Diagnosis of agricultural animal abortion
Maintenance of a profitable livestock industry depends upon efficient animal reproduction. Diseases that interrupt pregnancy are costly, and control measures cannot be devised until the cause for the reproductive loss is accurately identified. Identifying the cause for abortion in agricultural animals, however, is a diagnostic challenge for clinicians and laboratory diagnosticians alike. The efficiency of diagnosing abortions in laboratories around the world varies widely, and, at best, 30-40% of fetal submissions result in a successful abortion diagnosis.
Why are abortion diagnosis success rates so low?
The low success rate of abortion diagnosis occurs for several reasons:
- Abortion results from an event that occurred weeks to months earlier, and the cause is not present at the time of abortion.
- The fetus is often retained for days or weeks after death and is expelled in a state of advanced postmortem autolysis, making lesion identification difficult.
- The placenta, which often harbors valuable diagnostic information, is often not available for examination.
- Toxic, nutritional, hormonal, and genetic causes of abortion are often not detectable in fetal tissues.
How can abortion diagnosis rates be improved?
Abortion diagnosis can be attained by knowledge of herd husbandry (primarily nutrition and environment), thorough sampling for laboratory examination, and utilization of current laboratory technology, such as PCR and immunohistochemistry, which can greatly aid the accuracy and rapidity of diagnosis. The cornerstone of consistent abortion diagnosis, however, will continue to be close cooperation among livestock managers, clinicians, and laboratory diagnosticians to uncover all clues that may lead to a specific diagnosis.