Fetal death may be followed by expulsion (abortion of a fresh or autolyzed, fetus) or retention in utero (fetal mummification). In cases of abortion, luteolysis occurs and the hormonal support of pregnancy is lost. The animal normally shows signs that pregnancy has terminated. An aborted fetus may be found, the dam may have abnormal vaginal discharge, and may return to estrus.
In cases of fetal mummification (irrespective of the cause), fetal death (usually between 3 and 8 months) is often not immediately apparent. In such cases, the corpus luteum persists in the ovary because there is no viable fetus to initiate the onset of parturition and no inflammatory response in the endometrium-releasing prostaglandins, and there is no vaginal discharge and no signs of estrus. The abnormal pregnancy in such animals continues indefinitely. Clinical examination reveals that the fetus is dead, although the dam is pregnant. Transrectal palpation reveals an irregularly shaped, contracted uterus with a fetal mass but no fetal fluid within it. There is no fremitus in the uterine artery. Ultrasonographic Ultrasonography in Animals Ultrasonography is the second most commonly used imaging format in veterinary practice. It uses ultrasonic sound waves in the frequency range of 1.5–15 megahertz (MHz) to create images of body... read more examination of accessible parts of the uterus per rectum confirms the diagnosis.
The abnormal pregnancy can be terminated by a single IM injection of prostaglandin F2alpha. The fetus is expelled from the uterus and can be manually removed from the vagina 48 hours later.
In sheep, fetal mummification can be diagnosed by abdominal palpation supported by transabdominal ultrasonography. Affected animals are normally culled due to economic considerations. Treatment can be attempted as for cattle.