Rabbit conformational predispositions to ear abnormalities: field study of a pedigree population

Supporting dataset for 'Rabbit conformational predispositions to ear abnormalities: field study of a pedigree population'.Abstract: Lop-eared conformation has previously been associated with rabbit ear disease in clinical populations. Here, we investigated conformational and signalment risk factors for ear abnormalities in a field study of pedigree rabbits. Ears of breeder-volunteered rabbits were examined with an otoscope at British Rabbit Council shows and studs, and risk factor analysis performed with linear and binary logistic modelling. Inter-observer reliability was Substantial–Excellent for most variables. From 435 rabbits examined, lop-eared rabbits had increased scores and odds for 9/11 ear abnormalities tested compared to erect-eared rabbits. These abnormalities included abnormal ear canal colour (P<0.001), ear canal stenosis (P<0.001), flaky discharge in the upper canal (P<0.001), wet discharge in the upper (P=0.035) and lower canals (P<0.001), crusts or red discharge (P<0.001) in the upper ear canal, and behavioural reactivity to ear examination (P=0.050). More dolichocephalic rabbits had higher odds of diverticulum crusts (P=0.013), whilst more brachycephalic rabbits had higher scores for ear canal stenosis (P=0.008). Heavier breeds had higher risks of some ear abnormalities, whilst other conformation and signalment risk factors showed contradictory results. Lop-eared rabbits were significantly predisposed to ear abnormalities suggesting otitis externa, whilst brachycephaly appeared less important in the aetiology of otitis externa than sometimes thought. Breeders, owners, and veterinarians must be vigilant for ear disease signs, especially in lop-eared rabbits. Ear canal discharge type could not be determined without cytology and formal ear disease diagnosis was not possible in this field study, although most abnormalities were suggestive of otitis externa.