DANTAS, F. P. M.; http://lattes.cnpq.br/5215256704216932; DANTAS, Francelicia Pereira Marques.
Resumo:
This paper reports a new form of chodrodysplasia in sheep from Brazilian hair
sheep of the Cabugi breed, also known as “cara curta” (short head). This breed is
characterized by short head and sometimes the animals are slighter smaller and more
compact that animals from similar breeds. Dwarf lambs that died in 2-6 months after birth
are frequent in this breed. In a flock of 68 ewes and 3 rams of the Cabugi breed, 39 lambs
were born. From these 5 (12,8%) had marked dwarfism and died or were euthanized. From
the other 34 lambs 10 (25,6%) had a normal face, and 24 (60%) had the short face
characteristic of the Cabugi breed. Dwarf lambs were much smaller than normal, with
short legs, a domed head with retruded muzzle and slightly protruded mandible, sternal
deformities and exoftalmic eyes situated more lateral in the face than normal. Four dwarf
lambs were euthanized and necropsied and one was necropsied after the spontaneous
death. Histologic examination of the long bones of the limbs, basocranial bones and
vertebrae showed mild disorganization of the growth plates with increased resting cartilage
and shorter and disorganized proliferative and hypertrophic cartilage. Smaller amount of
bone were observed in the primary and secondary spongiosa, and metaphysis when
compared with a control lamb of the same age. It is suggested that the disease, is a
hereditary chondrodysplasia caused by a recessive gene; homozigotes have marked lethal
dwarfirm, but the disease is also partially expressed in all animals with the characteristic
short face of the Cabugi breed, which are in heterozygotes.