7. diseases and accidents of gestation

when does early embryonic death / loss occur?

< 17-24 days post-AI

when does late embryonic death / loss occur?

> 17-24d, < 42d post-AI

when does fetal loss occur?

> 42 days post-AI

when does stillbirth / neonatal death occur?

within 48 hrs postpartum

what are problems caused by twins?

• ↑ abortion (especially unicornual twins)

• ↑ stillbirth

• ↑ periparturient disorders

  • dystocia, retained fetal membranes, metritis, DA / ketosis

• ↑ days open, ↓ subsequent fertility

• ↓ heifer replacements

plans for “treatment” of twins

• terminate pregnancy

• reduce to single pregnancy

  • risk of pregnancy loss

• dry off a week or two earlier

• most are managed as is, but may consider inducing abortion in unicornual twin pregnancies and leaving bicornual twins alone

what is fetal mummification?

• a sporadic disorder resulting from death and desiccation of the fetus & placenta with persistence of the CL

• occurs after fetal ossification, typically between the third and eight months of gestation

fetal mummification etiology

• can be caused by anything that kills the fetus but does not continue as a septic process

• ex. fetal anomalies and viruses

• only rarely associated with twins in cattle

signs of fetal mummification

• no abdominal distention

• no udder development

• failure to calve at the anticipated time (overdue)

diagnosing fetal mummification

• palpation

  • abdominal uterus

  • fixed cervix

  • firm, non-fluctuant uterine mass

• ultrasound — no fluid

• must absolutely rule out normal pregnancy from a later breeding

fetal mummification treatment

• cow may be immediately culled

• PGF2α — confirm complete abortion

• removal of mummified fetus via colpotomy or C-section

what is fetal maceration?

• describes the effect of dead fetal tissue softening due to bacteria digestion in utero

• septic condition

fetal maceration etiology

• any cause of fetal death complicated by ascending or hematogenous bacterial contamination

• failure of fetal expulsion after death with retention of the carcass partially or entirely within the uterus

signs of fetal maceration

• return to estrus

• geintal discharge

• abortion

• in second trimester and beyond, may be associated with partial abortion or amphysematous fetus

• cow may display vague signs of illness due to persistent and severe uterine infection

diagnosis & treatment of fetal maceration

diagnosis

• palpation / US

• vaginoscopy / endoscopy

• exploratory

treatment

• supportive care (antibiotics)

• delivery of fetus/parts if cervix is open

• uterine lavage

• surgery

• salvage

what is hydrallantois (hydrops allantois)?

• dramatic increase in allantoic fluid late in gestation — life-threatening disease

• 90% of bovine hydrops

hydrallantois etiology

placental dysfunction resulting from adventitious placentation characterized by ↓ number of placentomes (↑ size) and development of a more primitive villous placentation

signs of hydrallantois

can be mild or severe; related to volume

• bilateral distention of the abdomen

• distressed, anorectic, no rumen activity due to compression, dehydration, and constipation

• sacroiliac dislocation

• abdominal muscle / prepubic tendon rupture

• recumbent / dyspneic

diagnosing hydrallantois

what are other differentials to consider?

• history

• transrectal palpation / ultrasound

  • fluid fills abdomen (usually in contact with spine)

  • uterine wall feels too tight to distinguish fetal parts or ballot the fetus; fetus and placentomes cannot be felt

• differentials: twins, hydramnion, severe physiological edema, GI distention (e.g. bloat, vagal indigestion)

hydrallantois treatment

• induction

  • poor prognosis for cow, non for calf, likely to recur

• salvage is best option due to poor treatment outcomes

• humane considerations often dictate euthanasia or immediate slaughter

what is hydramnios (hydrops amnii)?

• slow accumulation of fluid within the amnion in the last half of gestation

  • limited fluid accumulation

• heifers have increased incidence

hydramnios etiology & signs

etiology

• congenital anomalies (e.g. craniofacial defects)

• fetal anomalies, bison bull x cow

signs

• mild unless fluid accumulation is severe

• pear-shaped abdomen

hydramnios diagnosis & treatment

diagnosis

• history

• rectal palpation / ultrasonography

treatment

• induction of abortion

• monitor and assist delivery as indicated

• avoid using same sire for future breedings

• fetus invariably defective & nonviable

factors that may contribute to vaginal / cervical prolapse

• genetic (Hereford, Brahman, and their crosses)

• late gestation (majority of cases)

  • hormonal milieu relaxes perineum

  • ↑ intra-abdominal pressure

• large calf & abdominal fill

• recumbency

• previous calving trauma

first degree (grade 1 eversion) prolapse

• small, intermittent protrusion of the vaginal floor (mucosa) only when recumbent

• tissue often becomes dehydrated & traumatized, and leads to grade 2 eversion

second degree (grade 2 eversion) prolapse

• continuous protrusion

• possibility of urinary bladder getting trapped in everted organ

• quickly progresses to grade 3

third degree (grade 3 eversion) prolapse

• cervix, vagina, and bladder are prolapsed

• constant straining

• exposed cervical mucous plug

• cervical seal may liquefy, allowing bacterial contamination of the uters, leading to placentitis and fetal death

fourth degree (grade 4 eversion) prolapse

• eversion of such duration that the entire vaginal mucosa appears necrotic and fibrosed

• extensive tissue necrosis with risk of sepsis and abortion

• peritonitis is a possible result

vaginal / cervical prolapse diagnosis

• visually obvious — rule out retained fetal membranes (placenta), abortion, uterine prolapse (caruncles visible)

• rectal palpation / US

  • confirm fetal viability

  • locate bladder

vaginal / cervical prolapse treatment

• decision to treat should be based on:

  • humane considerations

  • future intended use of the cow

  • prognosis

• objective: replace and retain vagina & cervix within pelvic canal + deliver live offspring

• epidural

• clean, replace, and retain the prolapsed tissue

prepubic tendon / abdominal muscle rupture etiology

• usually traumatic and related to abdominal overload (twins, hydrops, GI distention)

• rare in cattle

• last trimester

prepubic tendon / abdominal muscle rupture diagnosis & treatment

• signs/diagnosis

  • initially edema, progressing to rupture of body wall with gross distention; udder falls

• treatment

  • supportive therapy

  • induce & assist

  • C-section

  • euthanasia

prolonged gestation signs & treatment

• signs: often no udder development, failure to calve, often gradual increase in abdominal size as gestation drags on

• treatment

  • cull

  • induction of labor for valuable animals

    • prepare for dystocia