73. High Risk Pregnancy in Mare

Question 1

Placentitis - Cause:

Answer 1

Middle aged multiparous mares
Ascending infection
Bacterial:
- Streptococcus equi. Zooepidemicus,
- E. coli,
- Klebsiella pneumoniae
- Pseudomonas aeruginosa

Question 2

Placentitis - Clinical Signs

Answer 2

Premature mammary gland development & lactation
Vaginal discharge

Question 3

Placentitis - Consequences:

Answer 3

Abortion
Still birth
Prematurity
Dysmaturity
Neonatal sepsis

Question 4

Placentitis - Blood Hormone Analysis:

Answer 4

Progestogens:
- Decreasing or low progestin conc in
last month
- Premature rise = foetal stress
- Acute Placentitis = rapid drop
- Chronic Placentitis = increased levels

Oestrogens
- Sharp oestrone sulphate decrease = compromised foetus
- 17 B-oestradiol sulphate decreases = placentitis

Question 5

Placentitis - Ultrasound

Answer 5

Transrectal:
- Assess chorioallantois at cervical pole
- Higher frequency probe
- Measure Combined Thickness of
Uterus and Placenta (CTUP)

Trans-abdominal:
- Measure CTUP – at cervical star
- Assess foetus in late gestation
- Assess quality and quantity of
allantoic and amniotic fluid

Question 6

Placentitis - Foetal Wellbeing

Answer 6

Foetal HR:
- Telemetric ECG
- 15-40bpm for 30s after activity

Signs of Compromise/ Stress:
* Reduced frequency of accelerations
* Increased frequency/duration of
decelerations
* Persistent bradycardia (<60 bpm)
* Persistent tachycardia (> 100bpm)

Question 7

Placentitis - Treatment

Answer 7

Treat Infection:
- 1st = TMPS
- 2nd = combined Gentamicin and
procaine benzylpenicillin

Control Inflammation – NSAIDs:
- Flunixin meglumine
- Phenylbutazone
- Firocoxib

Prevent Early Delivery:
- Promote uterine quiescence
* Synthetic progestogens
* Altrenogest
- Maintain uteroplacental perfusion
* Pentoxifylline OR aspirin

Question 8

Colicky Mare = Uterine Torsion
Clinical Signs

Answer 8

• Mid – late gestation
• Low grade, intermittent colic
• Severe colic w GI involved

Question 9

Colicky Mare = Uterine Torsion
Diagnosis

Answer 9

Speculum exam – assess cervical dilation.

Rectal palp of broad ligaments = diagnostic

Transabdo US - assess foetal viability.

US guided abdominocentesis - large vol free fluid = uterine rupture.

Question 10

Colicky Mare = Uterine Torsion
Treatment:

Answer 10

1. Roll anaesthetised mare can correct
   torsion.
   - Caution if near term = uterine rupture.
2. Surgical correction
   - Standing flank
   - Midline laparotomy
3. Transcervical manipulation in
   parturition.

Question 11

Colicky Mare - Uterine Rupture
Causes:

Answer 11

• Hydrops
• Uterine torsion
• Trauma from foetus
• Dystocia

Question 12

Colicky Mare - Uterine Rupture
Signs

Answer 12

• Colic
• Peritonitis

Question 13

Colicky Mare - Uterine Rupture
Treatment

Answer 13

• Surgical correction
• Aggressive therapy for peritonitis

Question 14

Premature Mammary Gland Development – Premature Placental Separation:

Answer 14

• EMERGENCY
• Red bag delivery
• O2 deprived as chorioallantois fails to
  rupture at cervical star & chorion
  dehiscence from endometrium
• INTERVENE – rupture membranes &
  deliver

Question 15

Premature Mammary Gland Development – Impending Abortion:
Infectious Causes:

Answer 15

• Bacterial = Ascending Placentitis
• Viral = EHV1, EHV4, EVA, EIA
• Fungal/ parasitic

Question 16

Premature Mammary Gland Development – Impending Abortion:
Non-Infectious Causes:

Answer 16

• Foetal appendices abnormalities
  * Umbilical cord, placenta
• Gestation abnormalities
  * Twinning, uterine body pregnancy
• Maternal
  
  • Nutrition, trauma, stress
• Foetal
  
  • Malformed, genetic

Question 17

Vaginal Varicose Veins:

Answer 17

**MC cause of bloody vaginal discharge
Ddx = Placentitis/ impending abortion

Diagnosis:
o Speculum exam
o Dilated veins on dorsal vaginal wall

Tx:
o Minimal bleeding = no tx
o Large vol & frequent = laser cautery/
topical tx

Question 18

Acute Abdominal Enlargement –
Prepubic tendon rupture:
Clinical Signs:

Answer 18

• Pelvic tilt
• Elevated tail head
• Lordosis/ rocking horse stance
• Udder shifts cranially
• Blood-stained secretions

Question 19

Acute Abdominal Enlargement –
Prepubic tendon rupture:
Diagnosis:

Answer 19

Ultrasound

Question 20

Acute Abdominal Enlargement –
Prepubic tendon rupture:
Considerations:

Answer 20

1. Terminate pregnancy
   * Sacrifice foal for mare’s welfare
2. Maintain pregnancy
   * Manage mare’s comfort levels +/-
   valuable foal

Question 21

Acute Abdominal Enlargement –
Prepubic tendon rupture:
Treatment

Answer 21

Restrict mare to a large stable
Abdominal support
NSAIDs
Reducing bulk of ration/laxative
Monitor foetal viability and milk electrolytes when close to term
Assisted parturition or Caesarean
?Repair afterwards

Question 22

Acute Abdominal Enlargement –
Prepubic tendon rupture:
Prognosis

Answer 22

V Poor
Euthenasia

Question 23

Acute Abdominal Enlargement – Hydrops:
What:

Answer 23

Excessive accumulation of fluid in allantoic (hydrallontois) or amniotic (hydroamnios) compartment
Last trimester
Multiparous mares
Foetal abnormalities

Question 24

Acute Abdominal Enlargement – Hydrops:
Clinical Signs:

Answer 24

Sudden change in abdominal size & shape.
Anorexia, depression, progressive lethargy.
Difficulty walking, ventral pitting oedema and dyspnoea.
-> uterine rupture or herniation

Question 25

Acute Abdominal Enlargement – Hydrops: Diagnosis:

Answer 25

Grossly enlarged uterus per rectum Generally can’t palpate foetus due to vol of fluid. US to confirm, rule out twins and assess foetal viability.

Question 26

Acute Abdominal Enlargement – Hydrops: Tx:

Answer 26

Highly unlikely to deliver a live foal at term. Terminate pregnancy to save the mare and prevent prepubic tendon rupture. Slow and gradual removal of foetal fluids = mare’s vascular system respond to changes in abdo pressure. Common sequelae: Dystocia and /or RFM