THERE HAS BEEN INCREASING INTEREST OVER RECENT YEARS IN THE DETECTION AND MANAGEMENT OF ACUTE PAIN in companion animals and in understanding the importance of pain management in association with surgical and medical procedures.
Recognition of the pathological nature of chronic pain has also improved but the detection of chronic pain is a challenge for the veterinary profession and behavioural signs can play an important part in dealing with these cases.
Perhaps the most obvious behavioural manifestations of pain are those which are directly associated with handling or interacting with the animal and cases of overt aggressive behaviour in such contexts might readily lead to investigation of a potential medical cause. However, the role of associative learning and of the emotional dimension to pain should not be underestimated and the potential for more diverse behavioural changes in animals with chronic pain should also be considered.
It needs to be remembered that aggression is not the only potential behavioural manifestation and in cases where individuals develop behavioural coping strategies in order to deal with the pain it is possible for these responses to become ritualised and even compulsive in nature. Accurate history taking and good clinical examination is therefore essential.
Observation
One of the biggest constraints for the general practitioner in the detection of pain is the lack of time with the patient and the inability to observe the animal in a variety of situations where pain is most likely to have a significant effect on their behaviour.
In behavioural consultations of three hours’ duration which are commonly held in the owner’s home there is a distinct advantage. When the behavioural history and more extensive observation are indicative of a potential pain component it makes sense for this body of information to take precedence over the results of a clinical examination in a veterinary consulting room, and even over the results of radiographic information, when making a decision about therapeutic intervention.
In the general practice context, the use of modern technology can really assist in the detection of pain and asking clients to provide video footage of patients when they are on walks, getting in and out of cars and going up and down stairs can be extremely beneficial.
Due to the negative emotional effect of a visit to the veterinary practice, and the likelihood of patients being inhibited when they are there, the value of repeated clinical examination in the consulting room is limited.
With most owners now having access to a smart phone it has never been easier for general practices to ask for the submission of short video clips of their patients in a variety of contexts and collecting a series of video clips over time can also assist in the monitoring of response to pain management. Asking the owner to keep a diary of behavioural indicators can also help in this process.
Emotional significance
There are a wide range of possible behavioural manifestations of pain. Some of them are direct consequences, such as aggressive responses to being handled, refusal to exercise, inability to access parts of the territory, vocalisation and night-time waking, but others are subtle indirect consequences that many owners and veterinary team members do not readily detect.
Pain is a complex issue with sensory and motor components that are well understood but also cognitive and emotional components that have, until recently, been largely overlooked in the veterinary context. When animals are suffering from chronic pain, the effect on their resting level of emotional arousal can be significant and as a result of this utilisation of emotional capacity the individual may be less able to cope with other emotional situations.
As a consequence, the display of behavioural responses, including repulsion, avoidance, appeasement and inhibition, is more likely and the signs that the owner recognises are therefore behavioural in nature.
The list of possible behavioural manifestations with a pain component to their aetiology is extensive but some common examples would include exaggerated canine fear responses to noises, strangers or other dogs and alterations in feline behaviour such as unacceptable indoor toileting or breakdowns in inter-cat relationships within multi-cat households.
Consideration of the potential for pain is an important part of any behavioural investigation and should always be considered when clients report behavioural problems with their pets.
Indicator of pain in dogs
The recognition of the importance of pain for veterinary patients is relatively recent but, to put it in context, the use of analgesia in paediatric human surgery is also a relatively new development.
Sadly, there is still some resistance to accepting the relevance of pain in the onset and progression of behavioural signs in companion animals but research into the importance of analgesia in both a surgical and medical context is beginning to help to turn the tide.
Work at Glasgow University to develop a pain assessment system for dogs has highlighted the importance of behavioural signs and the development of the Glasgow pain score has established behavioural change as a primary indicator of pain in dogs.
Practical considerations for the painful dog
Investigate and treat underlying source of pain.
- Use analgesic medication as appropriate and trial periods of medication where there is doubt about the relevance of pain – consider the use of polypharmacy and do not rule out pain on the basis of the response to one form of analgesic medication.
- Provide indirect means of moving the dog, including house lines and food trails and avoid any form of dragging or pushing. Do not pull on the collar to move the dog.
- Avoid handling where possible and provide access to vehicles through the use of ramps.
- Encourage exercise through short walks and make the experience inherently rewarding.
- Tailor exercise and interaction to the individual situation of the case.
- Embark on specific counter-conditioning programmes to establish positive associations with dilute forms of handling.
- If appropriate, consider referral to colleagues working in the disciplines of chronic pain management and rehabilitation medicine.
Detecting pain in cats
The use of behavioural indicators to develop a pain score for cats has not proved to be so straightforward but work by Sheilah Robertson on the use of feline facial expressions to assess acute pain, and the development of the feline pain score at Glasgow University, have been extremely important advancements in the context of feline welfare.
Cats are particularly stoical creatures. Showing signs of pain could make a solitary survivor vulnerable and therefore passive signs of pain are far more likely than the more obvious signs that we associate with canine patients.
Owners may be unaware of the cat’s change in mobility and it is vital during history taking to ask the correct questions in order to identify subtle signs that the cat is having difficulty in moving around, grooming itself or interacting on a social level either with cats or people.
Practical considerations for the painful cat
- Investigate and treat underlying source of pain.
- Use analgesic medication as appropriate and trial periods of medication where there is doubt about the relevance of pain – consider the use of polypharmacy and do not rule out pain on the basis of the response to one form of analgesic medication.
- Investigate the role of environmental management.
– provide more readily accessible elevated resting and hiding places;
– provide more readily accessible latrines and where necessary modify the tray to encourage its use;
– increase the number of trays available and place close to resting places for speed of access.
- Be aware of potential pain when handling elderly cats and allow them to take the initiative.
- Encourage exercise through very short but frequent episodes of toy directed play.
- Tailor the games to the physical fitness of the individual.
- If appropriate consider referral to colleagues working in the disciplines of chronic pain management and rehabilitation medicine.
Conclusions
The importance of the identification and management of both acute and chronic pain in a veterinary context has become increasingly recognised over recent years.
For those working in general practice, consideration of behavioural indicators can be extremely beneficial in increasing the detection rate and the bilateral relationship between pain and behaviour increases the importance of incorporating behavioural investigation into the clinical approach to medical and surgical cases.
Further reading
- 2014 WSAVA Global Community Guidelines for recognition, assessment and treatment of pain. Karol Mathews (Canada), Peter W. Kronen (Switzerland), Duncan Lascelles (USA), Andrea Nolan (UK), Sheilah Robertson (USA), Paulo V. M. Steagall (Brazil/Canada), Bonnie Wright (USA), Kazuto Yamashita (Japan).
- 2015 AAHA/AAFP Pain Management Guidelines for Dogs and Cats. Mark Epstein (co-chairperson), Ilona Rodan (co chairperson), Gregg Griffenhagen, Jamie Kadrlik, Michael Petty, Sheilah Robertson, Wendy Simpson.
