Objectives

This study aimed to evaluate the effects of combined grapiprant and tapentadol on intraoperative physiological parameters, the occurrence of adverse events and postoperative analgesic efficacy in cats undergoing elective ovariohysterectomy, using two multidimensional pain scales.

Methods

A total of 60 mixed-breed female cats were enrolled in a randomized, prospective, blinded study. The animals were evenly distributed into four groups (n = 15 per group). In total, 51 animals completed the study; the control group received placebo (CON; n = 11), while the grapiprant group (GRA; n = 13) received grapiprant (3.8 ± 0.5 mg/kg), the tapentadol group (TAP; n = 14) received tapentadol (5.3 ± 1.2 mg/kg) and the grapiprant-tapentadol group (GT; n = 13) received a combination of grapiprant (4.2 ± 0.5 mg/kg PO) and tapentadol (5 ± 0.6 mg/kg PO) 1 hour before initiation of the standardized anesthesia protocol and surgical procedure. Physiological parameters were monitored during surgery, and postoperative pain was assessed for 6 h after extubation using the Short Form of the UNESP-Botucatu Feline Pain Score (UFESP-SF) and the Feline Grimace Scale (FGS), administered by two blinded evaluators.

Results

No adverse effects or statistically significant differences in physiological parameters were observed between groups. The assessment of pain scores showed good reliability, with intraclass correlation coefficient values of 0.89 for the FGS and 0.91 for the UFESP-SF, supporting inter-rater agreement for both instruments. At 3 h postoperatively, FGS scores differed significantly between the CON and GT groups (P = 0.0363). Rescue analgesia requirements also varied among groups (P = 0.0110): the GT group required rescue at 3 h compared with 1 h in the CON group (P = 0.0007) and 2 h in the GRA group (P = 0.0058).

Conclusions and relevance

The results of this study showed that the analgesic effect of the grapiprant-tapentadol combination lasted up to 3 h in the postoperative period, which was longer than the 2 h of grapiprant and tapentadol alone, without compromising intraoperative physiological stability.

Plain language summary

This study evaluated the efficacy of two non-conventional drugs for postoperative pain management in female cats undergoing ovariohysterectomy. The study compared grapiprant, a non-steroidal anti-inflammatory drug used for inflammatory pain in dogs, with tapentadol, a synthetic opioid effective for both acute and chronic pain in humans. Grapiprant and tapentadol were administered orally, both individually and in combination, to cats undergoing ovariohysterectomy. Antinociceptive effects during surgery were assessed through physiological parameters. Two specific validated pain scales for cats, the Short Form of the UNESP-Botucatu Feline Pain Score and the Feline Grimace Scale, were used to assess analgesia during the first 6 h after surgery. Results demonstrated that the grapiprant–tapentadol combination showed superior efficacy in postoperative acute pain relief compared with either drug alone or placebo. Although this drug combination is novel in feline medicine, this study provides significant contributions to the literature regarding the use of grapiprant and tapentadol in postoperative pain management for female cats.

Search results

Efficacy of combined grapiprant and tapentadol for analgesia in cats undergoing elective ovariohysterectomy