Anaesthetic considerations for aggressive dogs

Authors: Beths T
Publication: Australian Veterinary Practitioner, Volume 55, Issue 1, pp 24-28, Mar 2025
Publisher: Australian Veterinary Association

Animal type: Dog
Article class: Clinical Article

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Abstract:

General anaesthesia (GA) is commonly used in veterinary practice to allow for invasive procedures such as surgeries and less invasive procedures such as blood sampling, imaging (x-rays, CT, MRI, ultrasound), dental work, etc. Owners and veterinarians often see anaesthesia as a single event where an animal is "put under" to allow a procedure to happen. Anaesthesia should be regarded as a continuum of care, starting at home, where the animal will be fasted and may receive analgesic and even anxiolytic drugs. The procedure carries on in the hospital through the pre-anaesthesia, induction, maintenance, and recovery phases. The continuum of care ends with the post-anaesthesia phase, which includes time at the hospital and the return home. The team of veterinarians and nurses involved with the anaesthesia must minimise the detrimental effects associated with perioperative pain and stress for each animal based on history, comorbidities, physical examination and procedure-associated risks. One of the challenges the anaesthesia team often has to overcome is to deal with aggressive dogs.

Unfortunately, aggressive dogs seem to become more common in general practice and referral centres. The signs of aggressivity have been well described elsewhere (AAHA) and may include avoidance behaviour (licking, panting, avoiding eye contact), raised hackles (indicating heightened arousal or aggression), direct staring, growling or snarling, bared teeth, raised lips, wrinkled muzzle or forehead, lunging or charging forward, stiff tail or wagging held high, freezing or stillness. While fear and anxiety might be the most common causes of aggression in dogs, pain and discomfort are also high on the list; and those might even be feeding each other. Fear and anxiety may increase pain perception, and pain or its anticipation can exacerbate anxiety. For a list of different causes of aggression in dogs (and cats), the author refers readers to a 2021 review paper from Riemer et al.

Aggressive dogs pose a challenge to the anaesthesia team. The animals often cannot have a thorough physical examination (PE), and their history might be incomplete due to the lack of PE during previous encounters with veterinarians. In addition, stress associated with the aggressivity results in the activation of the hypothalamic-pituitary-adrenal axis and the sympathetic system associated with increased plasma ACTH and cortisol, increased sensitivity to pain, longer post-surgical recovery, increased risks of infection and delayed healing.

Keywords: Aggressive, fear, sedation, general anaesthesia, dogs

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