Ear health and quality of life in pet rabbits of differing ear conformations: A UK survey of owner-reported signalment risk factors and effects on rabbit welfare and behaviour

Evaluation of Lateral Ear Canal Ablation (LECA) as a Surgical Treatment Option for External Ear Canal Disease in Lop-Eared Pet Rabbits (Oryctolagus cuniculus)

A soft tissue-filled external ear canal, sometimes also referred to as otitis externa in the veterinary literature, is a prevalent disease in pet rabbits, especially in lop-eared pet rabbits. The authors describe the clinical findings, diagnostic workup, therapy, and outcome of pet rabbits treated surgically for a lateral ear canal ablation (LECA). For the time period between 2015 and 2023, the medical records of two veterinary clinics were evaluated retrospectively. A total of 25 pet rabbits, diagnosed via computed tomography (CT) scans with a soft tissue-filled external ear canal and (if present) middle ear, were identified. All the pet rabbits were evaluated as lop-eared pet rabbits and all were treated surgically using the same surgical technique, LECA. In accordance with Richardson et al., we categorized the different ear filling levels by using the grading system that was established in 2019. The mean follow-up period was 19 days, and in one case complete wound healing was not reached within 131 days after surgery. A total of 7/25 of the pet rabbits were evaluated with wound healing issues. Of the cases, 18/25 did not develop any recurrent ear diseases. Loss to follow-up was observed in 5/25 of the cases and recurrent ear diseases were identified in 2/25 of the pet rabbits. Progression of the ear disease was detected in four cases. CT post-operative images were acquired for 14/25 of the pet rabbits. Based on this study, LECA can be considered a safe surgical method to treat soft tissue-filled external ear canals, especially in lop-eared pet rabbits. Nonetheless, thorough post-surgical management including wound control is critical for therapy success.

Cytological evaluation, culture and genomics to evaluate the microbiome in healthy rabbit external ear canals

BACKGROUND

Lop-eared rabbits may be predisposed to otitis externa (OE) as a consequence of their ear conformation. Although otoscopy, otic cytological evaluation and culture are valuable tools in dogs and cats, published data on rabbits remain lacking.

HYPOTHESIS/OBJECTIVES

This study aimed to assess the utility of otoscopy and cytological results in evaluating healthy rabbit external ear canals (EECs) and to characterise ear cytological and microbiological findings through culture techniques and metagenomic sequencing.

ANIMALS

Sixty-three otitis-free client-owned rabbits.

MATERIALS AND METHODS

All rabbits underwent otoscopy and ear cytological evaluation. In a subset of 12 rabbits, further bacterial and fungal culture, fungal DNA assessment and metagenomic sequencing were performed.

RESULTS

Otic cytological results revealed yeast in 73%, cocci in 42.9% and rods in 28.6% of healthy rabbit EECs. Compared to upright-eared rabbits, lop-eared rabbits had more discharge and more bacteria per oil immersion field. Culture isolated eight different species yet metagenomic sequencing identified 36, belonging to the Bacillota (Firmicutes), Pseudomonadota and Actinomycetota phyla. Staphylococcus were the most commonly observed species with both methods. Ten of 12 rabbits were yeast-positive on cytological evaluation with only three yielding fungal growth identified as Yarrowia (Candida) lipolytica, Eurotium echinulatum and Cystofilobasidium infirmominiatum.

CONCLUSIONS AND CLINICAL RELEVANCE

Healthy rabbit EECs lack inflammatory cells yet can host yeast and bacteria, emphasising the need to evaluate cytological results alongside the clinical signs. Lop-ear anatomy may predispose to bacterial overgrowth and OE. Notably, yeasts may be present despite a negative culture.

Conformation-associated health in pet rabbits in the UK: A VetCompass cohort study

BACKGROUND

Domestic rabbit breeds vary substantially from the wild rabbit body type. However, little is known about how the conformation of pet rabbits influences their health.

METHODS

Data were extracted from VetCompass anonymised clinical records of rabbits under UK primary veterinary care during 2019.

RESULTS

The study included 162,107 rabbits. Based on 88,693 rabbits with relevant breed information recorded, skull shape was classified as brachycephalic (79.69%), mesaticephalic (16.80%) and dolichocephalic (3.51%). Based on 83,821 rabbits with relevant breed information recorded, ear carriage was classified as lop-eared (57.05%) and erect-eared (42.95%). From a random sample of 3933 rabbits, the most prevalent disorders recorded overall were overgrown nail(s) (28.19%), overgrown molar(s) (14.90%) and obesity (8.82%). Compared to those with a mesaticephalic skull shape, brachycephalic rabbits had lower odds of obesity, anorexia and gastrointestinal stasis and higher odds of perineal faecal impaction, tear duct abnormality and haircoat disorder. Compared to erect-eared rabbits, lop-eared rabbits had higher odds of perineal faecal impaction and tear duct abnormality.

LIMITATION

A large proportion of records with incomplete breed information hindered full analysis for breed-related and conformation-related attributes.

CONCLUSION

Limited evidence for major links between skull shape or ear carriage conformations and overall disorder risk suggests that factors such as husbandry or even just living life as a domesticated species may be bigger drivers of common health issues in pet rabbits in the UK.

Dental disease in companion rabbits under UK primary veterinary care: Frequency and risk factors

BACKGROUND

Some prior evidence has suggested that lop-eared rabbits and those with brachycephalic skull conformations have a higher dental disease risk. This retrospective cohort study reports the frequency and conformational risk factors for primary-care veterinary diagnosis with dental disease in companion rabbits in the UK.

METHODS

Anonymised VetCompass clinical records were manually reviewed to confirm dental disease cases. Risk factor analysis used multivariable binary logistic regression modelling.

RESULTS

From 161,979 rabbits under primary veterinary care in 2019, the 1-year period prevalence of overall dental disease was 15.36% (95% confidence interval [CI]: 14.78-15.96). The prevalence of dental disease affecting incisors was 3.14% (95% CI: 2.87-3.44), and for cheek teeth it was 13.72% (95% CI: 13.17-14.29). Neither lop-eared conformation nor brachycephalic skull conformation was significantly associated with increased odds of dental disease. Dental disease odds increased as age increased and decreased as bodyweight increased.

LIMITATIONS

This study retrospectively accessed clinical records, so breed names may sometimes be imprecise.

CONCLUSION

The high overall prevalence of dental disease represents a major welfare concern for all companion rabbits, regardless of conformation. This information can be used to encourage regular routine dental assessment of rabbits of all conformations to promote earlier diagnosis, paying particular attention to older rabbits and those with low bodyweight.