Canine patient having a broken bone fixed with a metal plate and some screws. Orthopaedic surgery like this can be some of the most painful and an excellent pain control strategy is essential.
Of course your first concern when your pet is scheduled for surgery is ‘how painful are they likely to be?’ Firstly, rest assured that the myth that animals do not feel pain (and so we don’t need to do much about it) has been relegated to the depths! So how do we control pain in dogs and cats after surgery? The time when your pet is given an anaesthetic drug to make them unconscious is referred to as ‘induction of anaesthesia’. The provision of pain relief starts before induction. Drugs given just before the induction of anaesthesia are referred to as ‘premeds’; short for premedication or preanaesthetic medication.
The premed The premed usually involves administering a combination of a sedative and one or more drugs to prevent pain. The premed is designed to both calm your pet before the anaesthetic , and to start the process of pain control. It is widely recognised that if pain relief is started at this stage, pain is much easier to control both during an operation and afterwards.
Your pet may well be receiving pain killers already. Remember to check with your vet whether these drugs should be given on the morning of surgery.
What are the main pain killer drugs used in dogs and cats for pain control after surgery? The main pain killers used are the opioid analgesics. Analgesic is another word for pain killer – analgesia means without pain and of course our main aim in our patients is to prevent pain. Opioids are drugs that are similar to morphine. In the UK, the most common opioid used in dogs and cats is buprenorphine, followed by methadone. Opioids are administered by injection either into muscle, just under the skin (subcutaneously) or into a vein (intravenously) via a catheter. Opioids have been in use for many years and their effects are predictable and reliable. Your vet will decide which opioid to use in each case based on the anticipated level of pain.
Where possible we use local anaesthetic techniques. These provide the best type of pain relief because they block nerves which conduct the pain signal to the brain. We do not use these techniques in isolation – it is widely recognised that if we use several types of drugs we can achieve much better pain relief than using just one drug alone. We know how long our local anaesthetic technique will last and we make sure we use drugs such as opioids to supplement the pain killing effect. An epidural is one example of a local anaesthetic technique which you may be surprised to know is not just for humans. Epidurals can also be performed in dogs and cats (as well as many other species).
The third type of pain killer used routinely in the majority of anaesthetic protocols is the non steroidal anti inflammatory drug (NSAID). As well as being used to control surgical pain, we also use NSAIDs for provision of pain relief at home either following surgery or in long term conditions such as arthritis. The NSAIDs are excellent pain relieving drugs. Any type of surgery will cause some damage to the local tissues, which results in inflammation. During inflammation, chemicals are released by the body at the site of tissue damage or trauma. These chemicals act on nerve fibres to start the pain response. NSAIDs block the formation of some of these chemicals that promote pain and so by using NSAIDs we help to stop the generation of pain at the site of surgery as well as in the central nervous system (brain and spinal cord).
How long is pain relief provided after surgery? The short answer to this question is as long as the individual animal requires pain relief. Pain is a totally individual experience and if we perform the same surgical procedure in ten dogs or cats, then their individual experience of pain will differ. This reinforces the view that we should ‘pain score’ each patient and provide pain relief appropriate to them. We will talk more about how we recognise pain in pets in another article.
So if your pet is to undergo an operation, don’t be afraid to ask your vet what pain relief they are planning to provide. If you think that your pet is in pain when you get them home after a procedure, again do ask your vet about pain relief. The view that a bit of pain is a good thing because it restricts animals and allows them to heal is no longer accepted. Pain is detrimental to wound healing and may increase the chances of post-operative complications. You should generally expect your pet to be comfortable and eating normally after routine surgery.
About Matthew Gurney
Matt Gurney is a specialist veterinary anaesthetist based at Northwest Surgeons in Cheshire, UK. He is a Diplomate of The European College of Anaesthesia and Analgesia.
Northwest Surgeons
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