Background: The inclusion of dexmedetomidine (DEX) within a balanced general anaesthesia protocol is effective in improving the clinical outcome and recovery quality of anaesthesia in horses. This study aimed to determine the pharmacokinetic profile of DEX following repeated subcutaneous (SC) administration at 2 µg/kg every 60 min till the end of the procedure in comparison to intravenous constant rate infusion (CRI) at 1 µg/kg/h in anaesthetized horses undergoing diagnostic procedures up to the end of the diagnostic procedure. Results: In the CRI and SC groups DEX maximum concentrations (C_max) were 0.83 ± 0.27 ng/mL and 1.14 ± 0.71 ng/mL, respectively, reached at a time (T_max) of 57.0 ± 13.4 min and 105.5 ± 29.9 min. Mean residence time to the last measurable concentration (MRT_last) was 11.7 ± 6.2 and 55.8 ± 19.7 min for the CRI group and SC groups, respectively. The apparent elimination half-life was 18.0 ± 10.0 min in the CRI group and 94.8 ± 69.8 min for the SC group, whereas the area under the curve (AUC_0-last) resulted 67.7 ± 29.3 and 83.2 ± 60.5 min*ng/mL for CRI and SC group, respectively. Clearance was 16.26 ± 8.07 mL/min/kg for the CRI group. No signs of adverse effects were recorded in both groups. Conclusions: The pharmacokinetic profile of DEX following repeated SC administration in anaesthetized horses was comparable to intravenous CRI administration during the intranaesthetic period and beneficial during the recovery phase from general anaesthesia. The SC route could be considered as an alternative to CRI for improving the recovery quality of equine patients undergoing general anaesthesia.

Baboons’ management requires chemical restraint. Three intramuscular sedative protocols in captive hamadryas baboons (Papio hamadryas) undergoing health-check and male vasectomy were compared. Animals were assigned to TZD_G (n = 17; tiletamine/zolazepam 3 mg/kg + dexmedetomidine 20 μg/kg), KDM_G (n = 23; ketamine 6 mg/kg + dexmedetomidine 30 μg/kg + methadone 0.2 mg/kg), or MDM_G (n = 9; midazolam 2 mg/kg + dexmedetomidine 60 μg/kg + methadone 0.2 mg/kg). Propofol was titrated intravenously for anaesthetic induction and maintenance. Sedation time and quality and cardiopulmonary parameters were recorded. Atipamezole (TZD_G 0.2 mg/kg, KDM_G 0.3 mg/kg, MDM_G 0.6 mg/kg) and flumazenil (MDM_G 0.02 mg/kg) were administered intramuscularly post-procedure. Recovery time and quality were recorded. Data were reported as median (interquartile range) or regression coefficient (B). Sedation was deepest in TZD_G (20, 20–20; KDM_G 20, 19–20; MDM_G 19, 15–20; p = 0.017). MDM_G had a significantly higher heart rate (B = 10.27, p = 0.001), respiratory rate (B = 9.09, p < 0.001), and lower end-tidal carbon dioxide (B = −3.00, p = 0.03) than TZD_G, while KDM_G had a lower respiratory rate than TZD_G (B = −3.67, p = 0.02) and a higher temperature (B = 1.66 p = 0.001). TZD_G showed the longest recovery (minutes: 19, 11.5–30; KDM_G: 6, 4–12; MDM_G: 4, 2.5–5; p < 0.001), while MDM_G the best recovery (0, 0–0; TZD_G: 9, 6–12; KDM_G: 0, 0–6; p < 0.001). TZD produced deepest sedation but bad recovery; KDM offered optimal sedation and recovery, and cardiopulmonary stability; MDM provided lighter sedation and excellent recovery.

High induction doses of propofol (PPF) may cause adverse effects. Co-induction protocols can reduce doses and enhance the beneficial profile of each drug. This study compared the induction quality, clinical, and echocardiographic effects of two rapid co-inductions in healthy, unpremedicated dogs. Baseline cardiorespiratory and echocardiographic variables were recorded. Dogs randomly received rapid intravenous PPF (2.2 mg/kg) with either dexmedetomidine (3 µg/kg) (PROPODEX; n = 12) or butorphanol (0.4 mg/kg) (PROPOBUT; n = 12). Induction quality, additional PPF dose, intubation time, cardiorespiratory parameters (2, 5, 10, 15, 20 min), and recovery quality were recorded. A second echocardiography was performed 5 min after induction. Induction quality was significantly higher in PROPODEX, with significantly lower additional PPF requirements and shorter intubation time. In PROPODEX, heart rate significantly decreased from baseline and was significantly lower than PROPOBUT, while arterial blood pressures significantly increased in PROPODEX and decreased in PROPOBUT from baseline. PROPOBUT significantly reduced left ventricular (LV) diastolic volumes and increased E/A ratio, while PROPODEX significantly increased LV systolic diameter and volumes, and significantly decreased fractional shortening. Recovery was significantly faster and better in PROPODEX. PROPOBUT preserved cardiac function but caused hypotension. PROPODEX provided superior induction and recovery quality, and cardiorespiratory stability, with only mild systolic function depression.

The study aimed to compare the quality of perioperative analgesia, the motor block duration, and the effects on main cardiovascular parameters of dexmedetomidine (1 μg/kg/nerve block) or magnesium sulphate (2 mg/kg/nerve block) as adjuvants to 0.3% ropivacaine for sciatic and saphenous nerves block in dogs undergoing tibial plateau leveling osteotomy (TPLO). Dogs randomly received perineural dexmedetomidine-ropivacaine (D group), magnesium sulphate-ropivacaine (M group), or ropivacaine (C group). Fentanyl was administered in case of intraoperative nociception. Postoperative pain was assessed using the Short Form-Glasgow Composite Measure Pain Scale (SF-GCMPS) and VAS scale. The duration of motor blockade and intra- and postoperative cardiovascular parameters were also recorded. Group M required significantly more fentanyl than D group ( p = 0.04). Group M had a significantly higher SF-GCMPS score than group C at 4 (p = 0.002) and 5 h after extubation (p = 0.01), and a significantly higher VAS score than group D at 3 h after extubation (p = 0.03), and at 4 h if compared to group C (p = 0.009). No significant differences regarding the duration of motor blockade were detected between groups (p = 0.07). The heart rate was significantly lower in group D than in M and C groups intraoperatively and during the first 1.5 h post extubation. The addition of dexmedetomidine or magnesium sulphate as adjuvants to perineural ropivacaine did not improve the quality of perioperative analgesia and did not prolong the motor blockade in dogs undergoing sciatic and saphenous nerves block for TPLO surgery.

Radiofrequency ablation (RFA) and pulsed radiofrequency (PRF) are non-pharmacological techniques employed in humans for chronic pain, but their veterinary application is unexplored. This pilot study evaluated clinical effects of RFA and PRF in twenty-four horses with chronic distal forelimb lameness. Ultrasound-guided RFA (N = 8; 60–90 °C, 2–8 min) or PRF (N = 16; 42 °C; 12 min) was applied to palmar digital nerves. Lameness was scored (American Association of Equine Practitioners scale) at baseline and monthly for six months (T1-T6). At T2, partial- and non-responders in both groups received PRF. Complications and return to previous work were recorded. At T2, the PRF group had significantly lower lameness scores (1, 0–3) than the RFA group (3, 2–4; p < 0.001) and significantly improved from baseline (3, 2–4; p < 0.01). RFA caused more complications (N = 6) than PRF (N = 1; p < 0.001), including increased lameness and allodynia. Sixteen horses (RFA: N = 7; PRF: N = 9) were retreated at T2. Overall, lameness significantly improved from T2 (2, 0–4) to T6 (0, 0–3; p < 0.001). At T6, 83% (19/23) of horses resumed previous work. RFA was ineffective and caused complications, whereas PRF appeared safer and more effective. Two PRF treatments yielded better outcomes with fewer side effects and may help manage lameness and associated pain for up to six months.