Controversy continues to surround the use of opioids in equine anaesthesia, with variable effects reported. This blinded clinical study aimed to investigate the influence of a low-dose fentanyl continuous rate infusion (CRI) on isoflurane requirements, parasympathetic tone activity (PTA), and anaesthetic parameters in horses during general anaesthesia. All of the twenty-two horses included in the research underwent a standard anaesthetic protocol. Eleven horses in the fentanyl group (Group F) received a loading dose of fentanyl at 6 µg/kg, followed by a CRI of 0.1 µg/kg/min during anaesthesia. A further 11 horses in the control group (Group C) received equivalent volumes of normal saline. Anaesthetic parameters and PTA index were recorded during anaesthesia. The achieved mean fentanyl plasma concentration was 6.2 ± 0.83 ng/mL. No statistically significant differences between groups were found in isoflurane requirements, MAP values, and mean dobutamine requirements. However, horses in Group F required a significantly lower dose of additional ketamine to maintain a sufficient depth of anaesthesia. Significantly higher PTA values were found in the fentanyl group. Further research is warranted to determine the limitations of PTA monitoring, and the influence of various anaesthetics on its values.

A cockerel ( Gallus gallus domesticus ) was presented for lameness investigation. A CT scan of the left leg and a bone marrow biopsy were planned. Both procedures were performed under general anaesthesia and, before the biopsy was performed, a sciatic nerve block was achieved with levobupivacaine 0.5% (0.75 mg/kg), aided by an electrical nerve locator. The nerve was located through a lateral approach, with a motor response to stimulation similar to that described in mammals. The efficacy of the block was assessed as satisfactory during the procedure. Postoperatively, the pain was subjectively assessed, but no pain scales were employed, as none are validated for birds. No iatrogenic complications occurred; therefore, this nerve block could be considered as a part of a multimodal approach to perioperative pain management.

Spinal arachnoid diverticulum is a fluid-filled dilation within the subarachnoid space that can result in compressive myelopathy, prompting investigation into optimal surgical management and outcomes. This retrospective study reviewed clinical records of dogs treated surgically between January 2021 and July 2025, including 11 cases that met the criteria of chronic progressive para- or tetraparesis, MRI-confirmed diagnosis, and use of a standardized surgical technique. All dogs underwent dorsal laminectomy followed by durotomy, durectomy, and microsurgical dissection of adhesions performed by the same surgeon, with optical magnification and specialized instruments to ensure consistency. The condition was more common in males, with French Bulldogs overrepresented (n = 6); lesions were thoracolumbar in small breeds and cervical in the single large-breed dog. Short-term outcomes, assessed one month postoperatively, showed neurological improvement in all but one dog. These findings suggest that the described microsurgical approach is feasible and associated with favorable short-term neurological recovery in most cases. However, the absence of long-term follow-up limits definitive conclusions, and further studies are needed to evaluate sustained outcomes.

Different blood gas analyzers are used in equine practice. Every machine needs to be validated, as they have not been designed for use in horses. The aim of this study was to compare the newly marketed GEM5000 machine to the formerly validated epoc machine for blood gas analysis in horses. In this prospective, non-blinded, comparative laboratory analyzer study, 43 equine blood samples were analyzed on both analyzers and values were compared between the two machines via Lin’s concordance analysis, Passing–Bablok regression analysis and Bland–Altman plots. Duplicate measurements were conducted on the GEM5000 machine to evaluate precision. The GEM5000 failed to achieve the required precision for tHb, Hct and iCa²⁺, but achieved acceptable precision for all other parameters. Concordance correlation analysis revealed poor correlation for Na⁺, Cl⁻, iCa²⁺, K⁺, Hct and tHb, while there was an at least moderate agreement for all other parameters. Passing–Bablok regression revealed significant constant bias for pCO₂, pO₂, Cl⁻, and iCa²⁺ and significant proportional bias for pCO₂, iCa²⁺ and SO₂. Bland–Altman analysis revealed significant systematic bias for Na⁺, Cl⁻, iCa²⁺, K⁺, Hct, tHb and SO₂. This study shows that while precision of the GEM5000 is good, values should not be used interchangeably with data obtained from other blood gas analyzers.