Pregnancy Termination in Companion Animals

Abstract

Despite a large body of research and numerous review papers on the subject, there is still a great disparity in treatment protocols for mismated companion animals in the USA and elsewhere. Numerous treatment protocols are available. Ovariohysterectomy has the advantage of permanently removing the risk of an unwanted pregnancy. Medical treatments have varying side effects, depending on the protocol selected, and depend on owner vigilance to prevent future pregnancies. Medical treatment is most often performed in early gestation or mid-gestation. Pregnancy termination after fetal ossification results in abortion of non- viable or poorly viable fetuses.

Early treatment, prior to or shortly after onset of diestrus, results in resorption of fetal fluids and tissues without vulvar discharge, but must be done prior to pregnancy diagnosis. Treatment protocols for pregnancy termination at this stage are associated with more side effects than those for mid-gestation. Pregnancy termination after ultrasonographic confirmation in mid-gestation may result in resorption of all fetal tissues or in expulsion of bloody discharge. Delaying medical treatment until after pregnancy diagnosis minimizes drug risks by avoiding treatment of non-pregnant animals and through the use of lower doses of medication. Several protocols for pregnancy termination at this stage are discussed in detail in this review article. [...]