Radiographic evaluation of diaphragmatic defects in golden lion tamarins (Leontopithecus rosalia rosalia): Implications for reintroduction

Diaphragmatic defects of suspected familial origin have been documented in captive golden lion tamarins (Leontopithecus rosalia rosalia). This defect was of concern to a multidisciplinary reintroduction program. Plain radiographs taken prior to reintroduction failed to identify an individual with a hernia. A radiographic technique using an inverted contrast peritonealogram was developed using an i.p. injection of radiopaque contrast medium to outline the abdominal contour of the diaphragm when the anesthetized tamarin was in an inverted (head down) position. The inverted contrast peritonealogram was used to evaluate the diaphragmatic contours of 260 golden lion tamarins (155 from the National Zoological Park, Washington, D.C., 10 from the Rio de Janeiro Primate Center, and 95 free-living in the Poço das Antas Reserve, Brazil). The diaphragmatic contours ranged from smooth and symmetrical to variations of a wavy appearance, out-pocketing, and/or differential elevations of the hemidiaphragm. No true diaphragmatic hernias were detected, but the more severe abnormalities in the diaphragmatic contour were consistent with eventration of the diaphragm. The diaphragmatic contours were graded from 0 to 5 based on the type and degree of irregularity present. The highest grade observed in the 95 free-living golden lion tamarins was 3, seen in only two individuals (3%) compared with 55 individuals (35%) with a grade 3 at the National Zoological Park. This comparison precipitated the decision that no golden lion tamarin with a diaphragmatic contour of grade 4 or 5 (considered a major defect) would be reintroduced. This decision was made in an attempt to minimize the effect of the potential deleterious diaphragmatic defect on survival of this species in the wild.