PHA in Dexters

Hydrops fetalis associated with pulmonary hypoplasia in Dexter calves - Abstract
PA WINDSOR, JAL CAVANAGH and I TAMMEN
Faculty of Veterinary Science, University of Sydney, Camden, New South Wales

"The occurrence of severe fetal dystocia due to hydrops fetalis associated with pulmonary aplasia in two male and pulmonary hypoplasia in one female Australian Dexter fetuses from two herds is described. Obstetrical intervention by caesarean section was required for delivery of the fetuses, with mortalities in one dam and the 3 calves. Clinical, pathological and genetic features are tabulated to assist in distinguishing pulmonary hypoplasia-associated hydrops fetalis from the more prevalent disorder of chondrodysplasia in Dexter cattle. Anasarca and complete absence or presence of only rudimentary lung tissue in a large thoracic cavity clearly distinguishes this entity from the lesions of Dexter chondrodysplasia that include severe micromelia and abundant lung tissue in a small thoracic cavity with shortened spine and rib cage. Pedigree information suggested that Dexter hydrops may be transmitted in an autosomal recessive manner."

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This is caused by an abnormal gene and has also been found in other breeds of cattle. We recently had confirmation of pulmonary hypoplasia with anasarca (PHA) with some Dexters here in the U.S. Pulmonary hypoplasia in general means underdeveloped and poorly formed lungs while anasarca translated means retained fluid. Usually this results in a calf being born dead and severe cases can result in the death of the cow. Since the aborted calf may sometimes have the appearance of a "bulldog" calf this may be why on occassion there's been reports from a breeder believing they had a "bulldog" from a tested free of chondrodysplasia Dexter.

The exciting news is that they just discovered the marker in Dexters which means this can be tested for. So while testing for chondrodysplasia, Bova Can labs will likely be able to also run a Dexter PHA test at the same time saving the expense of having to have two tests.