Anaesthesia in rabbits
A rabbit being sedated using a face mask
A rabbit being sedated using a face mask
Anaesthesia is a subject that often worries many owners, but at some point or another, most rabbits will undergo an anaesthetic during their life. It is important to therefore have an understanding of the subject.
What is anaesthesia?
Anaesthesia is defined as 'insensitivity to pain, especially as artificially induced by the administration of gases or the injection of drugs before surgical operations'.
A general anaesthetic is when the patient is placed into a state of unconsciousness. They are not able to feel pain, are paralysed and have no memory of what happens to them when they are under general anaesthetic. This is achieved by interrupting the passage of signals along the nerves. This means that any stimulation to the body doesn't get processed or recognised by the brain. However, an anaesthetic doesn't have to involve a general anaesthetic. Other types of anaesthetics exist, such as local anaesthetics which 'numb' a specific area, but the patient is still fully conscious.
Surgical procedures, such as neutering, dentals and anything that is likely to be painful to a rabbit requires anaesthesia. Sometimes it may be necessary to place the rabbit under anaesthetic for procedures when the rabbit must stay still, such as CT/MRI scanning, some x-rays, and blood samples, if the rabbit is very flighty.
These are injections, sprays or creams. They are normally used to block the sensation of pain along the nerve pathways, and can be used very successfully.
EMLA cream is often used on rabbits when placing intravenous catheters or taking blood samples and is a local anaesthetic in the form of a cream that numbs the surface of the skin, meaning the rabbit is less likely to move at the crucial moment when the needle punctures through the skin. This type of anaesthesia is not suitable for surgical procedures, since the rabbit is still able to move and feel sensation.
Epidurals create a nerve block, which means the patient remains conscious, but they cannot feel any sensation at the site of the epidural. This can therefore allow for surgery in a conscious rabbit.
A general anaesthetic places the rabbit into an unconscious state where they are unable to move or feel pain. This is the state that animals must be under when surgical procedures are performed on them.
There are many drugs and combinations of drugs that can be given to rabbits to achieve anaesthesia. The choice of anaesthetic is based on many deciding factors. The age of the rabbit, health status and the procedure to be undertaken, are all considered when deciding on which anaesthetic to use.
Normally a premedicant is given first; this helps to relax the muscles and has a calming effect on the rabbit, but doesn't always render them unconscious. Often, they may need other drugs or anaesthetic gas to achieve general anaesthesia. Rabbits are maintained under anaesthesia by an anaesthetic gas delivered via an endotracheal (ET) tube placed in their trachea (windpipe) which keeps them asleep as they breathe in the gas and oxygen. The ET tube also ensures that the rabbit has a secure airway throughout anaesthesia, should an emergency occur.
Is anaesthesia safe in rabbits?
Yes and no!
No anaesthetic is 100% safe, 100% of the time, and no two animals ever react the same to an anaesthetic, but rabbit anaesthesia has become far more reliable and safer over the last decade.
Ways that risks of anaesthesia are minimised include:
- Constant monitoring by trained staff when the rabbit is under anaesthetic.
- Get an accurate weight of the rabbit being anesthetised.
- Ensure the rabbit is eating and drinking properly prior to anaesthesia,
- Minimise stress, particularly placing them away from predators.
- Keep them warm before, during and after surgery.
- Give them medication for pain, and help keep the gastrointestinal tract moving.
- Place an endotracheal tube and intravenous catheter
- Use of familiar drugs that the vet is confident using.
Lowering the risk however doesn't remove it completely, and there is always the risk that the rabbit may suffer an adverse reaction to the drugs, die under anaesthetic, bleed excessively during or after surgery, or suffer complications.
Your vet must point out the risks involved in an anaesthetic, and for the specific procedure your rabbit is undergoing; your vet should also be confident with anaesthetising rabbits and the protocol that the practice has in place.
Should I starve my rabbit before an anaesthetic?
Rabbits must never be starved. Unlike dogs, cats and people, rabbits cannot vomit due to a very strong cardiac sphincter (the muscle at the top of the stomach). If dogs, cats or people are anaesthetised and haven't been starved, then vomiting is a serious concern. If this occurs then inhaling and choking is a potential danger, which can prove fatal. As rabbits cannot vomit, the risk does not affect them. Rabbits also need a constant throughput of food through their digestive system otherwise this can slow down which can prove fatal.
It is very important to never starve your rabbit prior to an anaesthetic and, if possible, take in some of their usual food when they go to the vets for an anaesthetic.
Will my rabbit need special care following an anaesthetic?
Anaesthesia will slow down the rabbit's gastrointestinal tract and reduce their body temperature. It is vitally important to get the rabbit eating, drinking and passing droppings and urine within 12 hours but preferable sooner. Rabbits in pain will be reluctant to eat, and therefore if anything painful has been done the rabbit must have pain relief and medication to try to ensure the digestive system doesn't slow down or stop completely.