Dog - Anaesthesia

We appreciate your concerns because your dog has to have a general anaesthetic. This handout of answers to some of the frequently asked questions we hope will help.

What is anaesthesia?

Loss of feeling or sensation. When we talk about anaesthesia today we usually imply general anaesthesia. This indicates a state of unconsciousness produced by drugs with the absence of any pain over the whole body together with variable amounts of muscle relaxation.

Are other types of anaesthesia used in animals and what are they?

Yes. Examples are local and spinal anaesthetics which are used in certain circumstances.

Do you think we are silly to be so worried?

No. You are merely concerned for your animal which is entirely normal. All anaesthetics carry some risk and each animal reacts slightly differently. Recently there have been huge improvements in safety and efficacy of anaesthetic drugs.

Each anaesthetic agent is tailored for the individual animal. Age, state of health, procedure etc. are all individually considered.

Why do we have to sign an anaesthetic consent form?

We ask you to sign an anaesthetic consent form, not because we fear the worst but to emphasise that the procedure does carry some risk and that you have been made aware of this. You can rest assured that your dog will be monitored carefully throughout the procedure and the recovery period.

What happens when I bring my dog to the practice?

At the time of admittance your dog will be carefully examined to check that no problem has arisen since we last examined him, which could affect tolerance of the anaesthetic. You will be asked when your dog last ate and drank and the type of food. The reason for this is that if we have to anaesthetise dogs with a full stomach, this sometimes causes problems with breathing when relaxed under the anaesthetic. Starving for 12 hours before an anaesthetic was at one time routine to prevent vomiting. Modern anaesthetic agents are less likely to, but still could, cause sickness but a full stomach can still cause problems.

What happens next?

As part of the pre-anaesthetic examination a premedicant will be administered. Today this is usually a sedative and an analgesic (pain killer). This combination ensures that your dog will not worry and will be relaxed and laid back although still awake and aware of his surroundings.

The analgesic is administered so that when he wakes up after the anaesthetic he will not be feeling any pain or discomfort from the surgery.

What sort of anaesthetic will you give my dog?

Today there are many different types of anaesthetic agents. After the premedicant has had time to work, general anaesthesia will be induced and this usually involves an intravenous injection which is administered slowly, usually into one of the veins of the front legs although occasionally a rear limb or the jugular vein in the neck will be used.

Once consciousness is lost the dog is laid on his side and an endotracheal tube is placed into his windpipe through the larynx. This is then connected via tubing to an anaesthetic machine and maintenance of anaesthesia begins. For this usually a gaseous anaesthetic is used together with oxygen. This ensures that while unconscious sufficient oxygen reaches the brain and tissues and at the same time allows controlled amounts of the selected anaesthetic agent to be administered.

These gaseous agents have a much shorter action than any of the injectable drugs and therefore anaesthesia can be controlled very much more precisely.

In some cases only oxygen is delivered from the anaesthetic apparatus and the level of anaesthesia is controlled by drugs delivered via an intravenous line. The choice depends very much on the condition and type of surgery etc. We are more than happy to discuss these individual aspects with you.

My dog is elderly. Will this be too much for him?

Until very recently most anaesthetic agents had profound effects on the heart and respiration (breathing). Today there are anaesthetics available which have gone a long way to remove these risks, therefore they are suitable for animals considered previously to be extremely poor risks, e.g. very old animals or those with heart or chest problems.

Will my dog take very long to come round from the anaesthetic?

The aim of balanced anaesthesia today is to try to ensure that the patient is beginning to regain consciousness as he leaves the operating theatre. However depending on the nature of the surgery, sedative agents may be administered to ensure that movement is kept to a minimum.

Could the shock kill him?

Treatment for shock today is an integral part of anaesthesia and it is for this reason that intravenous fluids are often administered before, during and/or after the operation. During this period the patient is monitored very carefully and respiration and heart rate in particular are checked.

If there is any aspect of the anaesthetic procedure outlined that concerns you and that you wish to discuss further, please feel free to contact us.