The peripartum mare: placentitis and uterine torsion Flashcards
How do you define the peripartum period?
Late pregnancy…early postpartum.
From about 280 days of pregnancy…. to 21 days postpartum.
Red box: days 320-380 depict fetal viability.
Prepartum problems (5)
▪ Placentitis
▪ Uterine torsion
▪ Hemorrhage
▪ Abdominal wall defects
Colic is also always a possibility!
Postpartum problems (4)
▪ Retained fetal membranes
▪ Hemorrhage
▪ Uterine/Rectal prolapse
Colic is also always a possibility!
Placentitis is
Inflammation of placenta (chorioallantois).
Common cause of late term abortions and premature delivery. 1/3 of abortion cases have placentitis involved.
Affects interchange of
▪ Gases
▪ Nutrients
▪ Waste products
Will be an Individual mare problem
▪ Sporadic
▪ Doesn’t affect fertility
4 types of placentitis:
ascending placentitis
focal mucoid placentitis
diffuse plcentitis
multifocal placentitis
Describe Ascending placentitis.
THE MOST COMMON TYPE of placentitis
Bacterial, most common pathogens:
* Streptococcus equi zooepidemicus,
* E. coli,
* Enterobacter agglomerans,
* Klebsiella spp,
* Pseudomonas spp,
* Staphylococcus aureus
Or even fungal:
* Aspergillus spp, Candida spp
Describe Focal mucoid placentitis.
Also called “nocardioform”, is uncommon but serious.
Caused by Gram+ branching filamentous actinomycetes, Crossiella equi, or Amycolatopsis spp.
Describe diffuse placentitis.
Hematogenous origin such as Leptospira spp, Mycoplasma spp.
Describe Multifocal placentitis.
Some fungi and bacteria cause this but its very rare.
Believed to be a chronic infection which activates in the late pregnancy.
Pathophysiology: Ascending placentitis
Ascending placentitis
Thickened, purlent exudate around the cervical star.
Image is of placenta.
4 risk factors for development of placentitis:
- Poor perineal conformation
- Abnormalities in cervical mucous plug
- Lower urinary tract disorders
- History of vaginal/cervical examination
in late pregnancy (iatrogenic entry of bacteria)
Clinical signs of placentitis. (6)
- Premature udder developement
- Premature lactation (and thus loss of colostrum)
- Vulvar discharge in Tail hair, perineal region
- Ventral edema
- Softening of the cervix
- Abortion
What does diagnosis of placentitis involve? (5)
U/S
* transrectal (more common) or transabdominal
Clinical exam
* Cervix assessment with a Sterile speculum and carries a risk of stimulating the cervix.
Inflammatory markers, Hematology
* SAA, Fibrinogen, WBC
Hormonal assays
* non specific
Electrolytes in milk
* non specific
Transrectal U/S for placentitis diagnosis.
- 5MHz rectal probe
Measure Combined thickness of the uterus and
placenta (CTUP)
* Cervical star region, 2,5 cm from the cervix
* Ventral aspect of uterine body, 3 measurements
* Increased values, compare to Normal values for combined thickness of the uterus and placenta.
Accumulation of purulent material between
chorioallantois and endometrium may be seen on U/S.
CTUP = combined thickness of the uterus & placenta
Normal transrectal U/S of placenta.
Abnormal transrectal U/S of placenta.
Transabdominal U/S for placentitis diagnosis.
- 3 or 5 MHz sector probe
Hematogenously-induced or nocardia-form placentitis
* Assess Placental membrane integrity and thickness. Assess for separation.
* Assess Fetal fluid character. Assess for purulent material (hyperechoic).
- You Can’t evaluate cervical star region from abdo U/S.
Check 4 regions transabdominally:
* right cranial, right caudal
* left cranial, left caudal
- Min CTUP of 7.1 ± 1.6 mm and max 11.5 ± 2.4 mm
- Increased CTUP = delivery of abnormal foal
CTUP = combined thickness of the uterus & placenta
Transabdominal U/S for assessment of fetal viability and health.
Fetal HR
* > 300d gestation 75±7 beats/min
* > 330d 65 beats/min
Fetal stress
* Bardycardia <55b/min
* Really sick if Tachycardia 120b/min
Body tone
* Excellent tone would be Active and Flexes and extends torso, neck, limbs.
* Atonic would be Flaccid, Lies passively.
Diameter of fetal orbita can be measured to assess gestational age and fetal growth.
Inflammatory markers, hematology in placentitis.
All increased in placentitis.
- Serum amyloid A also sees a Normal increase in mares 36h before delivery, earlier is possible too.
- Fibrinogen up
- WBC up
Describe Hormonal assays like Progestins for diagnosis of placentitis.
- Synthesized by the fetoplacental unit at >150d gestation, supports pregnancy.
- Concentration stable in second half of pregnancy so an increase can indicate Placental pathology or Fetal stress.
- Before parturition (>315d) progestin concentration rises significally only to fall dramatically 24-48h before delivery.
- Commercial specific assays not available.
- Radioimmunoassays, ELISA in lab using Plasma progestins, non-specific though. Cross-reactions possible.
Describe measurement of Mammary Secretion Electrolytes.
Serum chemistry analyzers can be used (after dilution).
* Serial samples better
Early changes in calcium, potassium and sodium concentrations.
Parturition usually sees:
* Calcium increase at 24-48h ≥40mg/dl.
* Sodium decrease, 3-5 days prior.
* Potassium increase, 3-5 days prior.
Stall side tests for Ca and Mg.
Treatment of placentitis, main points. (3)
- Goal is to reduce inflammation and control myometrial activity.
- Combination of antimicrobials, anti-inflammatories and tocolytics (to decrease myometrial contractions).
- Treat at minimum until delivery or at least 320d preganancy.
Broad spectrum antimicrobials for placentitis.
Trimetoprim sulfa (TMS) 30 mg/kg, PO, BID
Penicillin + gentamycin
* Potassium penicillin G 22000 IU/kg, IV, q 6h or
Procaine penicillin G 22000 IU/kg, IM, q 12h
* Gentamicin 6,6mg/kg, IV, q 24h
Anti-inflammatories for placentitis. (5)
Flunixin meglumine 1,1 mg/kg, IV or PO, 12-24h
Phenylbutazone 2,2-4,4 mg/kg, PO, q 12-24h
Firocoxib 0,1 mg/kg, PO, q 24h
Pentoxifylline 8,5mg/kg, PO, q 12h
* Drug that downregulates cytokines
* Increases blood flow
* Effect questionable for placentitis though.
Acetylsalicylic acid (Aspirin) 50mg/kg, PO, q 12h
Anti-prostaglandins for placentitis.
Progestins
* Altrenogest 0,088mg/kg, PO, q 24h
Synthetic progesterone analogue, has anti-prostaglandin effect.
Pregnancy management when placentitis.
Long term therapy and monitoring required, may even stay in the hospital until delivery in some cases.
Transabdominal U/S daily.
Transrectal U/S Daily.
* Assess response to therapy, is the placenta still attached. How is the foal doing.
* Move to Every second/third day when the mare and foal are stabilized. Maybe even less often depending on the case.
Post-foaling mare and foal problems after placentitis. (3)
Neonatal septicemia is possible.
* Blood culture to check for it
* Treat with antibiotics
Uterine lavage
* Removal of uterine debris and residual microbes.
* Large volume uterine lavage 2-3x with 6 to 12 L per flush.
* Use a New/sterile/disinfected nasogastric tube, Protect with gloved hand on entry.
* Funnel, rectal glove, stomach pump for Infusion and siphoning.
Give Antimicrobials and antiinflammatories for
* 5-7d
* Do Uterine culture.
Post-foaling how should you process the placenta? (3)
Check both sides (allantoic and chorionic) for:
* Areas of oedema
* Areas of hemorrhage
* Exudate
Take culture and PCR swab samples:
* Bacterial culture
* Viral PCR (EHV, Equine arteritis virus)
Take histological samples:
* Umbilical cord
* Chorioallantois
* Amnion
Etiology, pathophysiology of uterine torsion in the mare.
- Etiology Not well known. A combination of fetal activity and sudden recumbency and rolling of the mare is suspected.
- Increased elasticity of the broad ligament along with malposition of the fetus.
- Occurs in Last trimester, ≥7 months.
Is an EMERGENCY!
* Risk of Necrosis and rupture of the uterus.
* Risk of Fetal death
Clinical signs of uterine torsion in the mare.
Colic signs Depending the severity of torsion.
* ± Tachycardia, tachypnoe, pyrexia, decreased GI sounds.
Mild colic
Acute colic
* Discomfort
* Sweating
* Anorexia
* Frequent urination
* Looking at the flank
* Kicking at the abdomen and rolling
Diagnosis of uterine torsion in the mare.
Rectal palpation of the uterine broad ligaments.
* One broad ligament is stretched horizontally
across the top of the uterus and courses
ventrally and laterally across the midline.
* 180˚-540˚
Torsion to the right = clockwise
* Left broad ligament streched over the uterus
Torsion to the left = counterclockwise
* Right broad ligament stretched over the uterus
- 50:50 chance
- Not 100% accurate!
Torsion generally cranial to the cervix so vaginal examination is unrewarding.
Transabdominal U/S for uterine torsion.
You can check:
* Fetal viability
* Fetal heart rate and mobility
* Clarity of fetal fluids
* Dilation of blood vessels
* Placental edema
- Uterine damage
GI tract involvement in 50% of cases.
* Entrapment/strangulation of jejunum or small colon within uterine torsion.
* Concurrent intestinal volvulus or displacement.
Tx of uterine torsion in the mare. (3)
- Rolling the mare under general anesthesia. This in early 3rd trimester otherwise fetus too big to untorse.
- Standing flank laparotomy
- Ventral midline laparotomy
Rolling the mare under general anesthesia.
- Drop her on the side to which the torsion is directed.
- Place a board across the mare’s upper paralumbar fossa. (size 3-4m x 20-30cm)
- Roll the mare slowly
- Repeat rectal examination
Do not use it if:
* Mare close to term
* GI involvement
* Not sure about the direction of the torsion.
* In Draft mares
Standing flank laparotomy for uterine torsion.
- Sedation and local anesthetic infiltration along the injection site.
- Side depends on surgeon.
- From side toward which torsion is directed (e.g., right side for clockwise torsion): Surgeon’s hand passed ventrally, uterus lifted and rotated upwards.
- From opposite side: Surgeon’s hand passed dorsally, uterus pulled torward the surgeon.
- Sometimes incisions on both sides.
- No risks considering general anesthesia since not under GA, only infiltration.
Do not use it if:
* Crazy mare that won’t stand calmly enough.
* Uterine tear
* Mare close to term
Ventral midline laparotomy for uterine torsion.
Indications
* Uterine tear
* Uterine rupture
* Gastrointestinal involvement
* Mares close to term
Done in general anesthesia.
Aftercare after uterine torsion.
Same as for placentitis.
Progestin
* Altrenogest 0,088mg/kg, PO, q 24h
* Synthetic progesterone analogue, has anti-prostaglandin effect.
NSAIDs
* Flunixin meglumine 1,1 mg/kg, IV or PO, 12-24h
* Firocoxib 0,1 mg/kg, PO, q 24h
Broad spectrum antibiotics
* Trimetoprim sulfa (TMS) 30 mg/kg, PO, BID
Pen+genta
* Potassium penicillin G 22000 IU/kg, IV, q 6h or
Procaine penicillin G 22000 IU/kg, IM, q 12h
* Gentamicin 6,6mg/kg, IV, q 24h
Complications of uterine torsion. (5)
- Uterine rupture
- Uterine tears
- Peritonitis
- Uterine artery rupture
- Abortion in 30-40% cases
Prognosis for mares and foals after uterine torsion.
For survival ~85% mares survive
* when ≥ 320d 65%
* when < 320d 97%
* Method of correction doesn’t affect survival.
Foal ~56% survive
* when ≥ 320d 32%
* when < 320d 72%
* If <320d, foal survival higher with standing flank celiotomy vs ventral midline approach.
For future fertility: good prognosis.
Worse if:
* Cesarean section
* Uterine rupture
* Higher degree of torsion
* Delay in treatment
