Congenital multi-organ malformations in a Holstein calf.

A 5-day-old female Holstein calf was necropsied because of lethargy, recumbency and anorexia. At necropsy, multiple gross defects were evident in several organs, including unclosed sutures of skull bones, asymmetrical orbits, doming of the skull bones, hydrocephalus, hydranencephaly, cleft palate, brachygnathia, ventricular septal defect, mitral valve dysplasia and rudimentary lungs. On microscopic examination, pulmonary hypoplasia was characterized by reduced number of alveoli, replacement of peri-bronchiolar smooth muscles with connective tissue and small masses of undeveloped cartilage around the small airways. The present report is the first description of the congenital pulmonary hypoplasia accompanied by numerous malformations in Holstein breed.