The Peripartum Ruminant (Ch 18) Flashcards
Uterine torsions are most common in ______. In this species, they most often occur during _______ and twist [clockwise or counter clockwise].
- Most common in cattle
- Occur during late 1st stage or early 2nd stage labor
- To the left/counter clockwise (57% are 180 to 270 deg)
Vaginal prolapse in cattle is primarily associated with _______.
elevated plasma estrogen concentrations during late gestation
Other causes include increased intra-abdominal pressure in late pregnancy, obesity, and poor vaginal conformation
What is ring womb and what species does it occur in?
- incomplete dilation of the cervix
- sheep and goats
When it occurs 7 to 14 days pre-term its called early dilation syndrome
Hydrops allantois (hydrallantois) occurs in (5-10% or 85-95%) of bovine hydrops and is associated with (Disease of the uterus or genetic/congentical defect of the fetus). The fetus and placentomes are palpable/not palpable.
85-95% (88%)
Disease of the uterus (placental dysfunction)
Non-palpable placentomes & fetus
Hydrops amnii (hydramnios) is 5% of cases and caused by defects of the fetus. Placentomes & fetus are palpable.
Normal heart rate of full-term lambs and calves
Lambs: 108 - 126 bpm
Calves: 90 to 120 bpm
(Foals): 60 to 90 bpm
Palpation and ultrasound findings after fetal death
Palpation: reduced fremitus in the uterine arteries and increased uterine tone
U/S: absence of fetal heart beat, thickening of uterine wall, incr echogenicity of chorioallantoic and amniotic fluid, alterted fetal posture/definition, reduced size of caruncles
What does measuring estrone sulfate in a cow or small ruminant tell us?
-Diagnose pregnancy in sm ruminants after 50 days and in cattle after 100 days
-Slow rise in 2nd trimester (day 90-210)
-Rapid rise in 3rd trimester about 10 days before
parturition
-Low after fetal loss, regardless of stage
Estrogen is synthesized by embryonic tissue and converted to estrone sulfate by the endometrium
How is surfactant deficiency diagnosed? How can it be treated/prevented preparturition/c-section
A lecithin/sphingomyelin (L/S) ratio of less than 2.0 from the amniotic fluid means the surfactant system is immature.
Steroids stimulate production of surfactant phospholipids by alveolar type II cells. Giving flumethasone (10 mg) or dinoprost/lutalyse (25 mg) 30 hours before c-section increases the L/S ratio
Viability of calves, lambs and kids induced in late gestation?
Calves: Good within 14 days of parturition date
Lambs & kids: poor greater than 5 days from parturition date
How do you induce parturition in ruminants?
What are major complications associated with inducing parturition?
Exogenous glucocorticoids such as Dexamethasone (20 to 30 mg in cattle, 10to 20mg in small ruminants) alone or in combo with prostaglandin F2a (25 mg in cattle, 15 mg in sm ruminants).
Usually calve within 72 hrs of tx with dex, or within 36 hours of tx with both.
Complications: retained placenta, mastitis, metabolic dz, reduced milk production
Viral causes of stillbirth in ruminants (6)
Infectious bovine rhinotracheitis virus Bovine viral diarrhea Border disease Bluetongue Akabane virus Cache Vallue virus
How is the fetus supplied with oxygen in utero?
- Placenta = respiratory organ
- High oxygen affinity of fetal hemoglobin vs adults
-Oxygenated blood delivered via umbilical vein –> portal vein –> 2/3 shunted via ductus venosus into caudal vena cava –> right atrium –> 50% shunts to left atrium via foramen ovale and 70% of flow to pulmonary artery shunts to aorta via the ductus arteriosus (remainder perfuses lung)
How do neonates begin breathing and oxygenating at birth?
- Some lung fluid evacuated via trachea at delivery, most absorbed via alveolar walls
- Umbilicus ruptures –> asphyxia triggers gasping/breathing/incr peripheral vascular resistance
- Pulmonary ventilation reduces pulmonary vascular resistance –> perfusion ventilated alveolar tissue
- Ductus arteriosus closed within 4-5 min by incr O2 sautration of blood
- Foramen ovale functionally closed within 5 to 20 min by incr blood pressure in left atrium (reversing right to left shunt)
-Transient (1 to 4 hrs) metabolic & resp acidosis due to anaerobic glycolysis in tissues during this transition
Do ruminants have any intrauterine transfer of immunoglobulins?
No. They are (mostly) agammaglobulinemic and immunologically naive at birth.
Pre-colostral serum IgM and IgG levels are low and an elevated level may indicate in utero infection.
What percent of stillbirths are associated with dystocia in cattle? What is the most common cause in heifers vs multiparous cows?
40 to 60%
Fetopelvic incompatibility in heifers
Weak labor secondary to hypocalcemia/uterine torsion/incomplete cervical dilation in multiparous cows
