-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Objective: To determine the required rate of a detomidine infusion (loading dose 5 μg kg −1 ; initial rate 12.5 μg kg −1 hour −1 ) added to a constant infusion of methadone (0.2 mg kg −1 ; 0.05 mg kg −1 hour −1 ) for sedation in standing horses and ponies undergoing elective surgeries with appropriate local anaesthetic techniques. Study design: Prospective, clinical study. Animals: Adult, healthy, client-owned, non-food-producing horses or ponies sedated for elective standing surgeries longer than 45 minutes. Methods: At baseline (in the stables before administration of sedative agents), at 10 minutes after sedation and every 5 minutes thereafter, ataxia, sedation and surgical condition were evaluated; each scored 0–3. These scores were used to adjust the detomidine administration rate using the Ghent Sedation Algorithm. A 10 cm visual analogue scale (VAS) was used by the main surgeon at the end of the procedure to evaluate the surgical conditions. Heart rate, systolic arterial pressure and respiratory frequency were also recorded at each time point. For statistical analysis, ANOVA for normal, Kruskal–Wallis H-test for non-normal variables, and Mann–Whitney U test for VAS were used. Results: From the 42 horses/ponies included in this study, 28 underwent dental procedures and 14 other types of procedures. Overall, dental procedures required higher mean detomidine rates compared with other types of surgeries (16.9 ± 4.5 versus 9.0 ± 1.9 μg kg −1 hour −1 ) (p < 0.001). Dental procedures were assigned similar VAS scores, median (range), of 7.8 (5.8–10) with other procedures, 8.7 (2.8–10). Cardiovascular changes were not clinically significant. No signs or behavioural changes of abdominal pain were observed postoperatively. Conclusions and clinical relevance: Satisfactory surgical conditions were achieved using a combination of detomidine and methadone infusions with locoregional anaesthesia, with no adverse effects. Dental procedures required higher detomidine dose rates compared with other surgeries. The Royal (Dick) School of Veterinary Studies and the Roslin Institute University of Edinburgh School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) Faculty of Veterinary Medicine Ghent University School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) FAPESP: 2014/00474-5 FAPESP: 2017/01425-6

OBJECTIVE: To summarize the different methods used to assess sedation and/or adjust the dose or administration rate of alpha-2 agonists in horses and to propose an algorithm to adjust the administration rate of a constant rate infusion of an alpha-2 agonist in horses.DATABASES USED: PubMed and Web of Science; search terms: horse, sedation and score.CONCLUSIONS: Most authors distinguish between sedation depth, sedation quality and degree of ataxia. These three features are evaluated using scoring systems similar to those classically used to assess pain, i.e. simple descriptive scales, numerical rating scales (NRS), visual analogue scales and/or multifactorial sedation scales. In addition, head height above the ground is often used as a measure of the depth of sedation. Very few authors have described how to adjust the administration rate or dose of alpha-2 agonists. Based on the available literature, the Ghent Sedation Algorithm was developed, which assigns scores (NRS) for degree of ataxia, sedation depth and surgical conditions, and uses these to prescribe changes in the administration rate of constant rate infusions of alpha-2 agonists. Studies are needed to validate this algorithm.

Contagious respiratory infections are an important cause of respiratory disease in horses, resulting in impaired pulmonary function, poor performance and sometimes severe illness. Although bacterial infections are often suspected to be involved, viruses are frequently overlooked and are an underestimated cause of respiratory disease outbreaks in horses. In this study, nasal swabs of 103 horses with acute symptoms of respiratory disease were analyzed for the presence of 13 different respiratory pathogens. Gamma herpesviruses were the most commonly detected, with 60% of the samples being positive, followed by streptococcus equi subsp. zooepidemicus infection (30%). Rhinovirus B, streptococcus equi subsp. equi, adenovirus 1 and EHV-4 were more rarely detected. Further research is necessary to correctly interpret the importance of gamma herpesviruses in horses, for example by screening a healthy control population. National surveillance of respiratory viruses in horses by PCR analysis on nasal swabs might be a useful, earlywarning system for viral epidemics.

To examine the influence of detomidine or romifidine on recovery quality from isoflurane anesthesia, 78 anesthetic records were reviewed, from horses that had received romifidine (group R) during premedication [80–120 μg kg−1 IV], anesthetic maintenance (40 μg kg−1 hour−1 IV), and recovery (20 μg kg−1 IV) or detomidine (group D), at doses of 10–20 μg kg−1 IV, 5 μg kg−1 hour−1 IV, and 2.5 μg kg−1 IV, respectively. Duration of the different recovery phases, the number of attempts to sternal and standing, scores for transition to standing (TrSta), balance and coordination once standing (BC), and final recovery score (FS) were compared between groups using a Mann–Whitney U-test, independent t-test, or chi-squared test, as appropriate (alpha 0.05). Parametric data are represented as the mean ± standard deviation, and nonparametric data as the median (interquartile range). Compared with group D (25 horses), horses in group R (53 horses) needed significantly fewer attempts to achieve sternal recumbency [R 1 (1–1) vs. D 1 (1–2)], remained significantly longer in sternal recumbency [R 10 (3–14,5) vs. D 5 (1–9,5) minutes], needed significantly less attempts to stand [R 1 (1–1) vs. D 2 (1–4)], and a significantly shorter time to stand after making their first attempt [R 0 (0–0) vs. D 3 (0–6) minutes], with significantly better scores for TrSta, BC, and FS in group R. The results suggest that, at the doses used, romifidine provides a better recovery quality.

OBJECTIVE: To perform a literature review of the thermal and mechanical antinociceptive devices used in pharmacological studies in standing horses published after 2011 (2012-2019). To complete a full literature review about electrical stimulation used for evaluation in similar studies.DATABASES USED: PubMed, Google Scholar and Web of Science.CONCLUSIONS: A high level of standardization has been reached in antinociceptive studies in standing horses using thermal and mechanical stimuli in most recent years. Commercially available testing devices to deliver thermal, mechanical and electrical stimuli, with observation of aversive responses to these stimuli, are reliable, sensitive and specific. For electrical stimulus testing, there is evidence that the resistance between the electrodes should be measured and should not exceed 3 kΩ to guarantee consistent and reproducible stimuli. The specific analysis of electromyographic activity after an electrical stimulus provides more detailed information about the neurons stimulated.

Een acht jaar oude volbloedmerrie werd aangeboden op de Faculteit Diergeneeskunde (UGent) met acute kolieksymptomen. Een hernia diafragmatica werd vermoed aan de hand van het klinisch en echografisch onderzoek. Deze diagnose werd nadien bevestigd tijdens een spoedlaparatomie uitgevoerd diezelfde dag. Patienten met een hernia diafragmatica vormen een uitdaging voor zowel de chirurg als de anesthesist omwille van de verstoorde functie van het middenrif en de verplaatsing van de abdominale organen in de thorax. Het bekomen van optimale ventilatie en oxygenatie zonder schade aan de longen toe te brengen, is niet vanzelfsprekend. In de voorliggende casus werd een geassisteerdgecontroleerde ventilatie met een intermitterend positieve druk met een laag tidaal volume, lage druk en een iets hogere ademhalingsfrequentie toegepast. Naast problemen tijdens de ventilatie was de patient cardiovasculair gecompromitteerd. Gedurende de operatie werd, met de eigenaars toestemming, besloten het paard te euthanaseren gezien de ernst en locatie van de hernia.

A partial maxillectomy was performed in a four-year-old, 12-kg lactating female red-necked wallaby or Bennett’s wallaby ( Macropus rufogriseus ) with a diagnosis of oral necrobacillosis or ‘lumpy jaw disease’. After intramuscular administration of dexmedetomidine and ketamine, anaesthesia was maintained with isoflurane in a mixture of oxygen and medical air. A maxillary nerve block was performed through the infraorbital canal with bupivacaine 0.5 per cent (0.2 ml/kg) to provide perioperative analgesia. Inhalant anaesthesia requirements gradually decreased during maintenance of anaesthesia. Oral tramadol was administered for postoperative pain management. During the following days, no behavioural or other signs of pain or discomfort were recorded. Physiological parameters stayed within reference values.

Objectives To investigate the influence of two inspired oxygen fractions (F I O2) on the arterial oxygenation in horses anaesthetized with isoflurane. Study Design Retrospective, case-control clinical study. Animals Two hundred equine patients undergoing non-abdominal surgery (ASA class 1–2), using a standardized anaesthetic protocol and selected from anaesthetic records of a period of three years, based on pre-defined inclusion criteria. Methods In group O (n = 100), medical oxygen acted as carrier gas, while in group M (n = 100), a medical mixture of oxygen and air (F I O2 0.60) was used. Demographic data, F I O2, arterial oxygen tension (PaO2) and routinely monitored physiologic data were recorded. The alveolar-arterial oxygen tension difference [P(A-a)O2] and PaO2/F I O2 ratio were calculated. The area under the curve, standardized to the anaesthetic duration, was calculated and statistically compared between groups using t-tests or Mann–Whitney tests as appropriate. Categorical data were compared using Chi-square tests. Results No significant differences in age, body weight, sex, breed, surgical procedure, position, anaesthetic duration or arterial carbon dioxide tension were found. Mean F I O2 was 0.78 in group O and 0.60 in group M. Compared to group O, significantly lower values for PaO2 and for P(A-a)O2 were found in group M. In contrast, the PaO2/F I O2 ratio and the percentage of horses with a PaO2 Conclusions Although a reduction of the inspired oxygen fraction resulted in a lower PaO2, the P(A-a)O2 was also lower and the number of horses with PaO2 values Clinical relevance In healthy isoflurane anaesthetized horses, the use of a mixture of oxygen and air as carrier gas seems acceptable, but further, prospective studies are needed to confirm whether it results in a lower degree of ventilation/perfusion mismatching.

The aim of present study was to develop a rapid and reliable analytical method for quantification of ketamine and its major metabolite, norketamine, in bovine plasma. A cost-effective and high-throughput extraction procedure was combined with a sensitive and specific liquid chromatography–heated electrospray ionization-tandem mass spectrometry method. Sample preparation consisted of a protein precipitation step using methanol followed by a clean-up using a HybridSPE®-phospholipid column and further dilution by a factor 1/10 with water before injection onto the LC–MS/MS instrument. A gradient elution program was performed with 1 % formic acid in water and 0.1 % acetic acid in methanol as mobile phases. Ionization was performed by a heated electrospray ionization (h-ESI) probe operating in the positive ionization mode. Following transitions were monitored in the selected reaction monitoring mode: 238.0 > 124.9/220.0 for ketamine and 224.0 > 207.0/124.9 for norketamine. The method was validated in-house. Matrix-matched calibration graphs were prepared for ketamine and norketamine and correlation and goodness-of-fit coefficients were 0.9991 and 0.9997 and 7.7 and 4.0 %, respectively. The within- and between-run precision and accuracy were evaluated and the results fell within the ranges specified. The limit of quantification was 0.1 µg/mL for both analytes, whereas limits of detection were 9.6 and 3.5 ng/mL for ketamine and norketamine, respectively. The method was applied on biological samples from a pharmacokinetic study in calves and demonstrated the suitability of the method for this application.

Multiple congenital ocular anomalies syndrome consists of several abnormalities mainly localised to the anterior segment of the eye. This condition, comprising iridal or ciliary cysts with or without iridal hypoplasia, an excessively protruding cornea (cornea globosa'), miotic pupils, retinal dysplasia, cataract, and other lesions, has been reported in several breeds and is strongly related to the silver coat colour, as a result of a dominant mutant allele at the PMEL17 locus. This report describes the macroscopic, ultrasonographic, histological and magnetic resonance imaging findings of the ocular abnormalities in a Comtois mare with multiple congenital ocular anomalies syndrome.

Objective To review the literature with regard to the use of different intravenous agents as supplements to inhalational anaesthesia in horses. The Part 2 of this review will focus in the use of opioids and a 2 -agonists. Databases used Pubmed and Web of Science. Search terms: horse, inhalant anaesthesia, balanced anaesthesia, partial intravenous anaesthesia, opioids, morphine, pethidine, butorphanol, methadone, fentanyl, alfentanil, remifentanil, sufentanil, xylazine, romifidine, detomidine, medetomidine and dexmedetomidine . Conclusions Different drugs and their combinations can be administered systemically in anaesthetized horses aiming to reduce the amount of the volatile agent while improving the recovery qualities and providing a multimodal analgesic approach. However, full studies as to whether these techniques improve cardiopulmonary status are not always available and potential disadvantages should also be considered.

Objective To compare pulmonary function and gas exchange in ponies during maintenance of anaesthesia with isoflurane or by a total intravenous anaesthesia (TIVA) technique. Study design Experimental, cross–over study. Animals Six healthy ponies weighing mean 286 (range 233–388) ± SD 61 kg, age 13 (9-16) ± 3 years. Methods The ponies were anaesthetized twice, a minimum of two weeks apart. Following sedation with romifidine [80 μg kg −1 intravenously (IV)], anaesthesia was induced IV with midazolam (0.06 mg kg −1 ) and ketamine (2.5 mg kg −1 ), then maintained either with inhaled isoflurane (F e ’Iso = 1.1 vol%) (T-ISO) or an IV infusion of romifidine (120 μg kg −1 hour −1 ), midazolam (0.09 mg kg −1 hour −1 IV) and ketamine (3.3 mg kg −1 hour −1 ) (T-TIVA). Ponies were placed in lateral recumbency. Breathing was spontaneous and Fi’O 2 60%. After an instrumentation/stabilisation period of 30 minutes, arterial and mixed venous blood samples were taken simultaneously every 10 minutes for 60 minutes and analysed immediately. Oxygen extraction ratio (O 2 ER) and venous admixture were calculated. Tidal volume (TV), minute volume (MV), respiratory rate (f R ), packed cell volume (PCV), arterial blood pressure and heart rate (HR) were measured and recorded. Data were analysed with mixed model anova (a = 0.05). Treatments were compared overall and at two selected time points (T30 and T60) using Bonferroni correction. Results Arterial and mixed venous partial pressures of O 2 and CO 2 , and TV were significantly lower and MV and f R were higher in T-TIVA compared to T-ISO. Venous admixture did not differ between treatments. O 2 ER was significantly higher in T-TIVA. Mean arterial pressure was higher and HR was lower in T-TIVA compared to T-ISO. Conclusions and clinical relevance Whilst arterial CO 2 was within an acceptable range during both protocols, the impairment of oxygenation was more pronounced with the T-TIVA evidenced by lower arterial and venous oxygen partial pressures.

To compare breathing patterns and transdiaphragmatic pressure during total intravenous (TIVA) and isoflurane anaesthesia in ponies.Experimental, cross-over study.Six healthy ponies weighing 286 (233-388) ± 61 kg, age 13 (9-16) ± 3 years.Following premedication with romifidine [80 μg kg(-1) intravenously (IV)], general anaesthesia was induced with midazolam (0.06 mg kg(-1) IV) and ketamine (2.5 mg kg(-1) IV) and maintained with either isoflurane (Fe'Iso = 1.1%) (T-ISO) or an IV combination of romifidine (120 μg kg(-1) per hour), midazolam (0.09 mg kg(-1) hour(-1)) and ketamine (3.3 mg kg(-1) hour(-1)) (T-TIVA), while breathing 60% oxygen (FIO(2)). The circumference changes of the rib cage (RC) and abdominal compartment (ABD) were recorded using respiratory ultrasonic plethysmography (RUP). Balloon tipped catheters were placed in the distal oesophagus and the stomach and maximal transdiaphragmatic pressure (Pdi max) was calculated during Mueller's manoeuvre.The breathing pattern T-ISO was more regular and respiratory rate significantly lower compared with T-TIVA. Ponies in T-TIVA showed regularly appearing sighs, which were never observed in T-ISO. Different contribution of the RC and ABD compartments to the breathing pattern was observed with a smaller participation of the RC to the total volume change during T-ISO. Transdiaphragmatic pressures (mean 13.7 ± SD 8.61 versus 23.4 ± 7.27 cmH(2) O, p0.0001) were lower in T-TIVA compared to T-ISO [corrected]. The sum of the RC and ABD circumferential changes was lower during T-TIVA compared to T-ISO (6.32 ± 4.42 versus 11.72 ± 4.38 units, p0.0001).Marked differences in breathing pattern and transdiaphragmatic pressure exist during inhalation- and TIVA and these should be taken into account for clinical estimation of anaesthetic depth.

Objective To review the literature with regard to the use of different intravenous agents as supplements to inhalational anaesthesia in horses. These drugs include lidocaine, ketamine, opioids and α 2 -agonists. The Part 1 of this review will focus in the use of lidocaine and ketamine. Databases used Pubmed & Web of Science. Search terms: horse, inhalant anaesthesia, balanced anaesthesia, partial intravenous anaesthesia, lidocaine, ketamine . Conclusions Different drugs and their combinations can be administered systemically in anaesthetized horses, with the aim of reducing the amount of the volatile agent whilst improving the recovery qualities and providing a multimodal analgesic approach. However, full studies as to whether these techniques improve cardiopulmonary status are not always available and potential disadvantages should also be considered.

Chronic progressive lymphedema (CPL) is a well-known problem in the Belgian draft horse. However, tools for clinical diagnosis have not been standardized. Therefore, the exact disease prevalence and the possible CPL risk factors have not been investigated in the Belgian breed yet. The aim of the present study was to assess a uniform CPL clinical examination method to increase diagnostic objectivity as well as to determine the occurrence and severity of lesions. Using univariate and stepwise multivariable logistic regression models, the association of factors, such as age-gender interaction, coat color and season, with CPL occurrence was examined. In this study, it was demonstrated that CPL is highly prevalent in the Belgian draft horse: 60.66% of the horses of the total sample were affected, including a large proportion of young horses (< 3 years), whereas 85.86% was affected in a subset of older horses (≥ 3 years). In the latter, the lesions were more explicit as CPL is a chronic disorder. In some horses (i.e. 14% of the yearlings), mild clinical symptoms appeared at approximately the age of one, while distinct onset of the disease occurred from the age of three onwards. The factors age-gender interaction, coat color and season, which are significantly associated with CPL occurrence, were identified and quantified. In this study, a standardized diagnostic protocol is proposed that will enhance future data collection and furthermore will offer a foundation for quantitative genetic research. Ultimately, it will help to reduce CPL occurrence in the Belgian draft horse by means of selection.

The increased incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection in equine hospitals highlights the need for infection control protocols based on optimal patient screening. In horses, the deep ventral meatus of the nasal cavity is the principal site sampled to detect MRSA. However, in humans, the anterior nares are the preferred sampling site. The objective of this study was to determine the optimal sampling location in the nasal chambers for MRSA in horses by comparing the results obtained from three different locations (the vestibulum, diverticulum and ventral meatus) in 240 hospitalised animals. Antimicrobial susceptibility testing and epidemiological typing were conducted on representative subsets of the isolates obtained. Compared to the more invasive ventral meatus sampling (relative sensitivity 68.9%; isolation rate 37.9%), vestibulum (RS 81.1%; IR 44.6%, P=0.13) and diverticulum (RS 52.3%; IR 28.8%, P=0.03) sampling were more or less sensitive, respectively. In total, 132 horses (55%) were MRSA positive with the vast majority (98.5%) carrying genotyped isolates of the livestock-associated (LA)-MRSA clonal complex (CC) 398, and only a minority (1.5%) CC8. Of the 22 MLST typed isolates, five belonged to a novel ST2197 (t011, CC398). Although 93.9% of the isolates were multi-resistant (to β-lactam, tetracycline, trimethoprim, and gentamicin)

An epidural catheter was used to provide perioperative analgesia as part of a multimodal balanced anaesthesia and analgesia in a mare undergoing a bilateral mastectomy. Despite development of severe hypoxaemia during anaesthesia, recovery from anaesthesia was uneventful. Oral administration of a NSAID combined with administration of xylazine and morphine by an epidural catheter resulted in adequate postoperative pain relief, based on assessment of physiological parameters and behaviour. Neither complications nor side effects were observed during hospitalisation.

Summary Reasons for performing study Equine joint infection is a life-threatening disorder, and confirmation of the diagnosis can be difficult. Synovial fluid biomarkers may assist the discrimination between infectious and noninfectious joint disease. Objectives This study investigates whether the immunological detection of total and enzymatically active myeloperoxidase (MPO) assists the diagnosis of joint infection in horses. Methods The following 4 sample groups were included: healthy; osteochondritis dissecans (OCD); traumatic synovitis; and culture-confirmed infected joints. Synovial fluid was analysed for total MPO by a horse-specific sandwich enzyme-linked immunosorbent assay (ELISA) and for active MPO using the specific immunological extraction followed by enzymatic detection (SIEFED) technique. Western blot analysis was performed to confirm the antibody specificity. Results Synovial fluid from infected joints contained significantly more total and active MPO than samples from healthy joints, joints affected by OCD and joints with traumatic synovitis. Cut-off values were set at 5000 and 350 ng/ml for total and active MPO, respectively, with fair sensitivity, specificity, positive and negative predictive values and likelihood ratios for infection. Correlation coefficients were reported between the total as well as the active MPO levels and the routine synovial fluid parameters, i.e. the white blood cell count, the neutrophil count and the total protein level. No correlation was observed between MPO and either the age of the horse or the joint affected. Western blotting confirmed the antibody specificity for equine MPO. Conclusions and potential relevance Synovial fluid MPO was identified as a very promising biomarker to augment the discrimination of infectious vs. noninfectious joint disease in horses. Both ELISA and SIEFED techniques can be used for its specific and rapid detection. The analysis of synovial fluid MPO can be used as a complementary test to aid in the discrimination between infectious and noninfectious joint disease, especially when the white blood cell counts and the total protein level are inconclusive.

Reasons for performing study: Dexmedetomidine has been administered in the equine as a constant-rate infusion (CRI) during inhalation anaesthesia, preserving optimal cardiopulmonary function with calm and coordinated recoveries. Inhalant anaesthetic sparing effects have been demonstrated in other species, but not in horses. Objectives: To determine the effects of a CRI of dexmedetomidine on the minimal alveolar concentration (MAC) of sevoflurane in ponies. Methods: Six healthy adult ponies were involved in this prospective, randomised, crossover, blinded, experimental study. Each pony was anaesthetised twice (3 weeks washout period). After induction with sevoflurane in oxygen (via nasotracheal tube), the ponies were positioned on a surgical table (T0), and anaesthesia was maintained with sevoflurane (expired sevoflurane fraction 2.5%) in 55% oxygen. The ponies were randomly allocated to treatment D (dexmedetomidine 3.5 mu g/kg bwt i.v. [T10T15] followed by a CRI of dexmedetomidine at 1.75 mu g/kg bwt/h) or treatment S (bolus and CRI of saline at the same volume and rate as treatment D). After T60, MAC determination, using a classic bracketing technique, was initiated. Stimuli consisted of constant-current electrical stimuli at the skin of the lateral pastern region. Triplicate MAC estimations were obtained and averaged in each pony. Monitoring included pulse oximetry, electrocardiography, anaesthetic gas monitoring, arterial blood pressure measurement and arterial blood gases. Normocapnia was maintained by mechanical ventilation. Analysis of variance (treatment and period as fixed factors) was used to detect differences between treatments (= 0.05). Results: An intravenous (i.v.) dexmedetomidine CRI decreased mean +/- s.d. sevoflurane MAC from 2.42 +/- 0.55 to 1.07 +/- 0.21% (mean MAC reduction 53 +/- 15%). Conclusions and potential relevance: A dexmedetomidine CRI at the reported dose significantly reduces the MAC of sevoflurane.

Given the significance of methicillin-resistant Staphylococcus aureus (MRSA) infections for both horses and staff in equine veterinary hospitals, protocols are required to minimise the risk of nosocomial transmission, including the screening of the skin and nasal chambers of equine patients for evidence of infection. The objective of this study was to clarify the potential existence and extent of MRSA on the skin of horses requiring long-term hospitalisation (⩾6 months). Thirty such horses were sampled at eight different locations on their skin and from their nasal chambers. MRSA was isolated from 12 animals (40%), with all sample sites testing positive on at least one occasion. Organisms were most frequently detected in the nasal chambers (relative sensitivity, 83.3%; 34.5% positive horses; isolation rate 33.3%). Skin presence was found in 30% of animals with the highest isolation rates found at the carpus (16.7%), neck, withers and croup (13.3% each). To achieve a relative screening sensitivity of >90%, at least one skin site was required in addition to nasal sampling. This evidence of skin as well as nasal reservoirs of MRSA in long-term hospitalised horses should facilitate the design of effective screening and containment protocols.

Patent ductus arteriosus (PDA) is one of the most common congenital vascular abnormalities in the dog. In veterinary medicine, surgical ligation (SL) and transarterial occlusion (TO) are two possible treatments that require general anesthesia. Two 4-month-old dogs were anesthetized for the correction of PDA, one by SL and the other by TO. Two different anesthetic and analgesic protocols were used, and were chosen to avoid potential complications. This case report describes two possible anesthetic approaches for PDA corrective surgery (SL and TO).

An electronic sensor system for urinary bladder pressure monitoring requires an imbedding into a biocompatible, flexible, and liquid-impermeable material. Poly(dimethylsiloxane) (PDMS) was selected in the present set-up as packaging material because it fulfills the abovementioned requirements. However, the surface of PDMS is hydrophobic and causes undesired interactions with salts, proteins, and cells present in urine. To reduce possible interactions of urine salts in the urinary bladder, monomers, [2-(methacryloyloxy)ethyl]-dimethyl-3-sulfopropyl-ammonium hydroxide (sulfobetaine) and 2-acrylamido-2-methylpropyl sulfonic acid, were grafted onto the surface through oxygen plasma treatment. A reduction in salt deposition between the pure PDMS and the modified PDMS was observed both in vitro (artificial urine flow over the surface) and in vivo (implants into the urinary bladder of experimental pigs). Additionally, a 10-fold reduction in salt deposition was observed in vitro due to grafting of the monomers onto the surface. These modified PDMS materials proved also to be biocompatible in cell cultures, which was further confirmed by histological screening of the bladder tissue after implantation in an in vivo pig model.

Objective To investigate the influence of a dexmedetomidine constant rate infusion (CRI) in horses anaesthetized with isoflurane. Study design Prospective, randomized, blinded, clinical study. Animals Forty adult healthy horses (weight mean 491 ± SD 102 kg) undergoing elective surgery. Methods After sedation [dexmedetomidine, 3.5 μg kg −1 intravenously (IV)] and induction IV (midazolam 0.06 mg kg −1 , ketamine 2.2 mg kg −1 ), anaesthesia was maintained with isoflurane in oxygen/air (FiO 2 55–60%). Horses were ventilated and dobutamine was administered when hypoventilation [arterial partial pressure of CO 2 > 8.00 kPa (60 mmHg)] and hypotension [arterial pressure 70 mmHg] occurred respectively. During anaesthesia, horses were randomly allocated to receive a CRI of dexmedetomidine (1.75 μg kg −1 hour −1 ) (D) or saline (S). Monitoring included end-tidal isoflurane concentration, cardiopulmonary parameters, and need for dobutamine and additional ketamine. All horses received 0.875 μg kg −1 dexmedetomidine IV for the recovery period. Age and weight of the horses, duration of anaesthesia, additional ketamine and dobutamine, cardiopulmonary data ( anova ), recovery scores (Wilcoxon Rank Sum Test), duration of recovery ( t -test) and attempts to stand (Mann–Whitney test) were compared between groups. Significance was set at p Results Heart rate and arterial partial pressure of oxygen were significantly lower in group D compared to group S. An interaction between treatment and time was present for cardiac index, oxygen delivery index and systemic vascular resistance. End-tidal isoflurane concentration and heart rate significantly increased over time. Packed cell volume, systolic, diastolic and mean arterial pressure, arterial oxygen content, stroke volume index and systemic vascular resistance significantly decreased over time. Recovery scores were significantly better in group D, with fewer attempts to stand and significantly longer times to sternal position and first attempt to stand. Conclusions and clinical relevance A dexmedetomidine CRI produced limited cardiopulmonary effects, but significantly improved recovery quality.

Pluronic® F127 is a biocompatible, injectable, and thermoresponsive polymer with promising biomedical applications. In this study, a chemically modified form, i.e., Pluronic ALA-L with tailored degradation rate, was tested as an encapsulation vehicle for osteoblastic cells. UV cross-linking of the modified polymer results in a stable hydrogel with a slower degradation rate. Toxicological screening showed no adverse effects of the modified Pluronic ALA-L on the cell viability. Moreover, high viability of embedded cells in the cross-linked Pluronic ALA-L was observed with life/death fluorescent staining during a 7-day-culture period. Cells were also cultured on macroporous, cross-linked gelatin microbeads, called CultiSpher-S® carriers, and encapsulated into the modified cross-linked hydrogel. Also, in this situation, good cell proliferation and migration could be observed in vitro. Preliminary in vivo tests have shown the formation of new bone starting from the injected pre-loaded CultiSpher-S® carriers.

Objective To examine the influence of a detomidine constant rate infusion (CRI) on cardiovascular function, isoflurane requirements and recovery quality in horses undergoing elective surgery. Study design Prospective, randomized, blinded, clinical trial. Animals Twenty adult healthy horses. Methods After sedation (detomidine, 10 μg kg−1 intravenously [IV]) and induction of anaesthesia (midazolam 0.06 mg kg−1, ketamine 2.2 mg kg−1 IV), anaesthesia was maintained with isoflurane in oxygen/air (inspiratory oxygen fraction 55%). When indicated, the lungs were mechanically ventilated. Dobutamine was administered when MAP < 70 mmHg. The horses were randomly allocated to one of two groups and throughout anaesthesia, received either a detomidine (5 μg kg−1 hour−1) (D) or saline (S) CRI, with the anaesthetist unaware of the treatment. Monitoring included end-tidal isoflurane concentration, arterial pH, PaCO2, PaO2, dobutamine administration rate, heart rate (HR), arterial pressure, cardiac index (CI), systemic vascular resistance (SVR), stroke index and oxygen delivery index ( D ˙ O2I). For recovery from anaesthesia, all horses received 2.5 μg kg−1 detomidine IV. Recovery quality and duration were recorded in each horse. For statistical analysis, anova , Pearson chi-square and Wilcoxon rank sum tests were used as relevant. Results Heart rate (p = 0.0176) and D ˙ O2I (p = 0.0084) were lower and SVR higher (p = 0.0126) in group D, compared to group S. Heart rate (p = 0.0011) and pH (p = 0.0187) increased over time. Significant differences in isoflurane requirements were not detected. Recovery quality and duration were comparable between treatments. Conclusions and clinical relevance A detomidine CRI produced cardiovascular effects typical for a2-agonists, without affecting isoflurane requirements, recovery duration or recovery quality.

Objective : To evaluate the cardiovascular effects of a preload of hydroxyethylstarch 6% (HES), preceding an epidural administration of ropivacaine 0.75% in isoflurane anaesthetized dogs. Animals : Six female, neutered Beagle dogs (mean 13.3 +/- SD 1.0 kg; 3.6 +/- 0.1 years). Study design : Randomized experimental cross-over study (washout of 1 month). Methods : Anaesthesia was induced with propofol and maintained with isoflurane in oxygen/air. All dogs were anaesthetized twice to receive either treatment HESR (continuous rate infusion [CRI] of 7 mL kg(-1) HES started 30 minutes [T-30] prior to epidural administration of ropivacaine 0.75% 1.65 mg kg(-1) at T0) or treatment R (no HES preload and similar dose and timing of epidural ropivacaine administration). Baseline measurements were obtained at T-5. Heart rate (HR), mean (MAP), diastolic (DAP) and systolic (SAP) invasive arterial pressures, cardiac output (Lithium dilution and pulse contour analysis) and derived parameters were recorded every 5 minutes for 60 minutes. Statistical analysis was performed on five dogs, due to the death of one dog. Results : Clinically relevant decreases in MAP (

Objective—To determine the accuracy of pressure plate kinetic asymmetry indices (ASIs) for diagnosis of unilateral hind limb lameness in dogs and their correlation with visual gait assessment (VGA) scores. Animals—9 healthy dogs and 16 dogs with previously diagnosed unilateral rupture of the cranial cruciate ligament and concurrent unilateral hind limb lameness. Procedures—Dogs were walked over a pressure plate to determine paw contact area (PCA), peak vertical pressure (PVP), peak vertical force (PVF), and vertical impulse (VI) of both hind limbs. An ASI was calculated for each gait variable. Simultaneously, gait was assessed visually and scored by use of a numeric rating scale (0 to 10). The ASI of each variable was tested for its usefulness in discrimination between lame and nonlame dogs and for correlation with VGA scores. Results—Sensitivity and specificity of ASIs to discriminate between lame and nonlame dogs were excellent for PVF, VI, and PCA; these values were substantially lower for ASI of PVP. Cutoff values to discriminate between lame and nonlame dogs were determined by use of ASIs for PVF, VI, and PCA; however, this could not be done for ASI of PVP. Correlations between ASIs of PVF, VI, and PCA and VGA scores were higher than correlation between the ASIs of PVP and VGA scores. Conclusions and Clinical Relevance—Results indicated that ASIs of PVF and VI determined via analysis of pressure plate measurements were reliable indicators of clinical lameness in dogs, but the ASI of PVP was not. The ASI of PCA is an interesting new variable for assessment of limb loading symmetry.

The medical records of 30 horses (18 Warmbloods, 7 draught horses, 3 other breeds and 2 of unknown origin) with chronic proliferative pododermatitis (canker) were reviewed and long-term outcome was obtained by telephone questionnaire. In 28/30 cases, the owner was the first to discover the problem. The disease was initially recognised as canker in only 5/28 cases, whereas in 10/28 cases a treatment for thrush had been continued for several months before referral. There was a similar prevalence in the fore (41) and hind (44) hooves; 13/30 horses had 4 hooves affected. Treatment consisted of surgical debridement and hoof care. Duration of hospitalisation was significantly decreased in horses receiving oral prednisolone for 3 weeks compared to those without this additional systemic treatment (mean +/- s.d. 24 +/- 5 days, n = 7 vs. 40 +/- 19 days, n = 19, respectively). Long-term follow-up ranged from 3 months to 6 years (36 +/- 22 months) and was available for 24 horses. No recurrence was reported in 10 horses. In 14 horses problems recurred within the first year, and 6 had been subjected to euthanasia for this reason specifically, whereas the others were managed by regular trimming. There was no significant association between recurrence and the number of affected hooves or the use of any systemic treatment. Horses with delayed referral because of preceding treatments had significantly more chance to develop recurrence, highlighting the need for prompt diagnosis and subsequent treatment.

Objective To investigate physiological and sedative/ immobilization effects of medetomidine or dexmedetomidine combined with ketamine in free-ranging Chinese water deer (CWD).Study design Prospective clinical trial.Animals 10 free-ranging adult Chinese water deer (11.0 +/- 2.6 kg).Methods Animals were darted intramuscularly with 0.08 +/- 0.004 mg kg(-1) medetomidine and 3.2 +/- 0.2 mg kg(-1) ketamine (MK) or 0.04 +/- 0.01 mg kg(-1) dexmedetomidine and 2.9 +/- 0.1 mg kg(-1) ketamine (DMK) If the animal was still laterally recumbent after 60 minutes of immobilization, atipamezole was administered intravenously (MK: 0.4 +/- 0.02 mg kg(-1), DMK: 0.2 +/- 0.03 mg kg(-1)). Heart rate (HR) respiratory rate (f(R)) and temperature were recorded at 5-minute intervals. Arterial blood was taken 15 and 45 minutes after initial injection. Statistical analysis was performed using Student's t-test or ANOVA. p < 0.05 was considered significant.Results Animals became recumbent rapidly in both groups. Most had involuntary ear twitches, but there was no response to external stimuli. There were no statistical differences in mean HR (MK: 75 +/- 14 beats minute(-1); DMK: 85 +/- 21 beats minute(-1)), f(R) (MK: 51 +/- 35 breaths minute(-1); DMK; 36 +/- 9 breaths minute(-1)), temperature (MK: 38.1 +/- 0.7 degrees C; DMK: 38.4 +/- 0.5 degrees C), blood gas values (MK: PaO2 63 +/- 6 mmHg, PaCO2 49.6 +/- 2.6 mmHg, HCO3- 30.8 +/- 4.5 mmol L-1; DMK: PaO2 77 +/- 35 mmHg, PaCO2 45.9 +/- 11.5 mmHg, HCO3- 31.0 +/- 4.5 mmol L-1) and biochemical values between groups but temperature decreased in both groups. All animals needed antagonism of immobilization after 60 minutes. Recovery was quick and uneventful. There were no adverse effects after recovery.Conclusion and clinical relevance Both anaesthetic protocols provided satisfactory immobilisation. There was no clear preference for either protocol and both appear suitable for CWD.

Objective To compare the cardiovascular effects of four epidural treatments in isoflurane anaesthetised dogs. Study design Prospective, randomized. experimental study. Animals Six female, neutered Beagle dogs (13.3 +/- 1.0 kg), aged 3.6 +/- 0.1 years. Methods Anaesthesia was induced with propofol (8.3 +/- 1.1 mg kg(-1)) and maintained with isoflurane in a mixture of oxygen and air [inspiratory fraction of oxygen (FiO(2)) = 40%], using intermittent positive pressure ventilation. Using a cross-over model, NaCl 0.9% (P); methadone 1% 0.1 mg kg(-1) (M); ropivacaine 0.75% 1.65 mg kg(-1) (R) or methadone 1% 0.1 mg kg(-1) + ropivacaine 0.75% 1.65 mg kg(-1) (RM) in equal volumes (0.23 mL kg(-1)) using NaCl 0.9%, was administered epidurally at the level of the lumbosacral space. Treatment P was administered to five dogs only. Cardiovascular and respiratory variables, blood gases, and oesophageal temperature were recorded at T-15 and for 60 minutes after epidural injection (T0). Results Mean overall heart rate (HR in beats minute(-1)) was significantly lower after treatment M (119 +/- 16) (p = 0.0019), R (110 +/- 18) (p < 0.0001) and RM (109 +/- 13) (p < 0.0001), compared to treatment P (135 +/- 21). Additionally, a significant difference in HR between treatments RM and M was found (p = 0.04). After both ropivacaine treatments, systemic arterial pressures (sAP) were significantly lower compared to other treatments. No significant overall differences between treatments were present for central venous pressure, cardiac output, stroke volume, systemic vascular resistance, oxygen delivery and arterial oxygen content (CaO2). Heart rate and sAP significantly increased after treatment P and M compared to baseline (T-15). With all treatments significant reductions from baseline were observed in oesophageal temperature, packed cell volume and CaO2. A transient unilateral Horner's syndrome occurred in one dog after treatment R. Conclusions and clinical relevance Clinically important low sAPs were observed after the ropivacaine epidural treatments in isoflurane anaesthetised dogs. Systemic arterial pressures were clinically acceptable when using epidural methadone.

The influence of pretreatment with ketoconazole [cytochrome P450 3A (CYP3A) + P-glycoprotein (P-gp) inhibitor], elacridar (selective P-gp inhibitor) and rifampicin (CYP3A + P-gp inducer) on oral morphine pharmacokinetics and pharmacodynamics was investigated in experimental dogs. Seven beagles were used in a four-way crossover design. Morphine hydrochloride was administered orally (2.5 mg/kg) alone (control group CON) or after pretreatment with ketoconazole (group KETO), elacridar (group ELA) or rifampicin (group RIF). Morphine plasma concentrations were analysed by liquid chromatography-tandem mass spectrometry. Sedation scores (none, mild, moderate or severe) were evaluated subjectively. Dogs were significantly (P < 0.05) more sedated after ketoconazole pretreatment. There were no significant differences between group CON and the other pretreatment groups in pharmacokinetic parameters taking both sexes into account. Sex differences were apparent in some pharmacokinetic parameters of morphine. The area under the plasma concentration time curve (AUC(0-∞) ) was significantly higher, and the total body clearance was significantly lower in male compared to female dogs in all treatment groups. Ketoconazole, rifampicin and elacridar pretreatment had no significant effects on morphine pharmacokinetics, although dogs in the ketoconazole group showed higher sedation scores.

Modern pressure plates (PP) could be an alternative to traditional force plates (FP) for quantitative equine gait analysis, thereby providing the clinician with objective data on the horse's gait while unravelling the loading of different regions of the hoof during the stance phase. The aim of this study was to determine whether a stand-alone PP allows reliable measurement of gait kinetics, compared to simultaneously recorded FP variables. Six sound Warmblood horses were walked and trotted over a combined PP and FP system for collection of a set of five valid kinetic measurements for each forelimb. A measurement was considered valid if the horse was moving in a straight line at a constant pace while gait velocity was within a preset range and the hoof fully contacted the plate surface. Significant differences between FP and PP data were seen for peak vertical force (PVF), vertical impulse (VI), time at which the PVF occurs (tPVF) and forelimb symmetry ratios (SymPVF and SymVI) (P0.05), but not for stance phase duration (ST). Nevertheless, mean agreement indices (AIs) of ST, tPVF and SymPVF and SymVI were excellent (≥ 0.92), whereas AIs of PVF and VI were moderate (≥ 0.70). The excellent agreement between PP and FP symmetry ratios confirms that observed differences between PP and FP in symmetry ratios are small (2-7%), especially when compared to the expected decrease in symmetry associated with mild lameness (20%). The results indicate that a stand-alone pressure plate can be used to measure absolute (ST) and relative (tPVF) temporal variables and loading symmetry ratios and offers equine veterinarians a mobile, cost-efficient and quick gait evaluation method for routine clinical use. However, the system cannot be used interchangeably with a force plate to measure absolute values of limb loading.

Objective To evaluate the effects of a constant rate infusion (CRI) of romifidine on the requirement of isoflurane, cardiovascular performance and recovery in anaesthetized horses undergoing arthroscopic surgery. Study design Randomized blinded prospective clinical trial. Animals Thirty horses scheduled for routine arthroscopy. Methods After premedication (acepromazine 0.02 mg kg −1 , romifidine 80 μg kg −1 , methadone 0.1 mg kg −1 ) and induction (midazolam 0.06 mg kg −1 ketamine 2.2 mg kg −1 ), anaesthesia was maintained with isoflurane in oxygen. Horses were assigned randomly to receive a CRI of saline (group S) or 40 μg kg −1 hour −1 romifidine (group R). The influences of time and treatment on anaesthetic and cardiovascular parameters were evaluated using an analysis of variance. Body weight ( t ‐test), duration of anaesthesia ( t ‐test) and recovery score (Wilcoxon Rank Sum Test) were compared between groups. Significance was set at p Results All but one horse were positioned in the dorsal recumbent position and ventilated from the start of anaesthesia. End tidal isoflurane concentrations were similar in both groups at similar time points and over the whole anaesthetic period. Cardiac output was significantly lower in horses of the R group, but there were no significant differences between groups in cardiac index, body weight or age. All other cardiovascular parameters were similar in both groups. Quality of recovery did not differ significantly between groups, but more horses in group R stood without ataxia at the first attempt. One horse from group S had a problematic recovery. Conclusions and clinical relevance No inhalation anaesthetic sparing effect or side effects were observed by using a 40 μg kg −1 hour −1 romifidine CRI in isoflurane anaesthetized horses under clinical conditions. Cardiovascular performance remained acceptable. Further studies are needed to identify the effective dose of romifidine that will induce an inhalation anaesthetic sparing effect in anaesthetized horses.

Objective To evaluate the cardiopulmonary effects of two different constant rate infusions (CRI) of dexmedetomidine (1 and 1.75 μg kg−1 hour−1) in experimental ponies. Animals Six healthy ponies (mean 306 ± SD 71 kg, 7.0 ± 1.6 years). Study design Prospective, randomized, experimental study. Methods After premedication with intravenous (IV) dexmedetomidine (3.5 μg kg−1), anaesthesia was induced (T0) with ketamine (2.2 mg kg−1 IV) and midazolam (0.06 mg kg−1 IV) and maintained with isoflurane (F e ′ISO 1.50%) in 55% oxygen for 150 minutes. Normocapnia was maintained using artificial ventilation. Three ponies received dexmedetomidine CRIs of 1 and 1.75 μg kg−1 hour−1 from T30 to T60 and T90 to T120 respectively. In the other three ponies, the order of the doses was reversed. Continuous monitoring included pulse oximetry, electrocardiography, anaesthetic gas monitoring, arterial and central venous pressures. Cardiac ouput (LiDCO technique) was measured and arterial and venous bloods taken every 15 minutes. Cardiac index (CI), systemic vascular resistance (SVR), arterial and venous oxygen content (CaO2, CvO2) and oxygen delivery ( D ˙ O2) were calculated. Analysis of variance with separate models for each CRI rate was used to detect differences between values obtained at the end of the CRI and their respective baseline values. A mixed model with these differences as response variable, pony as random effect and treatment and period as fixed effects was applied to find differences between the two CRIs (α = 0.05 for all analyses). Results Heart rate (HR), CI, CaO2, CvO2 and D ˙ O2 decreased significantly, while significant increases were found in SVR, systolic arterial pressure and right atrial pressure with both infusion rates. No differences were found between the two dexmedetomidine CRI rates. Conclusions and clinical relevance Although significant, cardiopulmonary effects of the dexmedetomidine CRIs in isoflurane anaesthetized ponies were small, without differences between the two dose rates.

Summary Reasons for performing study: Standard methods for culturing equine synovial fluid (SF) are often unrewarding. Evidence-based information on the relative efficiency of different systems used for optimisation of isolation of microorganisms from equine SF is lacking. Objectives: To compare the results of different culture systems performed in parallel on SF samples from horses clinically diagnosed with synovial sepsis. Methods: Synovial fluid specimens were collected between February 2007 and October 2008 from all horses admitted to a referral hospital that were clinically diagnosed with synovial sepsis and from control horses. Synovial fluid samples were cultured in parallel by: 1) direct agar culture (DA); agar culture after: 2) lysis-centrifugation pretreatment (LC); 3) conventional enrichment (CE); 4) combined LC/CE; or 5) blood culture medium enrichment using an automated system (BACTEC 9050). Results: Ninety SF samples from 82 horses were included, together with 40 control samples. Seventy-one of 90 samples (79%) were culture-positive by using blood culture medium enrichment (BACTEC), which was significantly higher compared to all other methods. BACTEC enrichment was never negative while any of the other methods was positive. Although agar culture following LC and/or CE resulted in a slightly higher number of positive samples compared to DA, this difference was not significant. All control samples were culture negative by the 5 different techniques. Although the majority of samples containing isolates recovered without enrichment, culture results after BACTEC enrichment were available on the same day as for agar culture with or without LC (19/23 samples), while CE postponed recovery by at least one day in 20/23 samples. Conclusion: Blood culture medium enrichment is superior to other techniques for isolation of bacteria from SF of horses. The use of an automated system allows enrichment without substantially postponing recovery of microorganisms. Potential relevance: The efficient and fast isolation of microorganisms from infected SF by the BACTEC system allows for rapid susceptibility testing and a more appropriate antibiotic treatment.