This study aimed to evaluate the preemptive analgesic effect of amantadine on postoperative pain control in female dogs that underwent ovariohysterectomy. Twenty female dog were randomly assigned to two groups of ten. The control group (CONTROL) received oral placebo capsules, while the amantadine (AMANT) group received 5 mg/kg of oral amantadine one hour before sedation. All the animals were premedicated with 3 mg/kg (IM) meperidine, induced with propofol and maintained with isofluorane. The transanesthetic physiological parameters were recorded, and postoperative pain was evaluated every hour after extubation for six hours with the Dynamic Interactive Visual Analog Scale (DIVAS) and mechanical nociceptive threshold (MNT) and when the necessary analgesic rescue was administered (morphine, 0.2 mg/kg (IM)). During the surgical procedure, there was no significant difference in the variables measured between the two groups. Regarding postoperative pain assessment, there was a significant difference in the DIVAS score (p = 0.004) between the groups, in which AMANT required fewer rescues than did CONTROL (p = 0.03). The MNT was significantly higher ​​in AMANT than in CONTROL (p = 0.03). The results suggested that the preoperative administration of amantadine decreased analgesic requirement in female dogs that underwent elective ovariohysterectomy.

Maropitant is a neurokinin-1 (NK1) receptor antagonist that can be used for pain management. The objective of this study was to evaluate the effect of continuous infusion of two doses of maropitant on cardiorespiratory parameters and its postoperative analgesic effect in cats undergoing ovariohysterectomy. Thirty cats were randomly assigned to one of three groups (10 cats each group): the control group (CG) received a continuous infusion of 10 ml/kg/h Ringer’s lactate; GM30 and GM100 first received an intravenous (IV) bolus of 1 mg/kg maropitant; GM30 then received continuous infusion of 30 μg/kg/h maropitant; and GM100 then received continuous infusion of 100 μg/kg/h maropitant. The maropitant was diluted into Ringer’s lactate and the GM30 and GM100 also received fluids intraoperatively. In all groups, premedication included intramuscular injections of morphine and acepromazine, followed by induction with propofol and maintenance with isoflurane. Temperature, heart rate (HR), Doppler blood pressure (DBP), respiratory rate, oxygen saturation, and measuring the end-tidal carbon dioxide and isoflurane were monitored. Postoperative pain was evaluated using a visual analog scale and the UNESP-Botucatu multidimensional composite pain scale in cats; morphine was used for analgesic rescue. During the surgical procedure, cats in GM100 demonstrated lower HR and DBP than those in CG. With regard to the evaluation of postoperative pain, GM100 required the least frequent morphine rescue and less rescue analgesia compared with CG. In conclusion, cats in GM100 maintained lower DBP and HR and required lower analgesic rescue during the postoperative period. The results suggested that animals receiving maropitant bolus (1 mg/kg) plus (100 μg/kg/h) experienced greater postoperative comfort, reflected by the lesser need for analgesic rescue. The use of maropitant in surgical procedures in cats contributes to postoperative comfort.

Failures in hypothalamic kisspeptin/Kiss1r signaling are associated with infertility, and in vitro studies have shown that kisspeptin can modulate angiogenesis and immune activity. Because there is no in vivo research on the functional relationship between these factors in the reproductive system, especially in domestic cats, we evaluated the expression profile of kisspeptin/Kiss1r and angiogenic and immunological mediators in the genital tract of cyclic cats and of those with pyometra. The uterus of cats in diestrus exhibited greater gene and protein expression of Kiss1, as well as Vegf, Pigf, Mif, and Il6. In contrast, Kiss1r presented greater expression in proestrus/estrus, similarly to that observed for the immunostaining of INFγ, MIF, TNFα, and IL10. These factors were positively correlated with Kiss1 and/or Kiss1r, and a positive correlation between Kiss1 and Kiss1r was also observed in the uterus of cats during the estrous cycle. Cats with pyometra showed greater immunostaining of Kiss1 and Kiss1r on the endometrial surface and reduced immunostaining of Kiss1 in deep glands, whereas there was a significant reduction in Vegf, Pigf, Mif, and Il6 mRNA, and an increase in Tnf mRNA. The findings reveal that there is a gene correlation between kisspeptin/Kiss1r and angiogenic and immune mediators in the uterus of the domestic cat, which are modulated by the estrous cycle, and that pyometra affects the expression of these mediators. This study suggests, for the first time, a functional relationship between the Kiss/Kiss1r system and angiogenic and immune mediators in the female genital tract.

Maropitant, an antagonist of neurokinin-1 (NK-1) receptors, blocks the pharmacological action of substance P on the central and peripheral nervous systems. The objective of this study was to compare the antinociceptive and cardiorespiratory effects of the continuous intraoperative infusion of maropitant with ketamine and lidocaine in female dogs undergoing unilateral radical mastectomy. Twenty-four female dogs were used and were divided randomly into two groups (n = 12). The GLK group received ketamine bolus (1.0 mg/kg), lidocaine bolus (1.5 mg/kg), and continuous infusion of ketamine and lidocaine (10 mcg/kg/min and 50 mcg/kg/min), respectively; the GLKM group received the same anesthetic protocol combined with maropitant bolus (1.5 mg/kg/IV) and continuous infusion of maropitant (100 mcg/kg/h). Continuous infusion was initiated at the start of surgery and was maintained until 1 hour postoperatively. Pain was evaluated in the postoperative period using four scales and a digital analgesimeter. Data were analysed using analysis of variance, Student's t-test, Mann–Whitney test, and Friedman’s test ( P  < 0.05). Kaplan–Meier curves were compared using the log-rank test. The results indicated lower pain scores, better survival curves with a lower number of patients requiring rescue analgesia, and lower peripheral sensitization, in the GLKM group than in the GLK group. It was concluded that the coadministration of maropitant with ketamine and lidocaine had an adjuvant effect with minimal cardiorespiratory effects and effective analgesia, improving pain management and patient comfort.

Background Multimodal analgesia consists of the combination of analgesic drugs at low doses to act in different places along the path of pain. Studies with continuous infusion of analgesic drugs in cats are not common. This study aimed to evaluate the analgesic effect of maropitant, lidocaine and ketamine alone or in combination (intravenous bolus + subsequent continuous intravenous infusion) in the management of acute postoperative pain in cats undergoing ovariohysterectomy. Seventy healthy cats undergoing an ovariohysterectomy received a standard anesthetic protocol consisting of acepromazine and morphine, propofol (anesthesia induction), and isoflurane (anesthesia maintenance). The animals were stratified into seven groups (n = 10 in each group): control (CG), maropitant (MG), lidocaine (LG), ketamine (KG), maropitant + lidocaine (LMG), maropitant + ketamine (KMG), and maropitant + lidocaine + ketamine (LKMG). All drugs were injected first as an intravenous bolus and then by continuous intravenous infusion. During surgery, esophageal temperature, respiratory rate, heart rate, oxygen saturation, expired isoflurane concentration, and partial pressure of carbon dioxide at the end of expiration were evaluated at 7 time points. Postoperative pain was evaluated for 6 h after extubation using the visual analogue scale and the UNESP-Botucatu multidimensional composite pain scale for assessing postoperative pain in cats. Results Adverse effects related to maropitant, lidocaine and ketamine infusion were not observed. Pain scores were lower in the MG, KG and LG groups when compared to the CG group using both scales. Although pain scores were also lower in all combination groups than CG, more animals in these groups required rescue analgesia compared to MG. This indicates that the postoperative analgesic effect of all drugs, either alone or in combination, confers analgesia, although the combinations did not promote greater analgesia. Conclusions Continuous intravenous infusion of maropitant, lidocaine, and ketamine alone induces postoperative analgesic effect in cats undergoing ovariohysterectomy, but combinations of these drugs did not increase the analgesic effect. No adverse effect was observed with any drug or their combination.