While the current tools to assess canine postoperative pain using physiological and behavioural parameters are reliable, an objective method such as the parasympathetic tone activity (PTA) index could improve postoperative care. The aim of the study was to determine the utility of the PTA index in assessing postoperative analgaesia. Thirty healthy bitches of different breeds were randomly allocated into three groups for analgaesic treatment: the paracetamol group (GPARAC, n = 10) received 15 mg/kg b.w., the carprofen group (GCARP, n = 10) 4 mg/kg b.w., and the meloxicam group (GMELOX, n = 10) 0.2 mg/kg b.w. for 48 h after surgery. GPARAC was medicated orally every 8 h, while GCARP and GMELOX were medicated intravenously every 24 h. The PTA index was used to measure the analgaesia–nociception balance 1 h before surgery (baseline), and at 1, 2, 4, 6, 8, 12, 16, 20, 24, 36, and 48 h after, at which times evaluation on the University of Melbourne Pain Scale (UMPS) was made. The baseline PTA index was 65 ± 8 for GPARAC, 65 ± 7 for GCARP, and 62 ± 5 for GMELOX. Postoperatively, it was 65 ± 9 for GPARAC, 63 ± 8 for GCARP, and 65 ± 8 for GMELOX. No statistically significant difference existed between baseline values or between values directly after treatments (P = 0.99 and P = 0.97, respectively). The PTA index showed a sensitivity of 40%, specificity of 98.46% and a negative predictive value of 99.07%. Our findings suggest that the PTA index measures comfort and postoperative analgaesia objectively, since it showed a clinical relationship with the UMPS.

Opioids are considered the gold standard to manage acute or chronic or mild to severe pain. Tramadol is a widely prescribed analgesic drug for dogs and cats; it has a synthetic partial agonism on μ-opioid receptors and inhibits the reuptake of norepinephrine and serotonin. However, the biotransformation and resultant metabolites differ between species and depend on cytochrome P450 interactions. Dogs mainly produce the inactive N-desmethyl tramadol metabolite, whereas cats exhibit an improved antinociceptive effect owing to rapid active O-desmethyltramadol metabolite production and a longer elimination half-life. Tapentadol, a novel opioid with dual action on μ-receptors and noradrenaline reuptake inhibitory activity, is a promising option in dogs, as it is less reliant on metabolic activation and is unaffected by cytochrome polymorphisms. Although scientific evidence on the analgesic activity of tapentadol in both species remains limited, experimental studies indicate potential benefits in animals. This review summarizes and compares the pharmacology, pharmacokinetics, and therapeutic efficacy of tramadol and tapentadol in dogs and cats with different pain conditions. According to the available data, tramadol seems a more suitable therapeutic option for cats and should preferably be used as a component of multimodal analgesia in both species, particularly dogs. Tapentadol might possess a superior analgesic profile in small animals, but additional studies are required to comprehensively evaluate the activity of this opioid to manage pain in dogs and cats. [J Adv Vet Anim Res 2021; 8(3.000): 404-422]

OBJECTIVE To compare intraoperative and short-term postoperative variables pertaining to laparoscopic ovariectomy (LapOVE) and open ovariectomy (OVE) in rabbits (Oryctolagus cuniculus). ANIMALS Twelve 4− to 5-month-old female New Zealand White rabbits. PROCEDURES Rabbits were randomly assigned to undergo LapOVE (n = 6) or OVE (6), with a vessel-sealing device used to seal and transect the ovarian pedicles. Laparoscopic ovariectomy was performed with a 3-port approach. Variables were measured during surgery (surgery and anesthesia times and incision lengths) and for up to 7 days after surgery (food consumption, feces production, body weight, vital parameters, blood glucose and cortisol concentrations, abdominal palpation findings, facial grimace scale scores, and ethograms). RESULTS Mean surgery (43.2 vs 21.7 minutes) and anesthesia (76.2 vs 48.8 minutes) times were longer and mean incision length was shorter (24.0 vs 41.5 mm) for LapOVE versus OVE. No significant differences in postoperative variables were identified between groups. During LapOVE, small intestinal perforation occurred in 1 rabbit, which was then euthanized. Postoperative complications for the remaining rabbits included superficial incisional dehiscence (LapOVE, 1/5; OVE, 2/6), subcutaneous emphysema (LapOVE, 1/5; OVE, 0/6), and seroma formation (LapOVE, 1/5; OVE, 0/6). CONCLUSIONS AND CLINICAL RELEVANCE Surgery time for LapOVE was twice that of OVE, and LapOVE resulted in unique complications in rabbits. No evidence of a reduction in pain or faster return to baseline physiologic status was found for LapOVE. Further evaluation of LapOVE in rabbits is warranted, with modification to techniques used in this study or a larger sample size.