Bovine Pregnancy, Pt. 2 Flashcards
What is amorphous globosus? Why is it more common in cattle?
acardiac twin - spherical mass encapsulated by skin +/- hair containing undifferentiated organ systems or tissues
presence of placental vascular anastomoses, where 2 embryos are connected and one receives more oxygenation blood than the other one
How should a Freemartin with an amorphous globosus be examined?
careful evaluation of any expelled mass and fetal membranes and sexual phenotype of the neonatal calf
What is mummification? How far into gestation does it make it to? Why?
dehydration and compaction of a sufficiently mature dead fetus in utero
fetal death without luteolysis
- no viable fetus initiates onset of parturition
- no inflammatory response in endometrium that releases prostaglandins (no PGF2α = no luteolysis)
What are the 3 requirements for diagnosing mummification?
- fetal death in a NON-PYOGENIC environment (3-8 months)
- functional CL without luteolysis
- closed cervix (anaerobic)
What are the 4 major etiologies of mummification?
- any cause of sudden death - umbilical cord torsion
- viral - BVD, bluetongue
- protozoal - Neospora caninum, Tritrichomonas foetus
- bacterial - Leptospirosis
What are the 2 classifications of mummification?
- papyraceous - dry
- hematic - wet, uncommon
What is a major sign of mummification? What is felt on transrectal palpation? What seldom occurs?
prolonged gestation - no viable fetus = no recognition by cow
irregularly shaped, contracted uterus with a fetal mass but no fluid within it + closed cervix + CL
- vaginal discharge or odor (non-pyogenic!)
- spontaneous expulsion
What medical treatment is recommended for mummification? Surgical?
PGF2α - dilates cervix, uterine contraction = expulsion of fetus within 2-4 days common
flank laparotomy, colpotomy
What are the 6 steps of performing a colpotomy?
- epidural block
- lavage vagina
- induce pneumovagina by incising it lateral to the cervix at 2 and 10 o’clock
- penetrate the peritoneum
- exteriorize the uterine horn
- suture + Buhner’s/Caslicks
What causes maceration?
fetal death with insufficient cervical dilation, causing autolysis of the fetus —> able to reach luteolysis
What 3 clinical signs are indicative of maceration? What is felt on palpation?
- severe systemic illness associated with metritis and toxemia
- intermittent straining
- fetid vaginal discharge
sharp, bony fragments (bag of gravel)
What is the most common etiology of maceration? How is it treated?
chronic endometrial damage (poor breeding prognosis)
- delivery per vaginal with manual vaginal dilation
- salvage by slaughter or euthanasia
How common is hydrops allantois (hydrallantois)? What is it caused by?
~90% of hydrops cases
PLACENTAL insufficiency - reduced number of placentomes with concurrent adventitial placentation
How common is hydrops amnion (hydramnios)? What is it caused by?
5-10% of hydrops cases
impaired ability of the FETUS to swallow amniotic fluid, commonly due to craniofacial anomalies or neuromuscular disruptions
Who is responsible for hydrops allantois (hydrallantois)? When does it most commonly occur?
MATERNAL placentation problem = adventitial placentation
later gestation - fetus is larger and needs more nutrition that the faulty placentomes cannot give
What is the classic sign of hydrops allantois? What are 3 other signs?
tense, barrel/apple-shaped abdomen = unable to lay on side
- anorexia, dyspnea
- grossly normal fluid
- placentomes and fetus NOT palpable
What 2 cattle are predisposed to developing hydrops allantois?
- Bison crosses
- in vitro deprived calves (abnormal offspring syndrome)
What treatment is recommended for hydrallantois? What is prognosis like?
induction of parturition with PGF2α to decrease P4 from the CL and dexamethasone to decreased P4 from the placenta
poor —> maternal issue, will likely cause issues again, salvage slaughter recommended
What causes hydrops amnion? What are 2 clinical signs?
FETAL problem = slow accumulation of viscous fluid
- gross uterine distention resulting in a pear-shaped ventral abdominal stretch
- placentomes and fetus are palpable
What differential diagnosis for hydramnios should be considered? What is prognosis like?
twins can cause the same pear-shaped abdominal distension
good! —> caused by fetal issues like neuromuscular disease or maxillary distortion, cow will likely have normal pregnancies following
Hydrallantois vs. hydramnios:
What is hydrops fetalis? What is the cause?
pulmonary hypoplasia with anasarca (PHA) = generalized edema, dystocia, and pulmonary hypoplasia
lethal autosomal recessive disordery (single missense mutation) commonly seen in Australian Dexters, Maine-Anjou Shorthorns, Herefords, and belted Galloway cattle
When is vaginal prolapse most commonly seen? What are 3 etiologies?
last trimester, multiparous (recurrent!!)
- increased abdominal pressure
- increased circulated estrogen
- anomalies of the vaginal wall and cervix
What are 3 predisposing factors to vaginal prolapse?
- excessive vaginal fat
- beef breeds: Herefords, Shorthorns, primary in Bos indicus
- repeated superovulation
What are the 4 grades of vaginal prolapse?
- intermittent protrusion of vaginal floor when cow lies down (less pressure)
- protrudes continuously, occasionally the urinary bladder becomes trapped within the everted vagina
- entire vaginal mucosa and cervix protrude continuously though the vulvar lips and the urinary bladder is entrapped
- cervicovaginal eversion persists and the entire vaginal mucosal appears necrotic and fibrotic
How is vaginal prolapse different in Bos indicus?
cervical eversion only (no vagina)
What is prognosis like for vaginal prolapse? What are 2 retention procedures performed?
poor, commonly recurs = salvage slaughter
- temporary sutures until calving - Buhner stitch with Barth blowout stitch around the vulvar lips, Caslick’s suture to seal dorsal commisure, bootlace, horizontal/vertical mattress
- permanent - vaginopexy, cervicopexy into prepubic tendon = no closing, maintains vaginal tissue within body cavity
Buhner stitch:
- stitch on outer border of commissures
- temporary - maintain closure until calving is occurring
When does uterine torsion most commonly occur? What signs are seen? What is not seen?
at term, non-progressing parturition
consistent with imminent parturition
straining - cow is too tired at this point
Where is uterine torsion most common? What 2 things can be felt on palpation?
90-180 degree rotation caudal to the cervix
- broad ligament stretched and tight
- vaginal and vulvar twist
What are 3 options for uterine torsion treatment?
- rolling
- correction per vagina with a detorsion rod
- laparotomy via C-section
How does cow and mare uterine torsion compare?
COWS = at term, vaginal involvement common
MARES = mid-gestation, often without vaginal involvement
How should a right torsion be treated by rolling?
“plank in the flank”
lay cow down on her right side and flip her to the other side while someone is standing on a plank above the fetus —> rotates uterus aroung the non-moving fetus
How is a detorsion rod used?
wraps around feet of the fetus, making outer rotation possible
- needs access to the uterus!
Why may prolonged gestation in cattle be wrongly diagnosed by farmers?
- improper/incorrect AI records
- pasture bred = unsure of exact date of insemination
- abortion/lost fetus may not have been noticed
In what 2 situations is fetal pituitary hypoplasia common? Why does this cause prolonged gestation?
- Guernsey - inherited autosomal recessive
- small calves with severe craniofacial deformities
pituitary gland is unable to secrete ACTH, which allows the calf to produce cortisol as it becomes stressed (less room in uterus) and start the cascade of parturition
In what 2 situations is fetal adrenal hypoplasia common? Why does this caused prolonged gestation?
- Holsteins: inherited autosomal recessive
- large at birth with fetal hirsutism and overgrown hooves
adrenal gland is not induced by stress signals and secretion of ACTH = low cortisol = no start to the cascade of parturition
How does abnormal offspring syndrome cause prolonged gestation?
calves are left deprived of nutrients in vitro due to abnormal placentation, causing the production of a small fetus that is slower to feel stress, resulting in no trigger of partutition
