Clinical Approach to Abortive Disease Flashcards
what are the three stages of abortive disease
- early embryonic death
- abortion
- stillbirth
what are the ranges of early embryonic death in cows, horses, dogs
cows: <42 days
horses: <40 days
dogs: <20 days
what are the ranges of abortion in cows, horses, and dogs
cows: 42-260 days
horses: 40-320 days
dogs: 20-57 days
what are the ranges of stillbirth in cows, horses, and dogs
cows: >260 days
horses: >320 days
dogs: >57-72 days
what are the three mechanisms of pregnancy loss
- loss of luteal function
- loss of placental support
- fetal disease
what are two causes of loss of luteal function
- failure of recognition of pregnancy
- premature increased prostaglandins
what is failure of MRP and what species does it occur in
inability to establish recognition of pregnancy which leads to early luteolysis
occurs in horses and ruminants
- horses: embryo no longer able to migrate
- ruminants: failure to elongate and secrete interferon tau
what causes a premature increase in prostaglandins
systemic illness or iatrogenic administration
at what stage in gestation can a premature increase in prostaglandins affect pigs/goats/dogs/camelids
entire pregnancy
at what stage in gestation can a premature increase in prostaglandins affect sheep, horses, and cats
prior to the establishment of placental progesterone
at what stage in gestation can a premature increase in prostaglandins affect cows
early and late pregnancy (when CL is still required)
what are two causes of loss of placental support
placental insufficiency or placentitis
placental insufficiency
inability of the placenta to support the fetus
- uterine disease (CEH, endometrial fibrosis, amyloid infiltrate of caruncle)
- twins in horses
- umbilical torsion
causes of placentitis
- hematogenous (most common in most species)
- ascending infection (most common in horses)
what are examples of fetal disease that cause pregnancy loss
- fetal distress –> premature cortisol release
- fetal infection
- congenital defects
- chromosomal abnormalities
abortion rate
of observed OR presumed aborted / # of diagnosed pregnant
range animals - can use # of females exposed to male as an estimate of number pregnant
litter bearing - can used # fetuses affected / total # fetuses
endemic abortion rate
expected frequency of abortion for a given species
epidemic abortion rate
higher than expected frequency of abortion for that given species
sporadic abortion
irregular, infrequent (individual) abortions
what are other factors to consider in a sporadic case of abortion
- zoonotic risk
- risk to other pregnant species
- risk to pregnant herdmates
- intermediate/host vectors
what are common presenting complaints with abortive disease
- prolonged interestrus intervals
- abortions
- stillbirths/neonatal mortality
- low birth rates
- interrupted/unexpected birthing distribution
observed vs actual abortive rate
true # of abortions is usually = 2.2-5x the observed # of abortions
what are non-infectious causes of fetal attrition
- iatrogenic (PGF2a, estrogens)
- stress/trauma
- systemic illness of the dam
- nutrient deficiencies
- estrogenic mycotoxins
- toxic plants
- developmental errors
what are infectious causes of fetal attrition
gets into the placenta or fetus
1. viral
2. bacterial
3. protozoal
4. fungal
