Genetic and environmental factors influencing tooth and jaw malformations in rabbits.

Tooth alterations of 281 rabbits from 10 different breeds were evaluated, starting at the age of three weeks until they were fully grown. All rabbits were kept in an outdoor facility, fed with a pelleted diet and had free access to water and hay. The most common finding in 3182 clinical examinations was a gap between the mandibular incisors (38 per cent). Skull X-rays from 4 adult breeding rabbits, 15 offspring with clinical signs of dental disease and 12 clinically healthy siblings were assessed by two different methods using cephalometric distances and anatomical reference lines. Repeatabilities of cephalometric distances were mostly low and no significant associations to tooth health were found. The anatomical reference lines revealed dental findings even in rabbits that were graded as tooth healthy in previous clinical examinations. On the basis of the demonstrated age-dependent development of tooth and jaw malformations a first examination and selection at the age of 12 weeks can be recommended. Also genetic aspects for tooth and jaw malformations were considered. The estimated heritability for brachygnathia superior was 0.254 ± 0.169 for all examinations and 0.105 ± 0.092 comprising the last examination of each rabbit when fully grown.