Effects of age and reproductive status on postoperative pain after routine ovariohysterectomy in cats.

A prospective clinical trial to compare the effects of age and reproductive status on postoperative pain was conducted in 145 female cats undergoing ovariohysterectomy using injectable anaesthesia. The cats were grouped appropriately: 60 kittens <4 months old (K), 85 adults >4 months old (A) and, within the adult group, 57 normal adults (nA) and 28 adults who were either pregnant or in oestrus (rA). Pain was assessed using a simple descriptive scale (SDS; 0-3), a dynamic and interactive visual scale (DIVAS; 0-100 mm) and mechanical nociceptive thresholds (MNT; N, 2 mm diameter probe) pre-operatively and at 4 and 24 h postoperatively. Kittens had lower DIVAS areas under the time curve and SDS than adults (P <0.05), but similar MNT (K: 3.3 ± 2.6, A: 4.3 ± 2.5 N at 4 h, P >0.05). Data from nA and rA were not different (P >0.05). Kittens had similar wound tenderness, but less affective pain than adults, and reproductive status had no effect.