Eight frequently asked questions about surgical general anaesthesia for dogs

If your dog has to have surgery because of an accident or illness, it is understandable that you’re going to be very anxious about their wellbeing, even if the operation in question is minor, routine, and your vet is very confident about your dog’s prognosis.

Your vet will take the time to explain everything to you, let you ask any questions you might have, and ensure that you’re confident in your decision to approve the surgery before you sign off on it (although naturally in an emergency situation, time might be a factor) and your vet is of course always the person you should speak to if you have any concerns before or afterwards.

However, understandably, most dog owners concentrate on the specifics of the surgery itself, what operation is being performed, and the logistics of what will happen regarding the issue necessitating the surgery – but anaesthesia is of course a vital element of any surgery, and one that can be complex, and not without risks.

Anaesthesia is the process of putting your dog to sleep for the duration of the operation, managing and monitoring them whilst the operation is ongoing, and waking them up again after the surgery itself. Anaesthesia is a specialist field of medicine, in which some doctors of human medicine – and some veterinary specialists – concentrate on, but which for most operations and in most clinics, will be managed by a general veterinary surgeon or member of their staff under their direction.

In this article, we will answer eight of the most frequently asked questions that vets are asked about general anaesthesia in dogs, to help you to develop a better understanding of the process. Read on to learn more.

What is the difference between a local anaesthetic, a general anaesthetic, and sedation?

A general anaesthetic is the type of anaesthetic used to put your dog into a chemically-induced sleep for a managed period of time, in order to enable a procedure to be performed.

A local anaesthetic is used to numb a certain, specific area of the body to enable an exploration, minor treatment or administration of a medication to be performed without your dog feeling it, but your dog remains conscious throughout this.

Sedation, on the other hand, makes your dog sleepy and less reactive in order to let certain procedures be undertaken – perhaps something minorly painful, or an X-ray, in which your dog needs to be kept still but won’t experience pain – but without putting them fully to sleep.

Why do we anaesthetise dogs for surgery?

Obviously nobody would want to be awake and conscious during a surgery, but there are actually several things that a general anaesthetic achieves.

First of all, general anaesthesia stops your dog feeling the pain of the procedure itself, and it also helps their muscles to relax so that their only movements are minor bodily functions like breathing, as well as removing the dog’s ability to move in order to keep them safe and enable the vet to do their work.

Who is responsible for my dog’s anaesthesia?

The vet performing the surgery on your dog and managing their case dictates and oversees the process of anaesthesia.

However, another person (which might be either another general practice veterinary surgeon, a veterinary nurse, or a specialist veterinary anaesthetist) will monitor and usually administer and adjust the anaesthetic drugs used to induce sleep, and the gases used to keep the dog unconscious, and everything else pertaining to the anaesthesia itself, so that the operating vet can concentrate on their work.

The anaesthetist remains with the dog continually with their whole attention on them, and the anaesthetist and the vet work very closely together, with the anaesthetist constantly monitoring a wide range of variables including the dog’s level of unconsciousness, their heart rate, breathing rate, temperature, blood pressure and much more, and feeding this information back to the operating vet so that they can make decisions about the dog’s care.

Do dogs have the same anaesthesia as humans?

There is a lot of crossover between human and veterinary anaesthesia, and a lot of the same drugs and gases used in veterinary medicine are also used for humans! However, the dosage of every medication and which ones are used for any specific dog are all calculated and determined individually, and not all drugs used in veterinary medicine are used for humans and vice versa.

Why do I need to withhold food prior to my dog’s anaesthesia?

Dogs need to have an empty stomach for their operation as some of the anaesthetic drugs used can cause nausea and vomiting. This is a choking risk for the dog, and of course, would cause huge and potentially unresolvable problems in and after the surgery.

Your vet will tell you what time to withhold food from (usually eight hours prior to the earliest time they expect to operate) and you must observe this. If you miscalculate or your dog manages to eat something, you must tell your vet before the surgery, and they might delay the surgery as a result.

How are anaesthetised dogs woken up, and how long does this take?

The anaesthetic medications used to put your dog into their sleep are reversed with other chemicals, to bring your dog back to consciousness as soon as possible.

Your dog would eventually wake up naturally after the anaesthetic drugs were stopped if this was not done but the longer a dog is under anaesthetic for, the greater the potential risks, and dogs under anaesthetic also need continual one to one monitoring and supervision.

It can take anything from around 15 minutes to two hours for a dog to return to wakefulness enough not to need continual supervision, and when they start to come round properly, they will generally be encouraged to eat as soon as possible.

As soon as your dog starts to exhibit their gag reflex, the ET tube (breathing tube) is removed from their throat, and dogs are generally put in a secure kennel from this point until they are fully awake and behaving largely normally, as coming round from an operation is highly disorienting, particularly when in a strange place with strange people around, and some dogs will display defensive aggression as a result of this.

Is anaesthesia safe for dogs?

Anaesthesia is generally safe for most dogs, but it does come accompanied with a number of variables and potential risks. Some dogs don’t react well to anaesthetics, some don’t tolerate certain commonly used drugs, older dogs tend to be more at risk, and the longer a dog is anaesthetised for, the higher the risks in general.

This means that your vet will consider the risks and benefits for each dog very carefully, taking into account every element of your dog’s case and their health and even their breed, to determine the potential hazards and the best way to proceed.

If they have specific concerns but still feel that anaesthesia is needed, they will discuss this with you at length, and ultimately help you to make the right decision.