The peripartum mare: placentitis and uterine torsion

Question 1

How do you define the peripartum period?

Answer 1

Late pregnancy…early postpartum.

From about 280 days of pregnancy…. to 21 days postpartum.

Red box: days 320-380 depict fetal viability.

Question 2

Prepartum problems (5)

Answer 2

▪ Placentitis
▪ Uterine torsion
▪ Hemorrhage
▪ Abdominal wall defects

Colic is also always a possibility!

Question 3

Postpartum problems (4)

Answer 3

▪ Retained fetal membranes
▪ Hemorrhage
▪ Uterine/Rectal prolapse

Colic is also always a possibility!

Question 4

Placentitis is

Answer 4

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

Question 5

4 types of placentitis:

Answer 5

ascending placentitis
focal mucoid placentitis

diffuse plcentitis
multifocal placentitis

Question 6

Describe Ascending placentitis.

Answer 6

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

Question 7

Describe Focal mucoid placentitis.

Answer 7

Also called “nocardioform”, is uncommon but serious.

Caused by Gram+ branching filamentous actinomycetes, Crossiella equi, or Amycolatopsis spp.

Question 8

Describe diffuse placentitis.

Answer 8

Hematogenous origin such as Leptospira spp, Mycoplasma spp.

Question 9

Describe Multifocal placentitis.

Answer 9

Some fungi and bacteria cause this but its very rare.

Believed to be a chronic infection which activates in the late pregnancy.

Question 10

Pathophysiology: Ascending placentitis

Answer 10

Question 11

Answer 11

Ascending placentitis

Thickened, purlent exudate around the cervical star.

Image is of placenta.

Question 12

4 risk factors for development of placentitis:

Answer 12

• Poor perineal conformation
• Abnormalities in cervical mucous plug
• Lower urinary tract disorders
• History of vaginal/cervical examination
  in late pregnancy (iatrogenic entry of bacteria)

Question 13

Clinical signs of placentitis. (6)

Answer 13

• Premature udder developement
• Premature lactation (and thus loss of colostrum)
• Vulvar discharge in Tail hair, perineal region
• Ventral edema
• Softening of the cervix
• Abortion

Question 14

What does diagnosis of placentitis involve? (5)

Answer 14

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

Question 15

Transrectal U/S for placentitis diagnosis.

Answer 15

• 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

Question 16

Normal transrectal U/S of placenta.

Answer 16

Abnormal transrectal U/S of placenta.

Question 17

Transabdominal U/S for placentitis diagnosis.

Answer 17

• 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

Question 18

Transabdominal U/S for assessment of fetal viability and health.

Answer 18

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.

Question 19

Inflammatory markers, hematology in placentitis.

Answer 19

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

Question 20

Describe Hormonal assays like Progestins for diagnosis of placentitis.

Answer 20

• 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.

Question 21

Describe measurement of Mammary Secretion Electrolytes.

Answer 21

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.

Question 22

Treatment of placentitis, main points. (3)

Answer 22

• 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.

Question 23

Broad spectrum antimicrobials for placentitis.

Answer 23

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

Question 24

Anti-inflammatories for placentitis. (5)

Answer 24

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

Question 25

Anti-prostaglandins for placentitis.

Answer 25

Progestins * Altrenogest 0,088mg/kg, PO, q 24h Synthetic progesterone analogue, has anti-prostaglandin effect.

Question 26

Pregnancy management when placentitis.

Answer 26

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.

Question 27

Post-foaling mare and foal problems after placentitis. (3)

Answer 27

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.

Question 28

Post-foaling how should you process the placenta? (3)

Answer 28

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

Question 29

Etiology, pathophysiology of uterine torsion in the mare.

Answer 29

* 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

Question 30

Clinical signs of uterine torsion in the mare.

Answer 30

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

Question 31

Diagnosis of uterine torsion in the mare.

Answer 31

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! ## Footnote Torsion generally cranial to the cervix so vaginal examination is unrewarding.

Question 32

Transabdominal U/S for uterine torsion.

Answer 32

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.

Question 33

Tx of uterine torsion in the mare. (3)

Answer 33

1. Rolling the mare under general anesthesia. This in early 3rd trimester otherwise fetus too big to untorse. 2. Standing flank laparotomy 3. Ventral midline laparotomy

Question 34

Rolling the mare under general anesthesia.

Answer 34

* 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

Question 35

Standing flank laparotomy for uterine torsion.

Answer 35

* 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

Question 36

Ventral midline laparotomy for uterine torsion.

Answer 36

Indications * Uterine tear * Uterine rupture * Gastrointestinal involvement * Mares close to term Done in general anesthesia.

Question 37

Aftercare after uterine torsion.

Answer 37

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

Question 38

Complications of uterine torsion. (5)

Answer 38

* Uterine rupture * Uterine tears * Peritonitis * Uterine artery rupture * Abortion in 30-40% cases

Question 39

Prognosis for mares and foals after uterine torsion.

Answer 39

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