We’re all used to giving dogs and cats pain relief pre and post-surgery, as well as for chronic conditions such as arthritis, but how often do we think about our rabbit patients.
Posted: 29 May 2019
The answer is probably more than we used to, but we could still be doing more, particularly as there have been numerous studies over the years to show that analgesia in rabbits is often inadequate.
Part of the problem arises because the assessment of pain in rabbits can be difficult and challenging. As a prey species they are masters at hiding the signs of pain, so we have to watch carefully and know what we are looking for.
Pain has been defined as ‘an unpleasant sensory and emotional experience associated with actual or potential tissue damage’.
There are all sorts of painful procedures and conditions in rabbits which would benefit from intervention with analgesia. Some typical examples we might see include;
As we’ve already mentioned, recognising pain in prey species can be difficult, and in rabbits it can be affected by a number of variables. For example, you need to take into account;
Knowing what is normal will help, since slight variations from the norm may be all that you can find to know the animal is experiencing pain. Some examples include;
We’ve been using qualitative and quantitative measurements of pain for years in other species, and the ‘Grimace scale’ is just one example of a pain assessment guide. The idea is to look at the animal carefully and take note of small changes in facial expression, all of which help you to quantify pain. The specific facial features change according to the level of the pain. Some facial indicators include;
We are increasingly aware of the need to give analgesics prior to and after surgery. By doing this you’ll reduce the dose and risks from anaesthesia, as well as minimise any complications during the recovery period as a result of pain and stress (e.g. gut stasis). It can’t be stressed enough how important it is to give effective pain relief to rabbits when considering surgery.
Whilst underused, there are still opportunities and situations when drug free pain relief can be used. This might involve the use of;
The three main groups of analgesics available to us in the UK are opiates, nonsteroidal anti-inflammatory drugs (NSAID’s) and local anaesthetics. These can be used alone or in combination.
Now widely used, these produce both central and peripheral pain relief. They are generally safe, versatile and often reversible. The most frequently used opiates are the synthetic partial agonists, buprenorphine and butorphanol.
Butorphanol is around 5 times as potent as morphine, whilst buprenorphine is even more effective, being around 30 times stronger. They can both be dosed to effect and importantly, don’t cause significant CNS depression.
Side effects are generally only seen when an animal receives an overdose, which could result in;
This group of drugs is widely used in small animal and exotic practice. They not only have analgesic properties, but also anti-inflammatory and antipyretic effects. You have to be cautious when using them though as they are contraindicated with;
The most frequently used NSAID’s in rabbits are meloxicam and carprofen.
These work by blocking the transmission of a painful stimulation to the central nervous system. A common local anaesthetic used in rabbits is EMLA cream (a mix of prilocaine and lidocaine). EMLA cream is frequently used for placement of intravenous catheters.
Other local anaesthetics include lidocaine and bupivacaine, which are used for;