Why is it important?
Anaesthesia is essentially rendering the dog unaware of the surgery we're performing, in a safe and reversible way. Without it, we wouldn't be able to perform any surgical procedures in a safe and ethical manner - from elective operations like spays and castrations up to major procedures like spinal and orthopaedic reconstruction surgery, we wouldn't be able to perform any of them. We appreciate that an anaesthetic on your dog is a stressful idea at the best of times, so in this factsheet we're going to go through the procedure for you and explain what will happen, and why we do it.
OK, let's look at the details
There are other types of anaesthetic (sedation, or local anaesthetic for example), but for most procedures, when we say "anaesthetic" we are talking about a general anaesthetic, where the dog is completely unconscious and unaware of what we're doing. This is in many ways the most useful type of anaesthesia, but there are definite risks associated with it - an anaesthetised dog is so deeply asleep that they cannot always maintain their own breathing rate, heart rate and blood pressure. We have skilled nurses who will be monitoring these parameters, and more, throughout the procedure under the supervision of a vet, so any deviation will be rapidly detected and dealt with. Because of the way the drugs work, any anaesthetic is a balancing act between the dog going too "deep" (and potentially coming to harm), or coming too "shallow" (and potentially running away!). We work to keep them at a level of sleep called "surgical anaesthesia" where they are comfortably asleep but still safe.
How safe are anaesthetics?
Anaesthetics in animals are very, very safe - severe complications in healthy dogs only occur in roughly 0.12% of anaesthetics (so less than 1 in 800), but if there are other disease processes, the dog is very sick, or is elderly, this risk is higher. As a result, we'll usually offer you a blood test, to rule out any underlying conditions such as liver disease, kidney disease, or anaemia, that could adversely affect them under anaesthesia. If we find a problem, it doesn't necessarily mean we can't do the anaesthetic - just that we might need to take some extra precautions.
So, what actually happens when a dog comes in for an anaesthetic?
First of all, they'll be seen either by one of the nurses or vets, who will give them a careful check over for any signs of something that might affect the anaesthetic - for example, a heart murmur or a fever.
What medicine do they get before surgery?
Assuming all is well, we'll then give them a premed - a combination sedative and painkiller to help them relax, and minimise any discomfort after their surgery (whatever it is). Using a premed also means that we can use a lower dose of anaesthetic, which reduces the risks. We'll move them into a quiet kennel to settle down and relax until we're ready.
How do you send them to sleep?
Once we're all set up for them, one of the nurses will bring them down to the prep area for induction, where we will send them off to sleep. This is usually done with an injection of drugs (usually propofol or alfaxalone), but sometimes we may use an anaesthetic gas by face mask.
What happens when the operation is over?
Once the procedure is over, we'll turn off the gas and allow them to start waking up, now that they're breathing just pure oxygen. Once they start to swallow, we'll take out the breathing tube, and then move them to the recovery area where the nurses can keep a close eye on them until they're awake and ready to go home. It's quite normal for a dog to be sleepy or a bit off colour after they get home - it may take them a while to clear all the anaesthetic from their system, especially if they're a bit older - but if you're at all concerned, feel free to call us at any time.
Anaesthesia seems really scary, and people get very worried about the risks. However, except in life-or-death emergencies, we will have carefully prepared, and we wouldn't recommend an anaesthetic unless the risk of not performing the operation was much higher than the risk of carrying it out. All our vets and nurses are fully trained in anaesthesia - because as we're all taught at vet school, there's no such thing as a safe anaesthetic, only a safe anaesthetist!