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- Introduction to Anesthesia in Fallow Deer: Anesthesia is crucial for safe wildlife management, allowing operators to work securely and minimizing animal suffering. This document details techniques and drugs for fallow deer anesthesia.
- Administration Methods:
- Dart Guns (Teleanesthesia):
- Explosive-charge guns: Outdated, dangerous, heavy darts, unreliable injection, requires frequent cleaning.
- CO2/air-compressed guns: More modern, manageable, accurate up to 60m, but expensive darts/needles, requires gun license.
- Blowpipes: Inexpensive, portable, no license needed, but limited range (5-6m) and unsuitable for animals with thick skin.
- Self-injecting pole (spring or CO2): Versatile, affordable (€250), extendable to 2m, injects up to 15cc, essential for mechanical captures.
- Manual Injection: Last resort for mechanical captures, dangerous for operators, stressful for animals.
- Dart Guns (Teleanesthesia):
- Anesthesia-related Problems:
- Overdose: Common due to difficulty in pre-weighing wild animals. Antagonists exist for some drugs, otherwise symptomatic therapy.
- Collapse-Shock: Occurs in physically compromised animals, during long chases or transport. Prevention is key.
- Heatstroke/Hypothermia: Induced by extreme temperatures or exertion. Symptomatic treatment; avoid anesthesia in adverse climates.
- Ruminal Meteorism (Bloat): Anesthesia reduces physiological rhythms, including prestomach motility. Fermentation continues, leading to gas buildup. Positioning animal on right side with elevated head, or using a ruminal tube.
- Available Anesthetic Drugs:
- Cycloexylamines (Ketamine, Tiletamine):
- Rapid immobilization, analgesia, dissociative cataleptic anesthesia.
- Can cause muscle spasms, rigidity, and tremors during recovery.
- Can increase salivation (controlled with atropine sulfate).
- Combination with benzodiazepines reduces convulsions; with alpha-2 agonists improves analgesia/myorelaxation. No known antidote.
- Benzodiazepines (Diazepam, Zolazepam):
- Sedative, myorelaxant, low toxicity. Antagonists (flumazenil) exist.
- Excellent in combination with cycloexylamines. Diazepam often used with ketamine, zolazepam with tiletamine.
- Alpha-2 Agonists (Xylazine, Medetomidine):
- Xylazine: Rapid induction (minutes), but anesthesia depth can be low, leading to partial arousal. Potentiates cycloexylamines. Contraindicated in pregnant animals (abortion risk). Can cause respiratory depression and ruminal meteorism. Antagonized by yohimbine/atipamezole.
- Medetomidine: 30-40x more potent than xylazine. High risk of cardiorespiratory depression, bradycardia, abortion. Not recommended based on INFS experience.
- Cycloexylamines (Ketamine, Tiletamine):
- Anesthetic Mixtures:
- Hellabrunner Mixture (HBM): Ketamine + Xylazine. Potent, allows low dosages, reducing risks.
- Contains 125mg xylazine, 100mg ketamine per ml.
- Dose for fallow deer: 0.019 ml/kg BW (2.34mg xylazine, 1.9mg ketamine).
- Induction ~11 min, duration >40 min. Recovery with tremors and unsteadiness. Xylazine can be antagonized, but ketamine effects remain.
- Zolazepam, Tiletamine, Xylazine (MWB): Advantages: no ketamine (regulated), presence of benzodiazepine prevents catatonic phenomena after xylazine antagonism.
- Contains 50mg xylazine, 25mg zolazepam, 25mg tiletamine per ml.
- Dose for fallow deer: 0.03 ml/kg BW (1.5mg xylazine, 0.75mg zolazepam, 0.75mg tiletamine).
- Rapid induction (~5 min). If xylazine not antagonized, anesthesia >40 min.
- Atipamezole (1mg/10mg xylazine) allows rapid recovery (3-12 min), animals stand naturally, run, and rejoin groups without behavioral issues. Useful for stressed animals in mechanical captures.
- Hellabrunner Mixture (HBM): Ketamine + Xylazine. Potent, allows low dosages, reducing risks.
- Dosage Tables (MWB for Fallow Deer): Detailed tables for various animal weights (50-135 kg) showing corresponding MWB (ml) and Atipamezole (ml) dosages, along with cost estimations.
- Conclusions: Modern pharmacology offers effective and safe anesthesia for fallow deer, but adherence to regulations, skilled personnel, ethical considerations, proper planning, authorized enclosures, and animal welfare are paramount.