Objective—To determine whether gavage of pregnant
mares (housed without access to pasture) with
starved eastern tent caterpillars (ETCs) or their excreta
is associated with early fetal loss (EFL), panophthalmitis,
Design—Randomized clinical trial.
Procedure—15 mares with fetuses from 40 to 80
days of gestation (dGa) were randomly assigned to
1 of 3 groups and received 2.5 g of ETC excreta, 50
g of starved ETCs, or 500 mL of water, respectively,
once daily for 10 days. Mares were housed in
box stalls, walked twice daily, and not allowed
access to pasture for 12 days before or during the
Results—4 of 5 mares gavaged with starved ETCs
(group 2) aborted on trial days 8 (2 mares), 10, and
13. No control mares or mares that received excreta
aborted. Differences between the ETC group and
other groups were significant. Abortion occurred on
49, 64, 70, and 96 dGa. Allantoic fluids became
hyperechoic the day before or the day of fetal death.
Alpha streptococci were recovered from 1 fetus and
Serratia marcescens from 3 fetuses. Neither
panophthalmitis nor pericarditis was seen. The abortifacient
component of the ETCs was not elucidated.
Conclusions and Clinical Relevance—These findings
suggest that mares with fetuses from 40 to 120 days
of gestation should not be exposed to ETCs because
they may induce abortion. (J Am Vet Med Assoc 2004;
Objective—To assess survival-to-discharge rates of mares and foals and postoperative complications and fertility in mares following cesarean section (C-section).
Design—Retrospective case series.
Procedures—Medical and breeding records of mares that underwent C-section were reviewed; signalment, surgical technique, complications, survival-to-discharge rate, and pregnancy and foaling rates were recorded and evaluated. Foaling rates in the 3 years after C-section were compared with the cumulative foaling rate before C-section.
Results—C-section was performed because of dystocia (n = 71) or concurrent maternal disease (20) or was elective (4). Overall survival-to-discharge rate was 84% (80/95) for mares and 35% (28/80) for foals. Six of 15 mares that had partial fetotomies prior to C-section did not survive. Mares that had dystocia for < 90 minutes had the fewest complications. Cumulative foaling rate before C-section was 77% (394/509). Overall foaling rate for the 3 years after C-section was 52% (30/58) and 68% (13/19) when duration of dystocia was ≥ 90 minutes and < 90 minutes, respectively, and was 31 % (9/29) for mares ≥ 16 years old. Foaling rate was significantly lower for mares bred in the same year as C-section than for mares bred in later years.
Conclusions and Clinical Relevance—Breeding in the same year as C-section, dystocia for ≥ 90 minutes before C-section, and mare age ≥ 16 years were associated with poor foaling rates. Prognosis for delivery of a live foal in years following C-section was good if duration of dystocia was < 90 minutes and the mare was < 16 years old at the time of surgery.