It is estimated that there are 1–1.5 million rabbits in the UK, making them the third most popular pet in the country (Protexin Vet, 2024). It has always been the author's professional opinion that arthritis in rabbits often goes undiagnosed and is much more prevalent than previously thought.
Aims
This study aimed to look at how owners perceive pain in their pet rabbits because if owners were not thinking their rabbit was in pain, they would not be taken to veterinary professionals to be assessed. It may often be the case that owners are thinking their pet is just ‘slowing down’ but, in actual fact, they may be suffering from a chronic health condition such as osteoarthritis (Rabbit Welfare Association and Fund, 2024a). Therefore, the owner's perception should not be underestimated.
Methods
Owner questionnaire
A sample of 100 rabbit owners responded to an online questionnaire which had 15 questions varying from age, breed and diet to symptoms of pain, concurrent health conditions and mobility of their pet.
Questions included asking the owners to confirm what they thought symptoms of pain in rabbits were. They were given a list of symptoms that could be considered to be signs of pain in rabbits, as well as some red herrings. They were also given an option for them to add their own symptoms. This list included inappetence, reduced grooming, limping, reduced movement, orbital tightening, cheek flattening, tooth grinding etc.
Results of owner questionnaire
Figure 1 shows the age of the rabbits. The results of the questionnaire were surprising. In total, 21% did not think tooth grinding was a sign of pain, 34% did not think reduced grooming was a sign of pain and 27% did not consider limping a sign of pain. The questionnaire continued to ask the owners about their own rabbits' health conditions and mobility status. Of the pooled rabbits, 60% were over the age of 7 years, and only 20% said they had never had any reported health conditions. At least 42% of those surveyed had been diagnosed with arthritis or spondylosis. This number may in fact be higher, as some did not specify what health conditions their rabbit suffered from. Despite these statistics, when asked to rate their rabbits mobility from very good to very poor, only 8.1% said poor or very poor and 33% rated their pet's mobility as very good (Figure 2). Owners were then asked to comment on their pets' mobility specifically and there were numerous responses commenting on lameness in their rabbits, stiffness and immobility, and even comments from owners whose rabbits are using wheelchairs.
Age of rabbits in questionnaire
Owners mobility scoring of their rabbits
Chronic pain assessment form
When considering where to go next in this project and reflecting on these results, a realisation occurred that living with a pet who has a chronic condition can be very challenging. Changes in prey species particularly can be very subtle and easily dismissed or unnoticed. The aim was to create a tool that can help ease the conversation between veterinary professionals and owners about their rabbit's ageing process. This would help to diagnose patients with conditions that cause chronic pain sooner and hopefully improve their welfare and quality of life. The chronic pain assessment form (Table 1) was developed and is a six-step process that can be easily completed as part of a routine health check such as booster vaccination or nurse consult. These six factors are age, breed, body condition scoring, coat condition scoring, mobility scoring and muscle condition scoring. The scoring system works as a traffic light system (Figure 3).
Rabbit chronic pain scale
Traffic light scoring system for chronic pain assessment
Pilot study
In order to appraise the form, the author and two colleagues went to a local rabbit rescue and independently assessed 26 rabbits using the chronic pain assessment form (Table 1). This was performed by using minimal handling and the owner of the rabbits was consulted to advise if there were any contraindications to handling the rabbits, ie transmissible diseases or temperament. Although there were a limited number of subjects, as all three assessors were assessing each participant without conferring, it would enable the scores to be compared and contrasted and hopefully see how objective the scoring system was. Table 2 is an example of the results from a 4-year-old, healthy, Mini Rex rabbit called Mags. As you can see here, the overall total score differed only very slightly between assessors (the overall average difference of the total scores was 0.5). What was also interesting from the assessments, is that the subjects who scored highest on this scale, were not necessarily those who the rescue were most concerned about or who were showing the most overt signs of illness. The highest scoring rabbit of the day was an 8-year-old, large breed rabbit called Bo (Table 3). He had very minimal health concerns having only been treated for a small facial abscess that had resolved. Unfortunately, a few weeks after the visit, Bo's mobility had deteriorated so much that the decision was made that it would be kindest to euthanize him.
Mags' chronic pain assessment
Category | Score 1 | Score 2 | Score 3 | Mean Score |
---|---|---|---|---|
Age | 1 | 1 | 1 | 1 |
Breed | 0 | 0 | 0 | 0 |
Body Condition | 2 | 2 | 2 | 2 |
Coat Condition | 1 | 1 | 1 | 1 |
Mobility Score | 0 | 0 | 0 | 0 |
Muscle Condition | 1 | 0 | 0 | 0.33 |
Total Score | 5 | 4 | 4 | 4.33 |
Bo's chronic pain assessment
Category | Score 1 | Score 2 | Score 3 | Mean Score |
---|---|---|---|---|
Age | 2 | 2 | 2 | 2 |
Breed | 3 | 3 | 3 | 3 |
Body Condition | 0 | 0 | 0 | 0 |
Coat Condition | 3 | 3 | 3 | 3 |
Mobility Score | 3 | 3 | 3 | 3 |
Muscle Condition | 2 | 3 | 2 | 2.33 |
Total Score | 13 | 14 | 13 | 13.33 |
Limitations
In order to see proper trends in data, far more data than what was acquired in this visit would need to be obtained. However, it did enable the appraisal of the form and begin to allow the extrapolation of theories of what would happen when larger numbers were possible. The next step is to get as much data as possible from veterinary professionals completing the chronic pain assessment forms. Once this has been done, my next stage would be to start to look at treatment options for these chronic pain patients and their efficacy.
Discussion
The chronic pain assessment form was based on the following factors.
Age
The older the rabbit the higher they would score on the assessment, as they would be more likely to have concurrent health conditions. A rabbit may be considered geriatric when they have reached 75–80% of their life expectancy and have begun to show age-related disease (Gardner, 2016).
Breed
Large breed rabbits are particularly prone to arthritis and spondylosis due to the excess pressure on their joints and they have a significantly shorter life expectancy than smaller breed rabbits (RWAF, 2024b). Anything upwards of 3.5 kg can be considered a large/giant breed rabbit (RWAF, 2024b). Large breed rabbits include Continental Giants, French Lops and New Zealand Whites and can weigh up to 10 kg (RWAF, 2024b).
Body condition scoring
Both ends of the scale score highly, as underweight or over-weight rabbits will both have higher risk factors associated with this. Obese rabbits will have higher risk for chronic pain as there is extra pressure on their joints (RWAF, 2024a). Being overweight also puts them at greater risk for heart disease, liver disease, neoplasias, pododermatitis, arthritis, bone fractures, urinary sediment and sludge, urinary infections, dental disease, dysbiosis, urine scalding and faecal accumulation – which may lead to myiasis, which is commonly known as flystrike (Royal Veterinary College, 2024). Meanwhile, underweight rabbits may be suffering from gastrointestinal parasites, dental disease, cardiovascular disease, neoplasias or infections (Pollock, 2010.) In order to body condition score the rabbits, the 1–5 body condition scale was used for ease of scoring adjusted from the rabbit size-o-meter (UK PetFood, 2022). Body condition scoring is a technique used to assess body condition in many species. There is no official scoring system that exists for rabbits, but evaluation of rabbit body condition can be adapted from methods used in cats, dogs and large animals. This requires an assessment by palpating fat and musculature over the ribs, bony prominences, and rump as well as evaluation of the dewlap (Pollock, 2022).
Coat condition scoring
Rabbits are extremely clean animals and will endeavour to keep themselves as clean as possible, even if their surroundings are not optimum. A rabbit with painful joints may also have difficulty reaching around to its backend, meaning they have more difficulty eating their soft, nutrient-rich night faeces or caecotrophs. This can lead to finding uneaten caecotrophs in their enclosures or cause them to have congealed faeces around their backend that puts them at greater risk to develop myiasis (McMenamin and Pollock, 2022). For rabbits going through seasonal moults, it may be helpful to suggest that owners send pictures a couple of weeks after examination to see if it has resolved and advise the owner on grooming techniques. Daily brushing and regular clipping of hair around the rear may also be necessary to ensure senior rabbits are kept clean and disease free (McMenamin and Pollock, 2022).
Mobility scoring
It may be helpful to do this at the end of the consultation by placing the carrier on the opposite side of the room. Most rabbits will want to run away and the veterinary professional can see at least three consecutive hops. If the rabbit is very nervous and freezes in the consultation room, they can be gently encouraged or ask the owner to send a video from home of them moving around. Normal gait for a rabbit would include the rabbit placing both front feet first individually then moving the back feet to join the front at the same time (Table 4). They sit at rest in a plantigrade stance but then shift to a digitigrade gait at movement. The only normal variation from this would be when they run or binky, anything else would be considered abnormal (Hall et al, 2022).
Princeton University - Gait Patterns
Muscle condition score
As this does not exist for rabbits yet, it has been adjusted from the cat and dog muscle condition scoring as the concept is much the same. Muscle condition is scored by visualisation and palpation of the scapulae, wings of ilea, spine and skull. On rabbits, the author finds this particularly easy to assess along the spine and hips. It is graded as severe loss, moderate loss, mild loss and normal. It is important to note that overweight animals may still have muscle wastage and this means that palpation in these animals is particularly important (WSAVA, 2013).
Conclusions
By doing a pilot study with blind scoring between the people taking observations, it allowed the assessment form to be appraised and showed its objectivity. In order to see true data trends, more subjects and data would be required. However, it is interesting to see trends and correlations arise among the subjects. It was also interesting to see that subjects who were not noted to be overtly unwell could still score very highly and even may have been compensating.