OBJECTIVE:To evaluate the effect of perioperative electroacupuncture (EA) on intraoperative analgesic requirements in dogs undergoing tibial tuberosity advancement (TTA) surgery. STUDY DESIGN:Prospective, randomised, blinded, controlled clinical study. ANIMALS:A group of 29 client-owned dogs diagnosed with cranial cruciate ligament rupture that underwent TTA surgery. METHODS:Dogs were treated with EA at predefined acupuncture points (LI-4, ST-36, LIV-3, SP-6 and GB-34) perioperatively as additional analgesia (group EA, n = 14) or were allocated to the control group (group C, n = 15). All dogs were anaesthetised with a standardised protocol including methadone, dexmedetomidine, propofol and ketamine. The intraoperative delivery of sevoflurane and fentanyl was guided in response to signs of nociception by a purpose-designed flowchart, by the same anaesthetist who was blinded to treatment group. A Wilcoxon rank sum test was applied for the fentanyl consumption analysis. Heart rate, mean arterial blood pressure and end-tidal sevoflurane were descriptively analysed between groups for specific time points. A p value < 0.05 was considered significant. RESULTS:The EA group needed significantly less fentanyl with 0.7 (0-2.7) μg kg-1 hour-1 administered versus 2.0 (1.2-5.5) μg kg-1 hour-1 in group C (p = 0.031). Fifty percent of the EA group was not administered a fentanyl bolus, whereas all dogs in group C required at least one bolus. CONCLUSIONS AND CLINICAL RELEVANCE:Perioperative EA reduced mean fentanyl consumption by more than 60% in dogs undergoing TTA surgery.

OBJECTIVE:To compare macrocirculatory effects of haemorrhage followed by fluid resuscitation with Plasma-Lyte A (PA) or Ringer's Lactate (RL) crystalloid solution in dogs under sevoflurane anaesthesia. STUDY DESIGN:Single-centre, randomised, blinded, experimental study. ANIMALS:A group of 12 adult, healthy, intact, purpose-bred Beagle dogs. METHODS:Dogs were instrumented under sevoflurane anaesthesia. Heart rate, cardiac output (CO), and mean arterial blood pressure (MAP) were measured at baseline, after removing 30 mL kg-1 of blood over 15 minutes [hypovolaemia (HV)], and after each of two boluses (B1 and B2) of either 10 mL kg-1 PA or RL administered intravenously over 10 minutes. Data were compared using a linear mixed model with group and time points as fixed factors and dogs as a random factor, and corrections for multiple comparisons. A p value < 0.05 was considered significant. RESULTS:There were no significant differences between treatments. Compared with HV, CO increased in both groups at B1: RL [0.57 (0.23-0.91) L minute-1 (estimated difference ± 95% confidence interval), p < 0.001] and PA [0.37 (0.03-0.7) L minute-1, p = 0.030], and at B2: RL [0.88 (0.54-1.2), p < 0.001] and PA [0.66 (0.23-0.91) L minute-1, p < 0.001]. The increase of MAP in RL was significant at B1 [15 (1-29) mmHg, p < 0.028] and B2 [16 (2-30) mmHg, p < 0.016] compared with HV, while MAP in PA was not significantly different at B1 [3 (-11 to 17) mmHg, p = 0.995] and B2 [4 (-9 to 18) mmHg, p = 0.943] compared with HV. CONCLUSIONS AND CLINICAL RELEVANCE:In this small experimental study, both fluids tested led to a clinically significant increase in CO. No consistent increase in MAP was observed across fluid types. Alterations in MAP should not be used as a surrogate for flow variables to assess fluid responsiveness.

OBJECTIVE:To compare the effects of haemorrhage and subsequent fluid resuscitation with Plasma-Lyte A (PA) or Ringer's Lactate (RL) on buccal microcirculation. STUDY DESIGN:Single-centre, randomised, blinded, experimental study. ANIMALS:A group of 12 adult, healthy, intact, purpose-bred Beagle dogs. METHODS:In sevoflurane anaesthetised Beagle dogs, a sidestream dark field (SDF) imaging device was positioned on the buccal mucosa to evaluate microcirculatory variables, which included perfused De Backer density (pDBD) and proportion of perfused vessels. Videos were recorded at baseline, following the removal of 30 mL kg-1 of blood to induce hypovolaemia (HV), and after each 10 mL kg-1 intravenous fluid bolus (B1 and B2) according to the assigned treatment group. Data were compared between groups and over time using a linear mixed model with group and time point as fixed and dogs as random factors. Post hoc multiple comparisons were performed with Sidak's corrections. A p value < 0.05 was considered significant. RESULTS:The haemorrhage resuscitation model resulted in significant changes in microcirculation over time. In group RL, pDBD was significantly more reduced compared with group PA at HV [RL: 1.3 (0.9-1.8) n mm-1 (median ± 95% confidence interval), PA: 2.3 (1.6-2.7) n mm-1, p = 0.004] and B2 [RL: 2 (1.7-2.7), PA: 3.3 (2.7- 4.2), p < 0.001]. Proportion of perfused vessels was also more reduced in group RL compared with group PA at HV [RL: 57 (53-77)%, PA: 78 (69-93)%, p < 0.001] and B2 [RL: 72 (65-96)%, PA: 85 (77-99)%, p = 0.012]. CONCLUSIONS AND CLINICAL RELEVANCE:Dogs administered PA showed fewer changes in pDBD and proportion of perfused vessels values after haemorrhage and resuscitation with 20 mL kg-1 PA compared with those administered RL. Due to the small sample size these preliminary findings warrant further research.

Dogs infected with the cardiopulmonary nematode Angiostrongylus vasorum are at high risk to die because of the associated bleeding pathologies, which remain poorly understood. Given their central role in immune surveillance and signaling, we analyzed transcriptomic profiles from (i) A. vasorum-infected dogs presenting with hypocoagulability (Infhypo; n = 5), (ii) infected dogs with normal coagulation values (Infnorm; n = 5), and (iii) uninfected controls (UC; n = 12). Alongside classical hematology and coagulation parameters, including rotational thromboelastometry (ROTEM), we generated a global transcriptomic profile of circulating blood cells, enabling the identification of differentially expressed genes following infection. Fibrinogen levels were significantly lower in Infhypo than in Infnorm dogs. All Infhypo dogs showed out-of-range prothrombin times. Matrix metalloprotease transcripts were strongly upregulated among infected dogs, regardless of their coagulation status, which might amplify vascular disruption and inflammation. Analysis of downregulated transcripts in infected dogs compared to UC indicated a loss of endothelial integrity, especially at the level of the lungs, and of inflammatory processes contributing to fibrinolysis and coagulopathies. Endothelial injury is a known trigger of disseminated intravascular coagulation (DIC) and consumption of coagulation factors, which could explain the observed coagulation disorders induced by A. vasorum infection. The multifaceted alterations observed in hematologic and coagulation parameters, ROTEM, and transcriptomic profiles of A. vasorum-infected dogs point to a dynamic and evolving disruption of hemostatic balance. While some animals show signs of early compensatory hypercoagulability, others seem to progress toward a state consistent with DIC, marked by factor consumption, endothelial dysfunction, and impaired fibrinogen-dependent clotting.

To compare the use of postoperative analgesia for mastectomy, 44 dogs were randomly allocated to either the Splash treatment group (group A) or the Transverse Abdominis Plane block treatment group (TAP, group B). Following intramuscular (IM) premedication with pethidine (4 mg kg−1) and acepromazine (0.01 mg kg−1), anesthesia was induced with intravenous (IV) propofol and maintained with isoflurane by an anesthetist (DC) who was unaware of the treatment. In group A, ropivacaine 0.5% (2 mg kg−1) was administered prior to surgical wound closure. In group B, ropivacaine 0.5% (0.8–1 mg kg−1 per point) was administered by ultrasound-guided TAP block with two injection points per treated body side. At the end of the surgery, all dogs received pethidine (4 mg kg−1 IM), meloxicam (0.2 mg kg−1 IV), and acepromazine (0.005 mg kg−1 IV). The animals’ pain was assessed by the anesthetist, who remained unaware of the treatment type used, via the Short Form of the Glasgow Composite Pain Scale. When the pain scores were ≥6, methadone (0.2 mg kg−1 IV) and gabapentin (10 mg kg−1 per oral) were started. When the pain score remained ≥ 6, ketamine (1 mg kg−1 subcutaneously) was administered. The dogs in the TAP block group had lower postoperative pain scores 3–12 h after anesthesia administration was terminated and required significantly less rescue analgesia.

A 5.5-year-old, male domestic ferret (Mustela putorius furo) diagnosed with insulinoma was presented for a dental procedure under general anaesthesia. In insulinoma patients, it is essential to avoid hypoglycaemia. In other species, constant rate infusion of dexmedetomidine has been reported to sustain adequate blood glucose by inhibiting insulin secretion. Following premedication with butorphanol and midazolam, anaesthesia was induced with alfaxalone and maintained with sevoflurane and dexmedetomidine constant rate infusion (0.25-0.5 mu g/kg/h). Serial blood glucose measurements demonstrated an initial rapid surge, increasing to hyperglycaemic levels even after cessation of dexmedetomidine constant rate infusion. After a delayed recovery with blood glucose decreasing over time, the ferret fully recovered and remained euglycaemic until discharge. This case report highlights the rapid rise of blood glucose shortly after starting dexmedetomidine. Dexmedetomidine constant rate infusion might not be necessary for prednisolone-treated ferrets to avoid hypoglycaemia, but the anaesthetic-sparing and analgesic effects could still be useful to provide balanced anaesthesia in insulinoma patients.

ABSTRACT Background Endotoxaemia is a significant cause of morbidity and mortality in equids due to perfusion impairment and possible destruction of the glycocalyx. Objectives To evaluate our hypothesis that endotoxaemia induces changes in global cardiovascular and haematologic parameters and compromises glycocalyx integrity, evidenced by an early rise in plasma shedding products. Study design In vivo experiments Methods In a prospective, randomised, controlled experimental trial, endotoxaemia was induced with E. coli B55:O5 LPS 30 ng kg−1 over 30 min IV in six healthy adult horses ventilated with oxygen supplemented with isoflurane. Standard cardiovascular variables were recorded and calculated, and leucocyte counts, lactate, heparan sulphate and syndecan‐1 concentration were determined at baseline (B) before endotoxin and at 0, 30, 60 and 120 min after endotoxin. Data were analysed using mixed models and adjusted by Tukey‐Kramer (SAS Enterprise Guide Software 7.1). Results After endotoxin (120 min), a significant increase (p ≤ 0.05) in cardiac index (43 ± 9 vs. 80 ± 15 mL kg−1 min−1, p < 0.01), in oxygen delivery index (8 ± 3 vs. 17 ± 4 mL min−1 kg−1, p <0.001), in pulse pressure variation (8 ± 3 vs. 17 ± 4, p < 0.01) and in lactate (1.55 ± 0,9 vs. 4.4 ± 0.52 mmol L−1, p < 0.0001) occurred with a decrease in systemic vascular resistance index (247 ± 87 vs. 83 ± 20 dynes s kg cm−5, p < 0.001), diastolic arterial blood pressure (69 ± 14 vs. 38 ± 5 mmHg; p < 0.001), and leucocyte counts (5.6 ± 1.3 vs. 1.5 ± 0.3 G l−1, p < 0.0001). No changes in the glycocalyx degradation products could be found. Conclusion Short‐term experimental endotoxaemia under isoflurane induced anticipated cardiovascular changes but did not alter glycocalyx shedding products in this study.

Endotoxemia often leads to microcirculatory derangement. In six sevoflurane anaesthetized Beagle dogs, we investigated the effects of 1 mg/kg of Escherichia coli lipopolysaccharide endotoxin intravenous and blood pressure (mean arterial pressure of 65 mmHg versus 85 mmHg) on microcirculation assessed on buccal mucosa using side stream dark field microscopy. Dogs were afterwards resuscitated with fluids and noradrenaline. We investigated dose requirements of noradrenaline with or without dexmedetomidine. Microcirculatory parameters, and markers of sepsis (cardiac output, mixed venous oxygen saturation, carbon dioxide gap, and lactate) were analysed before endotoxemia, after endotoxemia, after a 30 mL/kg of Ringer's acetate fluid bolus, and during noradrenaline +/- dexmedetomidine infusion, after a second fluid bolus, and a second time after vasopressor treatment in a cross-over fashion. Endotoxemia and mean arterial pressure had no statistically significant effect on microcirculation; however, endotoxemia resulted in a decrease in cardiac output. Dexmedetomidine neither improved microcirculation nor reduced noradrenaline requirements.

This case report outlines complications associated with ear flush procedures in two cats. The first case, a female Domestic Short Hair cat, aged 8 years and weighing 3.9 kg, presented with signs of Horner's syndrome and right-sided facial paralysis. Magnetic resonance imaging revealed bilateral otitis media and right-sided bulla osteolysis. Under general anaesthesia with sevoflurane, a bilateral myringotomy and ear flush was performed. After flushing of the right ear, there was significant swelling on the right side of the head, extending to the left side and with oropharyngeal oedema, which made visualization of the trachea impossible. It was decided not to attempt tracheal extubation. Intravenous (IV) clemastine and topical mannitol were administered to treat a possible drug reaction and decrease oedema, respectively. The cat was transferred to intensive care unit and maintained under general anaesthesia. The lungs were mechanically ventilated, and antimicrobials and steroids were administered IV. The subsequent day, as the swelling and oedema had resolved, successful extubation was performed, and the patient was discharged from the clinic. The second case was a spayed female Domestic Short Hair cat, aged 9 years, weighing 2.4 kg and with a history of ear disease. It had recently developed symptoms of right-sided peripheral vestibular syndrome. Under anaesthesia with sevoflurane, magnetic resonance imaging revealed bilateral otitis media with bulla osteitis. The cat's trachea was extubated after ear flush and myringotomy, followed shortly after by emergency orotracheal reintubation owing to oropharyngeal soft tissue swelling causing upper airway obstruction. The cat was administered glucose and phenylephrine topically and dexamethasone IV. The airway was nebulized with diluted epinephrine. Anaesthesia recovery and extubation were possible a few hours later. The cat recovered in an oxygen cage in the intensive care unit and was administered antimicrobials, maropitant and butorphanol IV and closely monitored overnight. The cat was discharged from the clinic the next day.

A 2‐year‐old, male, neutered dachshund was presented for further investigation of a progressive chronic cough. For endoscopy, general anaesthesia was induced with butorphanol, propofol and ketamine and maintained with sevoflurane in O 2 and air, while the dog was breathing spontaneously. Following bronchoalveolar lavage, the dog's peripheral haemoglobin oxygen saturation (SpO 2 ) decreased from 99% to less than 94%. Severe acute respiratory distress syndrome was suspected based on decreased saturation and chest radiography, and mechanical ventilation using positive end‐expiratory pressure of 5–10 cmH 2 O was started. SpO 2 /FiO 2 and later PaO 2 /FiO 2 were used to assess oxygenation continuously and intermittently. Once SpO 2 levels constantly remained above 97%, slow weaning from both high FiO 2 levels and mechanical ventilation was started. At the end of the weaning period, both SpO 2 /FiO 2 and PaO 2 /FiO 2 were greater than 250 (% and mmHg, respectively), and the dog had successfully recovered. The dog was discharged 2 days later in a good clinical state.

BACKGROUND:Microcirculation is the essential link between macrocirculation and cellular metabolism. OBJECTIVES:To test our hypotheses that microcirculation variables will show a heterogeneous flow pattern during experimental endotoxaemia, and that fluid therapy and noradrenaline (NA) infusion will normalise altered microcirculation variables. STUDY DESIGN:In vivo experiments. METHODS:Six healthy adult horses were anaesthetised with dexmedetomidine, ketamine, and diazepam and were mechanically ventilated under isoflurane anaesthesia. Endotoxaemia was induced with 30 ng kg-1 Escherichia coli lipopolysaccharide intravenously. One hundred and twenty minutes later fluid bolus and noradrenaline (NA) infusion were administered to produce normotension. Pulse rate (PR) and mean arterial blood pressure (MAP) were measured and microcirculation variables were obtained by side-stream darkfield technique (de Backer density (DBD), perfused de Backer density (PDBD), proportion of perfused vessels, microvascular flow index (MFI), heterogeneity index (HI)), laser Doppler flowmetry (blood flow) and white light spectrometry (tissue oxygen saturation (tSO2)) in sublingual, jejunal and genital area. Measurements were obtained at baseline, after endotoxin, at 60 and 120 min and during the normotensive phase. Data were analysed by mixed model variance analysis and Tukey-Kramer. RESULTS:The PPV decreased significantly over time by 30% (p < 0.001) at the jejunum. MFI decreased from baseline to ET60 and from baseline to ET120 in sublingual and genital mucosa (2.9 vs. 1.4, p < 0.001 and 2.8 vs. 1.9, p < 0.01), respectively. The sublingual HI increased from baseline to ET60, ET120 and NA (0.1 vs. 0.9, p = 0.02; vs. 0.6, p = 0.01; vs. 0.3, p = 0.01), respectively. The genital HI increased from baseline to ET120 (0.2 vs. 1.1, p ≤ 0.01) and NA (0.16 vs. 0.53, p < 0.05, respectively). Moderate agreement between observers for MFI assessment was present (kappa = 0.4). The PR significantly increased, and MAP significantly decreased from baseline over time. MAIN LIMITATIONS:The obtained data could be influenced by secretions, pressure artefacts, the experience of the examiner and the sampling location. Blood flow was not quantified and there was no control group. CONCLUSIONS:Overall, short-term experimental endotoxaemia did negatively alter MFI and HI; however, it did not alter tSO2, blood flow, DBD, PDBD or proportion of perfused vessels. Intravenous fluid therapy and NA did not restore MFI and HI to baseline values.

IntroductionIntra-operative hypotension is a common complication of surgery under general anesthesia in dogs and humans. Computer-controlled closed-loop infusion systems of norepinephrine (NE) have been developed and clinically applied for automated optimization of arterial pressure (AP) and prevention of intra-operative hypotension in humans. This study aimed to develop a simple computer-controlled closed-loop infusion system of NE for the automated control of the mean arterial pressure (MAP) in dogs with isoflurane-induced hypotension and to validate the control of MAP by the developed system.MethodsNE was administered via the cephalic vein, whereas MAP was measured invasively by placing a catheter in the dorsal pedal artery. The proportional-integral-derivative (PID) controller in the negative feedback loop of the developed system titrated the infusion rate of NE to maintain the MAP at the target value of 60 mmHg. The titration was updated every 2 s. The performance of the developed system was evaluated in six laboratory Beagle dogs under general anesthesia with isoflurane.ResultsIn the six dogs, when the concentration [median (interquartile range)] of inhaled isoflurane was increased from 1.5 (1.5–1.5)% to 4 (4–4)% without activating the system, the MAP was lowered from 95 (91–99) to 41 (37–42) mmHg. In contrast, when the concentration was increased from 1.5 (1.0–1.5)% to 4 (4–4.8)% for a 30-min period and the system was simultaneously activated, the MAP was temporarily lowered from 92 (89–95) to 47 (43–49) mmHg but recovered to 58 (57–58) mmHg owing to the system-controlled infusion of NE. If the acceptable target range for MAP was defined as target MAP ±5 mmHg (55 ≤ MAP ≤65 mmHg), the percentage of time wherein the MAP was maintained within the acceptable range was 96 (89–100)% in the six dogs during the second half of the 30-min period (from 15 to 30 min after system activation). The median performance error, median absolute performance error, wobble, and divergence were − 2.9 (−4.7 to 1.9)%, 2.9 (2.0–4.7)%, 1.3 (0.8–1.8)%, and − 0.24 (−0.34 to −0.11)%·min−1, respectively. No adverse events were observed during the study period, and all dogs were extubated uneventfully.ConclusionThis system was able to titrate the NE infusion rates in an accurate and stable manner to maintain the MAP within the predetermined target range in dogs with isoflurane-induced hypotension. This system can be a potential tool in daily clinical practice for the care of companion dogs.

Sepsis of Gram negative bacterial origin results in lipopolysaccharide-induced endotoxemia. This often leads to acute kidney injury (AKI) and its recognition remains a challenge and delays treatment. As renal damage occurs before a rise in serum creatinine is detected, new early biomarkers of kidney injury need to be explored. The aim of this study was to determine changes in serum parameters of renal function and urine biomarkers of renal injury. This was a descriptive study. Endotoxemia was induced intravenously in six anaesthetized Beagles (T1). To achieve normotension, dogs received fluids (T2), followed by a continuous infusion of noradrenaline and dexmedetomidine or 0.9% NaCl (T3). Ten minutes later, the dogs received fluids (T4) and noradrenaline and dexmedetomidine or 0.9% NaCl in a crossover manner (T5). At each timepoint, blood and urine were collected for serum creatinine, urea, symmetric dimethylarginine, urine protein/creatinine (UPC) ratio, urine neutrophilgelatinase-associated lipocalin (U-NGAL), U-NGAL/creatinine ratio, urine clusterin (U-clusterin) and U-clusterin/ creatinine ratio. Data were analyzed using a mixed-effect model taking into account time and stage of veterinary AKI (VAKI). Three of six dogs had a VAKI stage >1; one with anuria and elevated creatinine. Serum creatinine (P < 0.001), U-NGAL/creatinine ratio (P = 0.01) and U-clusterin/creatinine ratio increased over time (P < 0.01). The UPC ratio (mean (range) 0.68 (0.35-2.3) versus 0.39 (0.15-0.71) P < 0.01) and U-NGAL (3164 pg/mL (100-147,555) versus 100 (100-14,524), P = 0.01) were higher in VAKI stage >1 versus stage 0, respectively. Endotoxemia induced VAKI stage >1 in half of the dogs. Repeated measurement of selected parameters could detect AKI early.

Recommendations for intraperitoneal (IP) and incisional (INC) administration of local anaesthetics after visceral surgery exist, but evidence is scarce. This prospective, randomized, blinded, controlled, clinical trial compared postoperative pain in dogs undergoing major abdominal surgery. Sixteen client-owned dogs were anaesthetized with a standardized balanced protocol including opioids and received either 2 mg/kg ropivacaine IP (0.27 mL/kg) and a 1 mg/kg INC splash (0.13 mL/kg) or equal volumes of saline. Influence of the treatment on heart rate (HR) and postoperative pain was assessed using the Short Form of the Glasgow Composite Pain Scale (GCPS-SF), a dynamic interactive visual analogue scale (DIVAS) and mechanical nociceptive threshold testing (MNT). Data was tested with mixed ordinal regression and log linear mixed models for 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 h after extubation. Rescue analgesia was given to 3/8 dogs after ropivacaine and 0/8 dogs after saline. GCPS-SF and MNT were not different between groups. DIVAS was slightly higher after ropivacaine (odds increased by 5.44 (confidence interval (CI) 1.17–9.96, p = 0.012)), and HR after ropivacaine was 0.76 * that after saline (CI 0.61–0.96, p = 0.02) with no effect of time (p = 0.1). Undiluted ropivacaine IP and INC was not beneficial for postoperative analgesia.

Introduction:The aim of this retrospective study was to determine whether there is an association between leukoreduction of packed red blood cell (pRBC) units and reduction of clinically observed transfusion reactions (TR), particularly febrile non-haemolytic transfusion reactions (FNHTR), and better outcomes in dogs. Secondary aims were to evaluate the effects of other factors suspected to influence transfusion reaction frequency or survival, including crossmatching, use of immunosuppressive drugs, and age and number of the blood products being administered.Materials and methods:Medical data on dogs transfused with leukocyte-reduced (LR) and non-leukocyte-reduced (N-LR) pRBC units at the Animal Hospital Zürich, University of Zürich, Switzerland between January 1, 2007, and December 17, 2018 were searched. Before 2014, only N-LR blood were transfused. After 2014, both LR and N-LR blood were available.Results:A total of 339 canine patients were transfused with 413 pRBC units; 30.5% (126/413) were LR units and 69.5% (287/413) were N-LR. Data collected from medical records was analyzed using univariate and multivariate logistic regression. In the present study, TR occurred in 19.8% of pRBC units (25/126) with LR and in 17.7% (51/287) of pRBC with N-LR; p > 0.05. FNHTR occurred in 6.3% of pRBC units (8/126) with LR and in 4.5% (13/287) of those with N-LR; p > 0.05. There was no correlation between the occurrence of TR and discharge from hospital (p > 0.05). Crossmatching, immunosuppressive therapy, and age of the blood product were not associated with the frequency of TR; p > 0.05 for all. The duration of survival days was not related to the number of transfusions dogs received.Discussion:In the present study, the leukocyte-depletion of transfused pRBC units was not associated with fewer TR nor to fewer FNHTR compared to N-LR units. Discharge of dogs from hospital was not dependent on the occurrence of TR.

This letter reports the cardiovascular complications that developed in a cat after a 3 mL kg–1 fluid bolus of Ringer’s acetate during sevoflurane general anaesthesia. We highlight the possible side effects of acetate containing intravenous (IV) crystalloid fluids administered as a rapid bolus. Fluid therapy is routinely administered to veterinary patients during general anaesthesia, and IV fluid boluses are administered to increase preload, stroke volume and possibly improve tissue perfusion ( Boysen and Gommeren, 2021 Boysen S.R. Gommeren K. Assessment of volume status and fluid responsiveness in small animals. Front Vet Sci. 2021; 8630643 Crossref PubMed Scopus (3) Google Scholar ). To avoid unnecessary fluid administration, which may increase morbidity and mortality, the fluid responsiveness of an individual can be assessed with a preload challenge. This can be a mini IV isotonic fluid bolus of 3–5 mL kg–1, administered over 1–5 minutes ( Boysen and Gommeren, 2021 Boysen S.R. Gommeren K. Assessment of volume status and fluid responsiveness in small animals. Front Vet Sci. 2021; 8630643 Crossref PubMed Scopus (3) Google Scholar ).

Introduction:In recent years ketamine has increasingly become the focus of multimodal emergency management for epileptic seizures. However, little is known about the effect of ketamine on brain metabolites in epileptic patients. Magnetic resonance spectroscopy (MRS) is a non-invasive technique to estimate brain metabolites in vivo. Our aim was to measure the effect of ketamine on thalamic metabolites in idiopathic epileptic (IE) dogs using 3 Tesla MRS. We hypothesized that ketamine would increase the glutamine-glutamate (GLX)/creatine ratio in epileptic dogs with and without antiseizure drug treatment, but not in control dogs. Furthermore, we hypothesized that no different responses after ketamine administration in other measured brain metabolite ratios between the different groups would be detected.Methods:In this controlled prospective experimental trial IE dogs with or without antiseizure drug treatment and healthy client-owned relatives of the breeds Border Collie and Greater Swiss Mountain Dog, were included. After sedation with butorphanol, induction with propofol and maintenance with sevoflurane in oxygen and air, a single voxel MRS at the level of the thalamus was performed before and 2 min after intravenous administration of 1 mg/kg ketamine. An automated data processing spectral fitting linear combination model algorithm was used to estimate all commonly measured metabolite ratios. A mixed ANOVA with the independent variables ketamine administration and group allocation was performed for all measured metabolites. A p < 0.05 was considered statistically significant.Results:Twelve healthy control dogs, 10 untreated IE and 12 treated IE dogs were included. No significant effects for GLX/creatine were found. However, increased glucose/creatine ratios were found (p < 0.001) with no effect of group allocation. Furthermore, increases in the GABA/creatine ratio were found in IEU dogs.Discussion:MRS was able to detect changes in metabolite/creatine ratios after intravenous administration of 1 mg/kg ketamine in dogs and no evidence was found that excitatory effects are induced in the thalamus. Although it is beyond the scope of this study to investigate the antiseizure potential of ketamine in dogs, results of this research suggest that the effect of ketamine on the brain metabolites could be dependent on the concentrations of brain metabolites before administration.

Feline overpopulation raises issues concerning health, ecology, economy, and ethics. Procedures to limit overpopulation should carefully address animal welfare, efficiency, costs, and feasibility. Vasectomy in unowned cats is suggested as preferable to standard neutering as it maintains male sexual behaviour which may induce ovulation and pseudopregnancy in intact females and may prevent immigration of other males. Vasectomy is not performed routinely because it is fastidious, time consuming and requires more material than standard neutering. We describe epididymectomy as an alternative. In a first experiment, we analysed semen, testosterone, behaviour and pain in six experimental cats before and after epididymectomy, and after castration two months later. Excised tissues were analysed histologically. Testosterone concentrations did not differ significantly between intact and epididymectomised animals but were significantly different after castration. Sexual behaviour and testicular spermatogenesis persisted after epididymectomy, but with a marked drop in the semen count after 7 days. The Glasgow pain scores did not differ significantly after epididymectomy and castration. In a subsequent experiment, 20 privately owned cats were epididymectomised and castrated immediately afterwards, to analyse the learning curve and perioperative complications. The time required for an epididymectomy was significantly shorter than for castration. The study confirms that epididymectomy is quicker and less invasive than castration, it is associated with minimal risks and post-operative pain while easy to learn and inexpensive. Further field studies are required to test its efficiency for feline feral population control or in other species such as in bears, lions or deer, where infertility is required and castration not wanted.