ET: Placental Exam, Parturition and abortion Flashcards
Equine dystocia
Not due to fetal: maternal disproportion
Caused by postural abnormalities
Red bag
Premature placental separation
Emergency, requires immediate action
Foaling problems of fetal origin
Twinning
Developmental anomalies
Wry neck/ wry nose (can remodel after birth)
Dystocia
Uterine torsion
Evident @ 6-8 months and with discomfort of the dam
Discomfort secondary to vascular compromise of fetus
Tx of uterine torsion
Flank sx to resolve
Prepubic tendon rupture
Secondary to sever ventral edema
Rupture of the middle uterine artery
Happens post-foaling within a week
Results in a rapid demise of the mar e
Secondary to uterine prolapse
Perineal lacerations
Results of dystocia
First (anal sphincter and perineal body intact), second (fistula of perineal body) and third degree
Third degree perineal lacerations
Acute bruising (sx repair will fail)
Thirty days later: freshen and debride, then do repair
Gestation length
10.5 to 13 months (ave 11- 11.5 months)
Abortion
Expulsion from the uterus of a living fetus before it’s capable to independent life or a dead fetus recognizable size at any age of gestation
Fresh fetal death
Died in utero < 24 before delivery
EHV-1
Autolytic fetal death
Died in utero 24-48 hours before being delivered
EVA (viral), bacterial (strept) and fungal/ mycotic
A fetus may also be aborted __________ but nonviable from ____________-
- alive
- late term EHV-1 abortion
Determining fetal time of death
6-12 hrs: corneas cloudy and gray
12-18 hrs: emphysematous degeneration
24 hrs: Kidneys soft
36 hrs: skin discoloration, subcutis, gelatinous liver soft
Fetus is more often autolytic subsequent to ___________ in utero conditions
chronic
Thickened placenta
Reduces the fetus’s nutrition and slow removal of its waste products → intrauterine growth retardation (IUGR)
Twinning
Most common non-infectious cause of equine abortion
Insufficient placentation is the reason of loss of twin pregnancies
Transvaginal ultrasound-guided twin reduction
By embryonic to fetal stabbing
Yolk sac or allantoic fluid aspiration
Early reduction preferred
>35 days
Twin reduction: 55-150 days gestation
Cranio-cervical dislocation- first cervical vertebrae from the cranium, serving the SC and disrupting the ligamentous attachments
Late gestation dx of twins
Majority begin between 7-8 months gestation
Premature mammary development
Essential samples for abortion dx
Fetus, placenta and maternal blood
Bacterial abortions
Most commonly an ascending infection
Inflammatory response that impairs the placenta’s ability to sustain the pregnancy
Overwhelmed placenta = terminated pregnancy
B- hemolytic streptococci
Sporadic abortion @ any stage
Associated with dirty environment
Fetal autolysis
E. coli
Second most common bacterial cause of abortion
> 6 months when fecal contamination is overwhelming
Leptospirosis (bacterial abortion)
Zoonotic disease, most subclinical
Cause diffuse placentitis
CS: jaundice, recurrent uveitis, fever, Hbunira
Nocardiofrom actinomycete
G+ branching actinomycete
Mucoid exudate
Placental thickness and exudate ID by ultrasound
Equine fungal/mycotic abortions
Primarily ascending infections
5th-11th month of gestation
Severe, chronic placental changes
Edema, thickening skin (alligator) and necrosis,
Chronic placentitis (thickening) leads to…
↓ fetal nutrition
Intrauterine growth retardation
Small fetus for its gestational age
What causes fungal uterine infections in barren mares?
Excessive abx use
Mycotic abortion
Submit fetal skin or stomach contents and placenta (fresh and in formalin)
Viral abortion
From equine rhinopneumonitis (EHV-1), equine viral arteritis (EVA), and arterivirus (RNA)
Another cause of viral abortions
Contagious equine metritis from taylorella equigenitalis (CEM)
EHV-1 rhinopneumonitis
Most common
Incubation: 8 days-4 months
Abort in latter pregnancy
Abortion storm with unvx herd (>90%)
EHV-1 aborting mare
No premonitory signs
Spontaneous abortion
Fetus, placenta and uterine secretion all infective
EHV-1 Prevention
Vx of non-preg animals (6 m immunity)
Vx of pregnant animals @ 3,5,7, 9 m gestation
Vx immunity ↓ by 8 weeks post vx
Key dx for EHV-1
Fetus (fresh)
Mild fetal icterus
Hydrothorax/ hydroperitoneum
1-2 mm grey/ necrotic foci in liver (with eosinophilic IBs)
Equine viral arteritis (EVA)
Dam sick before she aborts
Abortion during or immediately after acute maternal infection (incubation 6-10 days)
Placental/ fetal autolysis
Between 5th-10th m gestation
Dx of EVA
Paired titers of affected mares/ stallion
Confirm shedding by stallion
Contagious Equine Metritis (CEM)
Reportable
Poor breeding efficacy, early abortion of mares, vaginal discharge
Veneral transmission
Trypanosoma equiperdum (Dourine)
Sexual contact transmission
Acute: silver dollar plaques on skin
Chronic: emaciation, paresis, intermittent fever and death
Babesia equi and B. caballi (prioplasmosis)
FL
Spread by blood-sucking ticks
Dx by ID organism in RBCs
Overo lethal white syndrome
Paint horses
Always fatal, both parents contribute
Full- term foals, normal gestation, all white with blue eyes → few hours after birth= colic
