Effects of surgery, anesthesia and pain on reproduction and behaviour of captive and free-ranging ducks
Machin, Karen L.
Intra-abdominal radio transmitters are used to provide valuable information on reproduction, movement patterns, habitat use, and survival in a variety of wildlife species, including waterfowl. Pain and stress associated during capture, handling, anesthesia, and with instrumentation during surgery may have sublethal consequences, which may interfere with normal behaviour. As pain is produced by any procedure or injury that causes tissue damage, it is likely that waterfowl implanted with radio transmitters would experience pain. Also, placement of transmitters during incubation necessitates an incision into the brood patch which may have significant implications, such as altered incubation patterns resulting in delayed hatch. Therefore this study attempted to quantify the effects of pain and its treatment on captive and free-ranging waterfowl. Plasma thromboxane B2 levels indicated that two nonsteroidal anti-inflammatory drugs (flunixin and ketoprofen) may exert pharmacological effects for at least 12 hours in mallard ducks. However, use of flunixin in waterfowl cannot be recommended because of extensive muscular necrosis. Treatment isoflurane-anesthetized mallards with ketoprofen demonstrated a significant analgesic through reduction heart and respiratory rate changes in response to painful stimuli. In free-ranging mallards, longer surgeries were correlated with increased time to first nesting attempt after intra-abdominal transmitter placement. Females that received ketoprofen took 3.5 days less to the first nesting attempt than females that received saline, indicating that analgesia was beneficial. There was no evidence to suggest that ketoprofen was harmful. Bupivacaine (local anesthetic) may be shorter acting in ducks than in mammals. Sequestration and redistribution of bupivacaine may result in delayed toxicity but mechanisms are unknown. In ruddy ducks, bupivacaine did not appear to achieve long-term analgesia or prevention of post-operative pain-related behaviours. In nesting female mallards, surgery altered incubation patterns in the 24 hour post-operative period, regardless of analgesic (ketoprofen or bupivacaine). Incubation period duration was extended in bupivacaine-treated females compared to ketoprofen-treated females, indicating that analgesia may interfere with brood patch sensation. Increases in corticosterone and progesterone were detected following surgery which may indicate stress and/or pain. The benefits of administering analgesia cannot be overlooked in minimizing effects of placement of radio transmitters on free-ranging waterfowl.