Congenital absence of tail in calves have been reported by Lotfi and Shahryar (2009) and Williams (2010) but in our case, the animal was having a tail with only five coccygeal vertebra
associated with rat tail syndrome.
In the current study sacrum with five pairs of sacral foramina are formed due to complete bilateral fusion of fifth lumbar vertebra with the first sacral vertebra or complete bilateral fusion of first coccygeal vertebra with fifth sacral vertebra (Sacralization of fifth lumbar vertebra or sacralization of first coccygeal vertebra), the sacrum consisting of six segments.
The prevalence of the sacralization of fifth lumbar vertebra varies from 1.7% to 14% [10,11] and sacralization of first coccygeal vertebra varies from 7.8% to 37% in different populations by origin.
Similarly, at the caudal end, first coccygeal vertebra
when fuses with the apex of sacrum is known as sacralization of coccygeal vertebra