To describe the ultrasonographic anatomy of the neck region in dogs and to determine the feasibility of an injection targeted to the cervical plexus. Prospective cadaveric study. A group of six mixed-breed mesocephalic dog cadavers. Cadavers were assigned to a size category according to body weight (small, ≤10 kg; medium, 10.1-24 kg; large, > 24.1 kg) and placed in lateral recumbency. A linear probe was placed over the wing of the atlas perpendicular to the spine and slid caudally to identify the transverse process of the fourth cervical vertebra. A 22 gauge, 70 mm spinal needle was introduced in-plane and advanced in a dorso-ventral direction, reaching the cervical fascia (CF). According to the size category, 2.5 mL, 5 mL or 10 mL of 0.15% methylene blue was injected within the CF and between the intertransversarius ventralis and longus colli muscles. Each cadaver was injected bilaterally. Staining of the second (C2), third (C3) and fourth (C4) cervical ventral branches was assessed by anatomical dissection. Each size category included two cadavers: 8 kg and 10 kg in the small category; 15 kg and 19 kg in the medium category; and 26 kg and 37 kg in the large category. Nerve staining resulted only from injection within the CF. In all cadavers, 100% of the ventral rami of the second (12/12), third (12/12) and fourth (12/12) cervical nerves were stained circumferentially for > 2 cm. In the smallest cadaver, the dye reached the atlas cranially. The described injection within the CF stained the cervical plexus and appears a feasible locoregional technique in dogs.

A 3‐month‐old female Cocker Spaniel was presented for investigation of a V/VI left basilar heart murmur and diagnosed with a double‐chambered right ventricle. Atenolol was prescribed for 3 months before surgical correction of the congenital anomaly, combining cutting balloon and high‐pressure balloon (CB‐HPB) dilation. A few days before the intervention, the dog showed signs of right‐sided congestive heart failure and it was treated with furosemide, benazepril/spironolactone and pleural effusion were drained. During CB‐HPB dilation, cardiac index and systemic arterial blood pressure suddenly decreased on two occasions probably secondary to a dynamic right ventricular outflow tract obstruction. Cardiac arrest occurred and cardiopulmonary resuscitation was unsuccessful.

To compare the cranial epidural spread of contrast medium following lumbosacral (LS) versus sacrococcygeal (SCo) injection in feline cadavers and determine whether the SCo approach is noninferior to the LS approach when equivalent volumes are injected. Prospective, randomized, cadaveric, noninferiority study. A group of 28 feline cadavers greater than 6 months old. In 26 cadavers, LS or SCo epidural injections were performed; two cadavers administered intrathecal injections for comparison. Three volumes of nonionic iodinated contrast medium diluted with saline and warmed to 35 °C were consecutively injected epidurally: 0.015 (volume 1), 0.03 (volume 2), 0.015 (volume 3) mL cm^-1 of occipital-coccygeal length; approximately 0.2, 0.4, and 0.2 mL kg^-1). Fluoroscopic epidurography assessed cranial spread after each injection. Cranial spread was quantified as the number of vertebrae containing contrast, and circumferential spread was defined as dorsal, ventral, and bilateral distribution. A predefined noninferiority margin for SCo injectate spread of two vertebral segments caudal to LS injectate spread was set. A linear mixed-effects model including injected volume, epidural approach, and their interaction as fixed effects and cadaver as a random effect compared cranial spread. Noninferiority of the SCo approach relative to the LS approach was shown after volume 3. After volumes 1 to 2, median cranial spread was similar between approaches (median difference = 0 vertebrae), but the 95% confidence interval included the predefined noninferiority margin. Increasing injected volume resulted in greater cranial epidural spread regardless of approach (p < 0.0001). Intravascular contrast contamination occurred in 61.5% (LS) and 69.2% (SCo) of injections (p = 0.688). With equivalent injection volumes, the SCo approach results in cranial epidural spread similar to the LS approach in feline cadavers, with noninferiority only after volume 3. The SCo approach may represent an alternative to LS epidural injection in cats.

Dexmedetomidine improves pulmonary function in dogs and humans, but evidence in horses is scarce. This study evaluated dexmedetomidine infusion on oxygenation and respiratory mechanics in anesthetized horses. Twenty horses undergoing elective surgery were included in a prospective, non-randomized, observational study. Horses received either lidocaine alone (1.3 mg/kg over 15 min, then 3 mg/kg/hour; LIDO) or combined with dexmedetomidine (1.75 μg/kg over 15 min, then 1.75 μg/kg/hour; DL). Respiratory mechanics, gas exchange, and cardiovascular variables were recorded at baseline, post-loading, and after 30, 60, and 90 min. Data were analyzed using mixed-effects linear models with horse as a random effect and time and treatment and their interaction as fixed effects (p ≤ 0.05). Peak inspiratory pressure increased over time with both treatments but was lower with DL at 90 min (−1.26 mmHg, p = 0.046). There was no evidence that arterial oxygen pressure or oxygenation ratio improved over time with DL (p > 0.75). Shunt fraction did not significantly change over time or between treatments (Wald χ² = 4.77, p = 0.85). Heart rate with DL decreased from baseline (p ≤ 0.001) but remained higher than LIDO overall (p = 0.001). Dexmedetomidine infusion showed no benefit on oxygenation or respiratory mechanics in anesthetized horses.

Four entire male sugar gliders (Petaurus breviceps) belonging to the same colony were presented for elective orchiectomy. After clinical examination, dexmedetomidine (120 μg/kg) in combination with ketamine (5 mg/kg) were administered subcutaneously (SC). Once righting and pedal withdrawal reflexes were lost, ringer lactate solution, enrofloxacin and meloxicam were administered SC and a bilateral intratesticular block with lidocaine 0.25% was performed. Heart, respiratory rates and pulse oximetry values were recorded every minute. Onset of sedation, additional use of isoflurane, duration of anaesthesia, duration of surgery, time of recovery after atipamezole administration, quality of recovery and time of food intake were recorded. Postoperative assessment (posture, level of activity, vocalisation, response to manipulation, attention to the surgical wound) was performed hourly until discharge, five hours after surgery. Dexmedetomidine in combination with ketamine provided adequate short-lasting anaesthesia for castration in 3 out of 4 sugar gliders. One sugar glider needed additional isoflurane administration to perform orchiectomy. No perioperative additional analgesia was needed in any sugar glider.