Lop-eared rabbits at risk of hidden ear disease, study shows
Lop-eared rabbits were more likely to show ear abnormalities, including ear canal narrowing.
A study from the Royal Veterinary College (RVC) has confirmed that lop-eared rabbits are at the highest risk of hidden ear diseases.
RVC’s latest discovery confirms previous research, which had initially suggested that lop-eared rabbits might be more susceptible to ear disease. However, these studies had relied on small samples, retrospective clinical records and owner reports.
Although ear disease is widely recognised in rabbits, their health problems can often go unnoticed since they rarely display signs of discomfort. This can mean issues such as excessive ear wax, narrowed ear canals, and early signs of ear disease can go unnoticed without veterinary examination.
In this study, researchers conducted a large, systematic assessment of how ear shape and head shape might relate to ear abnormalities. This was intended to provide both veterinary surgeons and rabbit owners with a more robust understanding of the condition.
Between October 2023 and February 2024, RVC Rabbit Welfare Research Assistants examined 435 pedigree rabbits volunteered by British Rabbit Council (BRC) breeders. Researchers travelled to BRC shows and breeding studs, where they recorded rabbits’ ear type, head shape, estimated adult bodyweight, age, and other features.
They then performed a structured otoscopic examination, which saw them examine the outer ear, the diverticulum and the full length of the external ear canal for signs of inflammation, narrowing, discharge or crusting.
By linking these examinations with statistics, the team compared ear health across 49 breeds to link conformations with specific ear abnormalities.
Lop-eared rabbits were found to be more likely to show nine of the 11 abnormalities assessed. This included ear canal narrowing, abnormal colour, flaky and wet discharge, behavioural reactivity, dermatological changes to the pinna, and crusts in the diverticulum.
Such abnormalities indicate painful inflammation or infection to the outer ear canal, which can seriously impact welfare.
Head shape was also indicative of potential ear problems, however this was not as consistent as with ear shape. For example, brachycephalic rabbits had narrower ear canals, while dolichocephalic rabbits might get more crusts in the diverticulum.
Body size was similarly relevant, with heavier rabbits most likely to display redness, narrowing, flaky discharge, traumatic pinna changes and strong behavioural reactions to examination.
Maria Jackson, Rabbit Welfare Research Assistant at RVC and lead author, said: “Our findings have once again shown that rabbits with lop ears are more likely to develop ear problems – specifically, signs of otitis externa – than rabbits with upright ears. Rabbit owners should take their rabbit for regular veterinary examinations, where the ears will be checked with an otoscope for hidden signs of disease.
“Anyone owning a lop-eared rabbit must be especially vigilant for subtle signs of ear pain, such as scratching the ears or shaking the head more than normal, and general lethargy or withdrawal.”
The full study can be found in the Veterinary Journal.
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