Dystocia and it's treatment

Question 1

For a normal birth, the 3 stages take on average:

Answer 1

1. 6-12 hours (1-36)
2. 6-12 hours
3. 1-2 hours after expulsion of the last fetus or during stage 2.

There is an increase mortality as length of parturition increases.

The definition of dystocia is ”difficult birth” and this is often seen in the bitch and
often requires assistance.

Question 2

Maternal Causes of dystocia (7)

Answer 2

❖ Uterine inertia (primary/secondary)
❖ Anatomic defects of the pelvis

❖ Excessive perivaginal fat
❖ Vaginal strictures or vaginal septum

❖ Uterine torsion/rupture
❖ Inguinal hernia

❖ Behavioural issues such as anxiety

Question 3

fetal Causes of dystocia (3)

Answer 3

❖ Malpresentation
❖ Malposition
❖ Malposture

Question 4

Uterine Inertia Is

Answer 4

the failure of the uterus to contract effectively and is the most common maternal cause of dystocia.

Question 5

Primary inertia, which is before delivery of the first puppy, is commonly seen in (4)

Answer 5

❖ large bitches with large litters with overstretching of the muscle fibers.

❖ Small litters with inadequate endocrine stimulus.

❖ Decreased amount of oxytocin receptors in the uterus.

❖ Uterine torsion (not common in dogs) or uterine rupture (from trauma).

NB All the causes of primary inertia may also cause secondary inertia.

Question 6

Secondary inertia refers to weak contractions after delivery of at least 1 puppy and can be due to: (4)

Answer 6

❖ Hypocalcemia

❖ Hypoglycemia

❖ Fetal obstruction (with excessive uterine contractions)

❖ Delivery of most of a large litter, but where the last puppies remain unborn so exhaustion of the uterine muscles.

All the causes of primary inertia may also cause secondary inertia.

Question 7

Oversize fetus or disproportion between fetus and bitch can be described as:

Answer 7

1. Absolute: (”fetomaternal
   disproportion”) (small litters, fetal monsters)
2. Relative: (”fetopelvic disproportion” (some breeds are predisposed)

Question 8

Absolute disproportion is when

Answer 8

the fetus is abnormally large.

Also called ”fetomaternal disproportion” (small litters, fetal monsters).

Question 9

Relative disproportion is when

Answer 9

the fetus is normal but the pelvis is smaller than normal.

Also called ”fetopelvic disproportion” (some breeds are predisposed).

Question 10

The fetal disposition includes (3)

Answer 10

fetal presentation
fetal position
fetal posture

Question 11

Fetal Presentation is the

Answer 11

relationship between the longitudinal axis of the fetus, e.g. anterior/posterior, longitudinal/transverse presentation.

Question 12

Fetal Position refers to

Answer 12

which surfaces of the maternal birth canal are in contact with the fetal vertebral column e.g. dorsal/ventral position.

Question 13

Fetal Posture is

Answer 13

the disposition of limbs/head of the fetal body, e.g. flexions/extensions of different joints.

Question 14

In dogs, puppies are delivered in what positions?

Answer 14

both anterior and posterior longitudinal position with a frequency of 60:40 for anterior/posterior.

Abnormal disproportion is common in both anterior and posterior presentation and
may cause obstruction.

Transverse presentation is rare and irregularities of limb posture are not always an obstacle as long as the puppy is of normal size.

Question 15

Fetal monsters occur occasionally and can cause obstruction.

What are 2 causes of fetal monsters?

Answer 15

primarily anasarca (water-puppies) and hydrocephalus.

Dead fetuses can cause obstruction – no movement so they have not positioned themselves correctly.

Question 16

Warning signs / indications for investigation or c-section. (7)

Answer 16

 If pregnancy exceeds 65 days post-ovulation/67 days post LH-surge.

 >4 hours after rupture of the allantochorion of the first puppy

 >30 min with hard contractions without presentation of the first puppy

 >2 hours between puppies

 Increasing (over 1-2 hours) greenish/black vaginal discharge without delivery of the first puppy.

 Large amounts of bloody vaginal discharge during any part of the delivery.

 Bitches presented with acute abdominal pain or collapse or that shows no interest in the puppies.

Question 17

When the bitch presents with dystocia - do the following: (3+)

Answer 17

 Put her in a quiet room with bedding

 Heating box/incubator ready for the puppies

Equipment that has to be available
❖ Small towels
❖ Absorbable sutures for the umbilical cords
❖ Disinfectant for the umbilical
cords (iodine/chlorhexidine)
❖ Oxygen
❖ Suction bulbs for the nose/mouth of the neonates

Question 18

Dystocia, initial examination. (4)

Answer 18

Anamnesis including: date of mating, results of estrus controls, general health
issues, history of prior deliveries or dystocia, behavioral changes, full description of the delivery until now.

Health examination: temperature, pulse, respiration, CRT, auscultation of the
lungs/heart, is she exhausted?

Palpation of mammae for the presence of colostrum.

Reproductive examination including:
❖ Is there a fetus/fetal membranes presented
❖ Are there any strictures or vaginal septum
❖ Check the ”ferguson reflex”
❖ Use a rigid proctoscope to look at the cervical entrance

Question 19

U/S in dystocia.

Answer 19

❖ Amnion fluid has to be bright black and an increase in echogenicity may indicate
meconium in the fetal fluid due stress and placental separation (but normal for bulldogs).

Assess fetal viability with the U/S
* Fetal heart rate < 180 beats/min is a sign of fetal distress
* Fetal heart rate < 160 beats/min → emergency intervention
* Hypoxia depresses the heart rate and fetal heartrate consistantly
between 140-180 beats/min are indicative for fetal stress and hypoxia

Assess the Placentas:
distinct hyperechogenic line between the fetal and maternal part
of placenta (fetal part 2/3 of the maternal part after day 45) → edema may
indicate abnormalities→ hypoxia of th epuppies

Question 20

X-ray in dystocia.

Answer 20

Always both LATs and DV to view fetal positioning.

❖ Obstruction of the pelvic canal
❖ Number of puppies left
❖ Are there any puppies left at all

Measure biggest puppy skull and smallest diameter of pelvic inlet.

If indicated full blood analysis (CBC, serum chemistry, ionized calcium and urine analysis (for glucosuria, ketonuria).

Question 21

Medical therapy for dystocia is absolutely contraindicated in cases of

Answer 21

obstructive dystocia!

Risk of uterine rupture!

Question 22

Criteria to fill for medical therapy for dystocia. (6)

Answer 22

Dystocia with:

❖ The bitch is in good shape and not too tired.

❖ The delivery has not been going on for a long period of time.

❖ No obstructions

❖ Heart rate on the puppies >190 bpm

❖ Not more than 4 puppies left in the uterus

❖ A strong ferguson reflex. If the ferguson reflex is weak or non-existent, measure ionized calcium and blood glucose before giving oxytocin.

Question 23

Drug therapy options for dystocia.

Answer 23

Calcium-gluconate 10% normally 0,2 ml/kg slowly if given iv, it can be mixed with
isotonic glucose or saline and given over 20 minutes.

• Afterwards leaving the bitch for 30 min
• The calcium administration can be repeated after 6 hours if the straining decreases.

If ferguson reflex is strong→ oxytocin can be administered, otherwise can be used
after the administration of calcium/glucose:

Give oxytocin in microdosages 1-2IU/sc, im, iv → repeat every 30 minutes, up to 3
times.

If oxytocin fails to give an uterine response in contractions, a cesarean section
should be performed.

Never give the breeder oxytocin to treat at home!

Question 24

Indications for a cesarean section in dogs and cats: (5)

Answer 24

• Fetal heart rate consistently < 190 bpm
• More than 4 puppies in the uterus
• Any obstructions
• No response to conservative therapy in the case of uterine inertia.
• If the bitch is exhausted

If the puppies heart rates are low → treating the bitch with atropine will increase the heartrate of the puppies, because it passes the placenta.

Question 25

Total serum calcium in eclampsia?

ionized calcium in clinical eclampsia?

Answer 25

Total serum calcium < 7ng/ml

or ionized calcium < 1,25 ng/ml

is considered diagnostic of hypocalcemia.