Lecture 10: Pregnancy Loss in the Mare & Accidents of Gestation

Question 0

management of luteal insufficiency

Answer 0

progestin supplementation (regumate):

• until normal luteal function is confirmed
• until fetal placental unit takes after progesterone production for maintenance of pregnancy (day 80 - 120)

Question 1

secondary luteal insufficiency: 3 causes

Answer 1

1. endotoxemia - colic or gram negative infection: causes prostaglandin release (lyses CL)
2. persistent endometritis (PGF release)
3. endometrial cysts: blocks embryo movement mare wont recognize pregnancy and causes luteolysis

Question 2

why do mares abort twin pregnancies?

Answer 2

placental insufficiency - death of one twin precipitates the premature delivery of both

Question 3

** management of twin pregnancies **

Answer 3

** manual reduction - 90% success rate if performed prior to day 20 **

** spontaneous reduction - only occurs in UNILATERAL twins (80% of the time)

other methods: transvaginal aspiration of fetal fluids and fetal heart injection of KCl

Question 4

** long/twisted umbilical cord - how do you diagnose it? **

Answer 4

need to see circulatory changes in cord to diagnose: edema, congestion and thrombosis

Question 5

EHV-1 causes, dx, and ** prevention **

Answer 5

causes: abortion several weeks after maternal infection, rspiratory and neurologic disease
dx: viral isolation and histopath of fetus and placenta (no serology)

** prevention: pregnant mares should be vaccinated on months 3, 5, 7 and 9 –> prevents abortion storms **

Question 6

** EVA (equine viral arteritis) causes and transmission **

Answer 6

causes: a myositis of uterine musculature –> compress uterine musculature –> fetal anoxia
- also mild systemic/respiratory disease
- no effect on fertility or EED (early embryonic death)

transmission: air-borne to late pregnant mares may cause abortion. venereal transmission from stallion (chronic carriers). will persist in frozen semen

Question 7

** EVA dx and prevention **

Answer 7

dx: submit fetus, placenta and a paired blood sample from the dam for serology
prevention: vaccinate all stallions, 1005 seroconversion

Question 8

bacterial placentitis

Answer 8

most common cause of abortions in the US
- ascending infection: may also be hematogenous spread

clinical signs: vaginal discharge, premature lactation

dx: transvaginal ultrasound - CTUP and placental separation, acute phase proteins (SAA, haptoglobin), estrogen, microRNA, alpha-fetoprotein

Question 9

how do you dx nocarida-like placentitis?

Answer 9

transabdominal ultrasound - the lesions are located AWAY from the cervical star

Question 10

uterine torsion: how does it present, how do you dx, how is treated?

Answer 10

• torsion is cranial of cervix

presented: with signs of colic
dx: rectal palpation - displacement of the braod ligament

tx: surgical, non-surgical

Question 11

rupture of the prepubic tendon: clinical signs, tx, prognosis

Answer 11

• sudden onset
• clinical signs: “dropped abdomen”, pain, forward tilted pelvis
• tx: control pain, support abdomen, induce if foal is mature, always attend parturition

prognosis: may be life-threatening for mare and foal, mare should not carry a foal again, embryo transfer may be used to save mare’s reproductive future