Routes and doses of lignocaine hydrochloride for analgesia of the velvet antler of stags

Aim. To evaluate the effectiveness of various routes of administration and doses of local anaesthetic to provide analgesia of the velvet antler of you ng stags. Methods. In study 1, in which an electrical stimulus was used, 64 1-year-ol d male red and red X wapiti deer with velvet antler 10-30 cm long, were ran domly allocated to one of ten treatments with four treatments/animal, and 2 3 or 24 antlers/treatment. Treatments delivered included three control grou ps, three local anaesthetic (2% lignocaine HCL) doses delivered by ring blo ck (5, 10 or 15 ml per pedicle), and a "high" or "low" regional block with or without an auriculopalpebral nerve block (5 ml per site). An electrical stimulus was applied before and 1, 2, 4 and 8 minutes after local anaesthet ic treatments and to controls, at an increasing voltage until a response wa s observed. The voltage and animal responses were recorded. In Study 2 the same seven local anaesthetic treatments (16-18 antlers/treat ment) were evaluated using 58 of the stags from Study 1 when antlers were r eady for removal, but a saw cut was used as the test stimulus. A test cut w as applied to the antler 1, 2 and 4 minutes after application of local anae sthetic. If no response was observed, the antler was removed at that time. Results. In Study 1, major dose and treatment effects were significantly di fferent (p < 0.05) with the outcome variable being whether or not the deer responded. No stags given the "high" dose ring block responded to electrica l stimulation 1 minute after treatment, one responded at 2 minutes, and non e responded at 4 or 8 minutes. At least one animal responded after all othe r treatments at all time intervals. More deer responded after the "low" reg ional block than the "high" regional block, and there was a lower response rare when the auriculopalpebral nerves were anaesthetised. In Study 2, no deer responded 2 minutes after the "medium" dose ring block treatment. Three of 18 stags receiving the "high" dose ring block still res ponded after 2 minutes, and one responded after 4 minutes. Responses occurr ed to all other treatments at each rime, with some deer requiring further a dministration of local anaesthetic before antler removal, even with the fou r minute waiting period. Conclusion. Ring blocks produced more consistent analgesia of the velvet an tler than regional nerve blocks. The "high" dose ring block produced analge sia faster and more effectively than lower doses, and the regional nerve bl ocks were more effective when the auriculopalpebral nerve was blocked.