Abortion Flashcards
Zygote
Product of conception
Embryo
Defines embryonic mass
Not yet reached stage of differentiation
Can’t identify the species
Fetus
After completion of differentiation
Occurs similar time to mineralisation
Resorption
Loss of embryo
Prior to differentiation
Abortion
Loss and expulsion of fetus post differentiation
What would happen is PGF2a is given when CL is primary structure?
Loss by resorption/abortion
If given after L-P shift nothing will happen
What happens when fetus dies when CL is present?
CL will continue to produce progesterone
Fetus will stay in uterus and fluid will be resorbed
* Mummification occurs
What happens if fetus dies after L-P shift?
No signal to keep fetus inside dam
Expulsion/abortion occurs
What happens if embryo is lost prior to mineralisation
Resorption of embryo - no expulsion
Expulsion/abortion
Requires decline in progesterone and onset of uterine contractions
○ Death after L-P shift
Mummification
○ Maintenance of progesterone with rapid absorption of fluid from fetus
○ Dehydration of fetus
○ Death before L-P shift
Maceration
○ Autolysis/purification of dead fetus that has not be expulsed
Due to obstruction to expulsion
○ Bacteria invade
Stillbirth
Fetus reaches term but dies during parturition
Non-infectious causes of pregnancy loss
○ Genetic abnormalities
○ Uterine disease - not able to form effective placenta
○ Stress
Nutritional
Heat
○ Maternal illness
○ Nutritional phytotoxins
Infectious causes of pregnancy loss
○ Exposure of the pregnant female to reproductive pathogens
Often viruses or bacterial [but also neospora, trichomonas, fungal etc]
Many of these are not venereal transmission
○ Recrudescence of latent viral infections
○ Ascending infection
E.g. placentitis
○ Few bacterial venereal pathogens cause pregnancy loss
They do cause endometritis
E.g. CEM in mares = endometritis only
E.g. Campylobacteriosis in cattle = endometritis but if persists some abort
