URINARY STEROID EVALUATIONS TO MONITOR OVARIAN-FUNCTION IN EXOTIC UNGULATES .10. PREGNANCY DIAGNOSIS IN PERISSODACTYLA

Enzymeimmunoassays (EIAs) for estrone conjugates (EC), pregnanediol-3- glucuronide (PDG), and C-19 and C-21 progesterone metabolites (C-19/C- 21) were used to analyze urine samples from four nondomestic equid spe cies, four tapir species, and two rhinoceros species in an attempt to identify if these assays could be used for diagnosing and monitoring p regnancy. The same urine samples were also analyzed for the presence o f equine chorionic gonadotropin (eCG) activity, using a field dipstick test and a radioimmunoassay (RIA). The EC EIA was validated for three equid species and the Malayan tapir, Neither the PDG nor the C-19/C-2 1 EIAs were validated in any species evaluated. In equid species, the EC EIA demonstrated a specificity (the percentage of nonpregnant sampl es identified correctly) of 100% and a sensitivity (the percentage of pregnant samples identified correctly) of greater-than-or-equal-to 88% . With the exception of the Grevy's zebra, the C-19/C-21 EIA showed a similar accuracy in identifying pregnant and nonpregnant equids. The P DG EIA was not sufficiently accurate to merit its use in equids or tap irs for pregnancy diagnosis. From the data collected, it appears analy sis of a single urine by both the EC EIA and the C-19/C-21 EIA would b e the best method of pregnancy detection during the last 2 trimesters of gestation, in equid species. In tapirs, the C-19/C-21 EIA was sligh tly more accurate for pregnancy diagnosis than the EC EIA. The C-19/C- 21 EIA had a specificity of 93%, but a sensitivity of only 73% in tapi r species. None of the EIAs evaluated demonstrated a sufficient specif icity or sensitivity to be useful, as presently performed, for pregnan cy diagnosis from a single sample in the black rhinoceros. The eCG dip stick used in this study did not prove a sufficiently reliable test fo r routine pregnancy in nondomestic equids. The eCG RIA results in the Przewalski's horses and the Hartman' s mountain zebra were positive ea rly in gestation, and indicate that gonadotropin analysis may be usefu l for pregnancy detection in these species. Only very low amounts of e CG activity was measured by the eCG RIA in the tapir and rhinoceros ur ine samples. (C) 1994 Wiley-Liss, Inc.