Epameinondas Loukopoulos

Locoregional anaesthesia is vital in modern equine veterinary practice. It effectively manages acute pain and may reduce the anaesthetic requirements and adverse effects associated with general anaesthesia. This review summarises the currently described local anaesthetic techniques used in horses, with emphasis on epidural approaches, peripheral nerve blocks, and fascial plane techniques. The relevant literature was identified through searches of PubMed, Web of Science, and Scopus databases. The review discusses the pharmacological properties of commonly used local anaesthetics, differences between short- and long-acting agents, and the potential role of adjuvants in prolonging analgesia. In addition, the available evidence regarding ultrasound-guided and nerve stimulator-guided techniques is presented, including their applications in thoracic, abdominal, and reproductive procedures. Attention is given to recently described fascial plane blocks and to the growing use of ultrasound guidance for improving anatomical identification and needle placement. The available evidence suggests that locoregional anaesthesia can contribute to multimodal analgesia in horses while potentially reducing perioperative systemic analgesic requirements. However, the clinical evidence supporting several techniques remains limited, and further controlled studies are required to evaluate their efficacy, safety, and reproducibility under clinical conditions.

Phimosis is rarely reported in cats and involves the inability to exteriorize the penis through an absent or abnormally narrowed preputial orifice. This case report describes the clinical presentation, surgical management, and outcome of two male domestic shorthair kittens with suspected congenital type II phimosis. Both cats presented with recurrent stranguria and dysuria, preputial swelling, urine pooling or dribbling, a markedly stenotic preputial orifice, and penile–preputial adhesions. In Case 1, cystic struvite urolithiasis was also identified; treatment included cystotomy and ventrally performed modified preputial urethrostomy because of extensive adhesions, penile hypoplasia, and limited penile mobility. In Case 2, adhesions were limited to the distal penis and were released, allowing circumferential preputioplasty. No postoperative complications occurred. Clinical signs resolved, and normal urination was recorded during available follow-up, which was 12 months in Case 1 and 2 months in Case 2. The congenital origin was suspected based on early onset of clinical signs but could not be definitively confirmed. These cases suggest that selected feline type II phimosis cases can be managed successfully by tailoring surgery to anatomical abnormalities, using ventral-modified preputial urethrostomy when adhesions and penile hypoplasia restrict mobilization, or circumferential preputioplasty when adhesions are limited distally.

This case series describes the management of two critically ill animals with pneumothorax of different etiologies. The first case involves a five year old male mixed breed dog that sustained multiple thoracic bites. The dog was presented with severe respiratory distress, subcutaneous edema, pale mucous membranes, tachycardia and crackling respiratory sounds. Thoracic radiographs revealed pneumothorax, pneumomediastinum, atelectasis and flail chest due to rib fractures. Initial stabilization included oxygen therapy, thoracocenteses, intravenous fluids, analgesics and antibiotics. Due to persistent air accumulation, autologous blood patch pleurodesis (ABPP) was performed, resulting in initial clinical improvement. However, respiratory deterioration necessitated the placement of a thoracostomy tube with continuous suction. Forty-eight hours later pneumothorax was dissolved, and the dog was discharged. Two years post discharge, the dog remains asymptomatic. The second case involves a 10 month old female cat with chronic respiratory distress due to trauma. Clinical examination revealed abdominal breathing, paradoxical movement and dysmporphy of the thoracic wall. Radiographs were indicative of diaphragmatic hernia. Surgical repair via midline laparotomy was performed, and thoracocentesis was conducted to manage the pneumothorax. However, due to severe postoperative dyspnea and persisted air accumulation in the thorax, repeated thoracocenteses, thoracostomy tube placement and ultimately autologous blood patch were deemed necessary. Suspicion of a ruptured pulmonary bulla led to an exploratory thoracotomy, during which a pulmonary defect was identified and resected. Unfortunately, the cat succumbed due to presumed prolonged hypoxia during surgery. These cases highlight the complexity of managing pneumothorax in small animals. The series underscores the need for a combination of classic pneumothorax management techniques with more recently described options, such as autologous blood pleurodesis. It also emphasizes the importance of advanced diagnostic imaging in managing such patients and the variable prognoses as well.

The objective of the present study was to apply supervised Machine Learning to predict severe complications after equine orchiectomy. A dataset of 612 cases of orchiectomies in stallions was used for the development of a computational model, among which in 8.5% of cases severe complications (colic, continued stallion-like behaviour, evisceration, funiculitis, haemorrhage, and scrotal infection) were diagnosed post-orchiectomy. Three supervised Machine Learning tools were employed: Logistic Regression (12 different models evaluated), Random Forest (64 models), and Gradient Boosting (8 models). For the prediction of the development of severe complications post-orchiectomy, Logistic Regression was the tool that produced the best discrimination measures, where accuracy, precision and recall were 0.9134, 0.8391, and 0.9133, respectively. The results of the analysis for SHapley Additive exPlanations values for the impact of the independent variables in the prediction of the development of complications indicated that (a) the age of the horse and (b) the surgical technique employed were the two variables that mostly influenced the prediction outcome, findings that were unambiguous in the models developed by any Machine Learning tool. The findings of this study indicate that computational models could be used as adjunct tools to support clinical decisions in the peri-operative management of horses.

The objectives of this work were (i) to evaluate the incidence of complications in male horses after orchiectomy performed in the field, i.e., away from a veterinary hospital, (ii) to describe the post-operative complications that occurred in these animals and (iii) to study the potential predictors for the development of such complications. This study involved 612 animals, on which orchiectomy was performed. The operative part of the study was carried out by one of three experienced veterinary surgeons. Standard pre-operative procedures were followed. Orchiectomy was performed using one of three principal surgical techniques, open, semi-closed or closed, and hemostasis was achieved by means of one of the various procedures, specifically the use of the Henderson instrument, the use of the Reimer emasculator, the ligation of the testicular artery or combinations thereof. In cases of reported complications, these were verified and identified appropriately. At least one (any) post-operative complication was recorded in 145 horses (23.7%). The most frequently observed complication was scrotal swelling/seroma formation, which was observed in 130 animals (21.2% of all animals; 89.7% of animals with at least one (any) complication). Another six different complications were observed, specifically colic, continued stallion-like behavior, evisceration, funiculitis, hemorrhage and scrotal infection. The median age of horses with complications was significantly older than that of animals with no complications: 11 versus 9 years. Animals in which the open technique was applied developed post-operative complications more frequently (30.1% of animals thus operated); further, complications were observed more frequently in animals on which operations were performed by using the Henderson instrument (84.6% of animals) versus animals on which any of the various other procedures were applied (22.4%). In multivariable analysis, the following predictors emerged for the development of complications: the surgical technique employed, the procedure applied for hemostasis, older animal age, and heavier animal bodyweight. The findings confirm that orchiectomy in stallions, even when performed in field conditions, is, in general, a safe procedure. The identification of predictors suggests that veterinarians should take additional care when planning to operate on animals at higher risk or when using surgical approaches that increase the potential for the development of complications.

The administration of lidocaine as part of multimodal analgesia in dogs undergoing ovariohysterectomies demonstrates variable analgesic efficacy. The aim of this prospective, double–blinded clinical study was to evaluate the effectiveness of lidocaine 2% irrigation on the ovarian suspensory ligament, followed by localised massage, in achieving sufficient intraoperative analgesia. Thirty-eight female dogs were randomly divided to two groups and received either a splash block of 0.5 ml lidocaine 2% on each ovarian suspensory ligament (GL) or an equal volume of saline (GNS). All dogs were premedicated with dexmedetomidine (5 μg·kg⁻¹) and buprenorphine (20 μg·kg⁻¹) intramuscularly and meloxicam (0.2 mg·kg⁻¹) subcutaneously. Anaesthesia was induced with propofol and maintained with isoflurane. The surgical procedure was initiated after an adequate depth of anaesthesia was achieved. Heart rate (HR), respiratory rate (f_R) and mean arterial pressure (MAP) were continuously monitored. Fentanyl (2 μg·kg⁻¹) was administered as rescue analgesia in case of a 30% increase in HR, f_R, or MAP, compared to their values before manipulation of the ovaries. Data were analysed using a mixed model for repeated measures ANOVA and Pearson’s Chi-Square test. The need for rescue analgesia differed significantly between the two groups (p < 0.0005). In GNS, 89.47% (17/19) of the dogs required rescue analgesia, compared to 10.53% (2/19) of the dogs in GL. The relative risk of rescue for the GNS compared to the GL was approximately 8.5. In conclusion, intraoperative analgesia during ovariohysterectomies in dogs can be enhanced using a lidocaine 2% splash block combined with massage of the ovarian suspensory ligament.

Dexmedetomidine is an a₂-agonist commonly used in veterinary practice. Occasionally, the administered dose of dexmedetomidine may result in insufficient sedation, and an additional dose or drug may be required. The sedative effects of seven different drugs administered at subsequent time points after an initial, insufficient dose of dexmedetomidine were evaluated. Seven adult cats participated in this crossover, blind, randomised study. The groups consisted of two consecutive doses of dexmedetomidine (15 + 10 μg/kg) (DD) or a dose of dexmedetomidine (15 μg/kg) followed by either NS 0.9% (DC-control group), tramadol 2 mg/kg (DT), butorphanol 0.2 mg/kg (DBT), buprenorphine 20 μg/kg (DBP), ketamine 2 mg/kg (DK), or midazolam 0.1 mg/kg (DM). Sedation was evaluated using the Grint sedation scale. In all groups, atipamezole was administered at the end of the evaluation, and recovery was assessed using the Lozano and Sams recovery scales. The DC and DM groups exhibited minimal sedative effects. The maximum sedative effect was observed in the DD and DK groups, while sedation in the DD and DK groups was significantly higher compared to the DC group. Recovery in all groups was uneventful, except in the DM group, where it was prolonged and difficult, although no statistically significant difference was detected. Therefore, insufficient sedation with dexmedetomidine can be enhanced by a subsequent dose of dexmedetomidine, ketamine, or butorphanol, whereas the addition of midazolam reduces sedation and prolongs recovery.

The administered dose of dexmedetomidine may occasionally fail to produce the anticipated sedative effects. Therefore, a subsequent dose or administration of another sedative may enhance sedation; however, patient safety may be affected. The safety of seven different drugs administered at the following time point after an insufficient dose of dexmedetomidine was evaluated in a crossover, blind, experimental study that included six healthy adult cats. All cats received an initial dose of dexmedetomidine and a subsequent dose of either dexmedetomidine (Group DD), NS 0.9% (DC), tramadol (DT), butorphanol (DBT), buprenorphine (DBP), ketamine (DK), or midazolam (DM). Animal safety was assessed using repeated blood gas analysis and measurement of electrolytes, glucose, cardiac troponin I, and creatinine to evaluate cardiac, respiratory, and renal function. The median values of creatinine, cardiac troponin I, pH, partial pressure of carbon dioxide, potassium, and sodium did not change significantly throughout the study. Heart rate was significantly decreased in all groups after administration of the drug combinations, except for in the DK group. Respiratory rate decreased significantly after administration of the initial dose of dexmedetomidine and in the DBP and DM groups. The partial pressure of oxygen, although normal, decreased significantly after the administration of dexmedetomidine, whereas the median concentration of glucose increased significantly following the administration of dexmedetomidine. The results of our study suggest that the drug combinations used did not alter the blood parameters above normal limits, while cardiac and renal function were not compromised. Therefore, a safe level of sedation was achieved. However, the administration of dexmedetomidine reduced the partial pressure of oxygen; thus, oxygen supplementation during sedation may be advantageous. Additionally, the increase in glucose concentration indicates that dexmedetomidine should not be used in cats with hyperglycaemia, whereas the decrease in haematocrit suggests that dexmedetomidine is not recommended in anaemic cats.