Maropitant has been proposed as an adjunct for pain relief in dogs undergoing surgeries like ovariohysterectomy (OVH), but its effectiveness has not yet been definitively proven. This study aimed to assess the intraoperative analgesic effect of intravenously administered maropitant citrate at a constant rate infusion through monitoring parasympathetic tone activity in female dogs undergoing OVH. Thirty healthy females of various breeds, with an average age of 3.8 ± 2.7 years, an average weight of 16.75 ± 10.68 kg, were randomly assigned to two treatment groups. The group receiving maropitant (G_Maro, n = 15) was given a 1 mg kg⁻¹ maropitant bolus intravenously (IV), followed by a continuous infusion of 100 mcg kg⁻¹ min⁻¹. The lidocaine group (G_Lido, n = 15) received a 2 mg/kg lidocaine IV bolus, with subsequent infusion at 50 mcg kg⁻¹ min⁻¹. Cardiorespiratory variables and the PTA index were evaluated at 11 anesthetic time points. Overall, cardiovascular variables such as Heart Rate (HR) and systolic arterial pressure (SAP) significantly decreased during anesthesia induction in the G_Maro (p = 0.0001; p = 0.01, respectively) and in G_Lido (p = 0.01). Differences between groups during induction were observed in HR (p = 0.03), SAP (p = 0.04), and mean arterial pressure (MAP) (p = 0.03). MAP showed significant changes from baseline at the start of surgery and during clamping in both G_Maro (p = 0.03) and G_Lido (p = 0.003). Regarding ventilatory variables—pulse oximetry (SpO₂), respiratory rate (RR), inspired oxygen fraction (FiO₂), end-tidal CO₂ (EtCO₂)—no group differences were found, but RR (G_Maro; p = 0.001, G_Lido; p = 0.0001) and SpO₂ (G_Maro; p = 0.004, G_Lido; p = 0.04) differed significantly from baseline due to the controlled clinical setting. During anesthesia maintenance, end-tidal isoflurane (ET_Iso) increased significantly in the G_Lido (p = 0.009), with no difference between groups (p = 0.94). Finally, only the PTA energy variable showed a significant decrease in the G_Maro (p = 0.0006), and a significant difference in this parameter was observed during right ovarian pedicle manipulation between groups (p = 0.02). In conclusion, continuous intravenous infusion of maropitant citrate at 100 mcg kg⁻¹ h⁻¹ effectively reduced the sympathetic response related to nociception, similar to lidocaine, in healthy female dogs undergoing OVH.

Objectives: To evaluate a modified ovariohysterectomy (OHE) technique performed by a single person and compare it with the conventional method based on time efficiency, trauma, and postoperative pain.Methods: In a prospective, randomized, experimental study, 18 healthy, large, deep-chested, mixed-breed intact female dogs were randomly allocated to conventional (n = 9) and instrument shank-assisted (n = 9) groups. On the basis of video recordings, the various surgical step durations were analyzed: total surgery time (TST), pedicle intervention time (PIT), suspensory release time (SRT), shanking time (ShT), clamping time (ClpT), ligating time (LigT), and closure time (CT). The Glasgow composite pain scale short-form (GCMPS-SF), university of Melbourne pain scale (UMPS), and Visual Analogue Scales (VAS) were used to measure pain. C-reactive protein (CRP) fluctuation was also investigated. These evaluations were completed before and 6, 24, 48, and 72 h postoperatively.Results: Instrument shank-assisted OHE was less time-consuming than conventional OHE (p= 0.005), improved PIT by 30.7% (6.44 min for both pedicles,p= 0.014), and correlated strongly with TST (ρ= 0.862,p= 0.003 and ρ = 0.955,p= 0.000, respectively). The two method’s surgical step durations were also TST = 47.40 ± 9.9 vs. 34.70 ± 6.7 min, PIT = 20.96 ± 5.78 vs. 14.52 ± 3.73 min, SRT = 78.97 ± 69.10 vs. ShT = 20.39 ± 8.18 s (p= 0.035), ClpT = 50.66 ± 45.04 vs. 63.55 ± 37.15 s (p= 0.662), LigT = 12.82 ± 3.37 vs. 8.02 ± 3.11 min (p= 0.005), and CT = 16.40 ± 4.5 vs. 11.60 ± 2.5 min (p= 0.013), respectively. While both techniques inflicted pain on the animals, the novel approach resulted in a reduction of pain at T6 (GCMPS-SF,p= 0.015 and VAS,p= 0.002), T24 (UMPS,p= 0.003), and T48 (GCMPS-SF,p= 0.015 and UMPS,p= 0.050). Both methods exhibited a peak in CRP level after 24 h, which subsequently returned to baseline after 48 h. However, the shank-assisted method demonstrated a significantly lower reduction in CRP level at the 48-h compared to the other group (p = 0.032).Conclusion: Instrument shank-assisted technique permitted ovarian removal without an assistant, less damage to animals and reducing its time when compared to a conventional technique, and resulting in an alternative that causes less surgical stress and fatigue. Further research with a larger population size is required to determine the serum CRP levels as an alternative pain biomarker.

To evaluate the sensory-motor profile and physiological effects of epidural diphenhydramine (DPH) in sheep and to compare it with lidocaine. Randomized, blinded, crossover trial with ≥ 2-week intervals between treatments. A group of eight healthy adult male Zel sheep [24.0 ± 4.6 kg (mean ± standard deviation)]. Lumbosacral epidural injections of DPH at doses of 1 (0.5%), 2 (1.0%), 3 (1.5%), or 4 (2.0%) mg kg^-1 (0.2 mL kg^-1) or lidocaine 2% at 4 mg kg^-1 (0.2 mL kg^-1) were performed. Sensory blockade was assessed by needle-prick testing, and motor blockade was assessed by the degree of ataxia and ability to stand. Heart rate (HR), respiratory rate (f_R), and temperature were monitored. Sensory and motor blockade outcomes were analyzed using Kruskal-Wallis and Wilcoxon signed-rank tests with significance set at p < 0.05. Epidural DPH produced rapid-onset sensory and motor blockade in sheep (3-4 minutes) with dose-dependent effects; 2-3 mg kg^-1 yielded predominantly sensory blockade with minimal motor impairment, whereas 1 mg kg^-1 resulted in incomplete and inconsistent effects. At 4 mg kg^-1, DPH produced significantly prolonged sensory blockade compared with lidocaine [median (minimum-maximum): 126 (103-162) versus 86 (69-104) minutes; p < 0.001], while producing a shorter motor blockade [58 (48-63) versus 94 (71-129) minutes; p < 0.001], yielding a sensory-to-motor ratio of 2.2. HR, f_R, and temperature remained within normal limits across treatments (p > 0.05), and no adverse effects were observed during the 3-month follow-up. Epidural DPH (2-4 mg kg^-1) produces dose-dependent, predominantly sensory blockade with minimal motor impairment in sheep while maintaining stable physiological variables.