The anti-peptide relaxin antibodies for monitoring the well-being of the fetus in pregnant bitches

Abstract

Pregnancy management is difficult in canines and there is a lack of methodology which would allow monitoring embryonic well-being. Relaxin (Rlx) is being reported for use in pregnancy diagnosis in different species. Here, we evaluated seven anti-Rlx peptide antibodies for detection of well-being of the fetus in bitches. Peptides were synthesized using solid phase peptide synthesis chemistry and the hyper-immune sera raised in chicken against peptides. In sandwich enzyme linked immunsorbent assay (ELISA), the chicken anti-Rlx P4 as a capture and rabbit anti-prorelaxin as detection antibody, gave better results in terms of differentiating the pregnant from non-pregnant bitches. Thirty five canine serum samples (21 non-pregnant, 11 pregnant and 3 males) were screened. Among the 11 pregnant, six delivered normally and the rest of the bitches aborted a few days after the serum collection with one or two dead fetuses. Among the 11 pregnant serum samples, 4 showed the absorbance above the cut-off value set for pregnancy, which delivered healthy puppies and five bitches showed the absorbance below the set cut-off value aborted after a few days of blood collection with one or two dead fetuses. The specificity of the assay was found to be 90.47% and the sensitivity of the assay for detecting the well-being of the fetus is 82%. The serum samples collected from those bitches having problems related to normal whelping, had shown absorbance below the set cut-off value. The results of the study indicate that relaxin is a useful marker, specifically for monitoring the pregnancy and tells about the well-being of the fetus.