No one wants their dog to be in pain but unfortunately some dogs suffer in silence because their human parents do not read the signs correctly. Many dogs do not vocalise their discomfort and pain and bravely carry out their usual activities. This makes it incredibly hard for us doggy parents to know whether our beloved pooch is in pain or not. Let me help you develop a better grasp on the topic and give you some tools to make sure you clearly understand what your dog is telling you.
In order to be able to assess whether your dog is in pain it is important that you understand the difference between the two main types of pain: acute and chronic pain.
Acute vs chronic pain
Acute pain is often labeled as ‘good’ pain whilst chronic pain is considered ‘bad’ pain. Acute pain is ‘good’ because it is a normal response to an injury and prevents further harm as it encourages resting and healing. It is protective and usually short-lived. Chronic pain on the other hand is long-term and extends beyond the time expected for healing. It usually last longer than 3 months and some dogs live with chronic pain most of their life. It does not have a purpose and therefore can be considered ‘bad’ pain.
In fact, chronic pain can change the central nervous system (the brain) and make it more sensitive to pain. Chronic pain repeatedly stimulates the nerve fibres that are responsible for detecting, receiving and sending pain signals. This continuous stimulation (or constant messaging to/flooding of the brain) leads to your dog’s brain becoming ‘overwhelmed’ which causes changes in the emotional and cognitive areas of your brain. It can lead to the involvement of other processing areas such as signals for touch, pressure, temperature and vibration among others, being misinterpreted by the brain as pain.
If the pain is not managed appropriately, there is a risk of what is called the Wind-up Phenomenon which can lead to chronic neuropathic pain. When spinal neurons are subjected to repeated high intensity pain stimulus and this is not controlled with appropriate pain medication, they become gradually more ‘excitable’ even after the stimulus may be removed. Part of the wind-up process is also the involvement of processing areas that normally transmit signals such as pressure, temperature and vibration among others. The result is that nerve signaling for touch or temperature, for example, now signals for pain instead. In other words, many signals are being send to the brain, including touch, temperature, movement, position and vibration but they are all being interpreted by the brain as pain. If pain is left unmanaged for too long, there is a risk that patients may stop responding to common pain relieving medication.
“My dog is happy so it can’t be that bad”
This is were it gets tricky and I hear this, or a similar version of this statement, very often (i.e. “s/he still enjoys fetching the ball so it can’t be that bad” or “s/he still jumps onto the couch so it can’t be that bad”). In fact, you couldn’t be further from the truth. Simply because your dog is still performing certain activities doesn’t mean they are not in pain. You might ask: ‘why would they continue doing these activities if they hurt?’ and this is a very valid question to ask. Let me explain.
High value activities
We asked our dogs to perform certain activities their whole life like jumping in and out of the car, jumping on/off the couch or our bed, and fetching the ball in the park. These activities are not only habits but they are also high value activities. They are high value activities because for many dogs these activities are the highlights of their day. I am mainly talking about dogs who are confined to a house and backyard with limited room to roam and who are highly dependent on their owners to be physically and mentally stimulated (in comparison to farm dogs).
Jumping into the car very likely means a drive to the park or beach which is high on the entertainment list. Similarly, chasing the ball is clearly very exciting and who would turn down a bit of fun? Don’t we all love the release of dopamine and endorphin (the happy and feel-good hormones) in our bodies? And jumping onto the couch or bed means your dog can be close to their most favourite hooman. Clearly, these activities take priority and are often performed despite experiencing pain because the pleasure outweighs the pain. If your dog decides it hurts too much to perform these activities and therefore opts out of, for example to jump into the car or onto your bed, they have most likely been in pain for a while and their pain has reached a level that cannot be ignored anymore.
Endorphin – the body’s natural pain reliever
Another very important point to consider is that when your dog engages in high value, reward-producing activities, their body releases endorphins which are the body’s natural pain reliever. In other words, your dog feels less pain when engaging in these activities which correlates with the observation of most owners that their dog is ‘happy’ to perform certain activities and ‘does not seem to be in pain’.
Most research studies on endorphin release in humans is associated with physical exercise, however, there are studies particularly on the human-canine interaction which show that an increase in endorphin levels has been observed also during enjoyable interactions such as petting, looking at each other and talking to a dog. Interestingly, but not important for our argument here, is that endorphin levels increase in both dogs and humans.
Whilst endorphin release is a wonderful natural mechanism it unfortunately masks the reality of dog’s pain and makes it difficult for you to determine whether your dog experiences pain or not. Therefore, taking your dog’s willingness to perform certain activities as a benchmark for pain assessment might be somewhat misleading.
How to assess whether my dog is in pain?
Observation-based owner questionnaires
Several observation-based owner questionnaires and clinical measurement instruments (CMIs) have been developed and validated to assess and determine if, and to what extent, a dog is in pain.
I would like to add another worksheet developed by UK based veterinarian Hannah Capron from Canine Arthritis Management, a website every dog owner should consult if their dog has been diagnosed with arthritis.
Whilst each of these questionnaires take a slightly different approach and angle to determining and assessing pain in your dog, it is essential to keep in mind that your dog might not display symptoms all the time or to varying degrees (especially when they engage in high value activities and endorphins are being released).