Anaesthesia in Reptiles
Performing anaesthesia in reptiles is an area I’ve had little experience as a small animal practitioner apart from once attempting to perform a chamber induction in a tortoise which seemed to take an alarmingly long time. Most owners phoning the practice regarding their exotic pet are actively encouraged by the well trained receptionists to seek advice at a more ‘specialist’ exotic practice. I continue to think this is the right approach to take but, that said , if I am presented with a sick snake, or tortoise , or iguana, I still have a responsibility to do the best by that animal, and watching last week’s veterinary webinar on reptile anaesthesia by Neil A. Forbes gave an excellent insight into this fascinating area of veterinary medicine.
One of the main take home messages I took from last week’s veterinary webinar was the surgical emergency that readily exists in the dog and cat does not exist in the reptile. Reptiles do everything slowly, including dying. Time should be taken to get these reptiles as medically healthy as possible prior to any anaesthetic and surgery to ensure the best outcome for these patients.
Planning well ahead of an anaesthetic and surgery is also crucial. A full pre-anaesthetic health assessment is always necessary and as reptiles can suffer from high endoparasitic burdens, a faecal sample can be very useful. However, unlike cats and dogs where a sample can often be obtained on the day of examination, an unwell tortoise could take three weeks to pass faecus, making early planning essential. Also analgesia in reptiles can take much longer to take effect compared to our mammalian patients and should be considered and planned for often well in advance of the surgery.
For surgical procedures Neil recommends opioids such as Morphine, but Morphine takes at least 6 hours to take effect and it is recommended to start analgesia in these patients the day prior to surgery. Neil went into detail about anaesthetic protocols for our most commonly encountered reptiles including chelonia (tortoises), snakes and lizards. Fluid therapy, dose rates, methods of induction and intubation were covered and unsurprisingly variations do exist between the taxa, and it is important to watch this webinar to get advice on what drugs to use and how to give them.
For example in tortoises, Neil advises not using propofol as it has been cited to cause tissue necrosis if given extravascularly. For short term anaesthesia, Neil uses alfaxalone and will intubate and maintain on iso if a longer anaesthetic time is required. Neil also gave an excellent step by step description of how to perform a subcarapacial induction in a tortoise.
This was an excellent veterinary webinar organised by ‘The Webinar Vet’, packed full of useful tips and information which would have taken an age to extract from the various texts available to us in practice. It is also reassuring to know that, according to Neil, most reptiles are in fact surprisingly forgiving when it comes to anaesthesia, being very tolerant to any lack of oxygen which may come about when things do occasionally go wrong. However by planning early enough and ensuring these reptiles get the best care, hopefully this will never happen.