parturition

Question 1

dogs and cats have what kind of placenta

Answer 1

zonary

Question 2

zonary placenta

Answer 2

between the placenta and the allantochorion a natural accumulation of blood develops. This blood turns dark green in the dog and brown in the car

this is referred to as the marginal haemotoma

Question 3

pregnancy detection

Answer 3

conceptuses can be imaged with ultasound from day 12, but easiest around 3-4 weeks

abdominal palpation 2-5 weeks

relaxin assay - from 4 weeks, hormone released from placenta

day 45 clinical exam by MRVCS recommended

Question 4

pregnancy diagnosis who can diagnose?

Answer 4

vet only

Question 5

feline and canine pregnancy diagnosis

Answer 5

auscultation

possible to detect foetal heart beats in latter stages. HR’s of less than 150bpm can mean foetal distress and warrants investigation

Question 6

stages of parturition

Answer 6

1. first stage (onset contractions)
2. Second stage (propulsion of foetus)
3. Third stage (passage of placenta)

Question 7

Parturition aetiology

Answer 7

precise aetiology of parturition not known but generally believed that foetal distress is the initial cause

the release of foetal glucocorticoids

stimulates the release of pgf2alpha from placenta

this initiates corpora lutea regression leads to decline in progesterone - causing a sudden drop in temp

-

Question 8

preparation stage

Answer 8

in last week of pregnancy its recommended to record the dam’s rectal temp at least twice daily

this is to detect the prepartum hypothermia that precedes the onset of parturition by 24-36hours

canine behaviour - nestling, restlnessness,

feline behaviour - most seek seclusion during this stage

Question 9

first stage parturition

Answer 9

initial weak contractions that orientate cervix

cervix starts to dilate

relaxin

lasts 1-12hours

bitches become restless

cats seek seclusion

Question 10

second stage of parturition

Answer 10

foetal birth

once first foetus has entered the pelvic canal, the ferguson relfex is initiated triggering the release of a hormone that causes contractions

oxytocin - which strengthens the uterine contractions and causes the propulsion of the foetus through the cervix into the vagina

Question 11

second stage of parturition

Answer 11

during this time allantochorion membrane is usually ruptured causing a clear vulval discharge

commonly 10-30 minutes sometimes longer in primiparous bitches (fist time mothers)

Question 12

second stage parturition

Answer 12

a membrane, the amnion, surrounds the foetus

the dam will usually remove this membrane and eat the placenta. bitch should be discouraged from eating this

if the dam fails to remove membranes immediately after birth, it must be done for her swiftly

Question 13

second stage

Answer 13

puppies should be checked for

breathing
airways clear
cleft palate
anus/genitalia present
weight
sex recorded
distinguishing markings

Question 14

Third stage parturition

Answer 14

the birth of the foetus is usually followed by the passage of the allantochorion and placenta

after a bitch has finished whelping, there is normally a dark coloured vulval discharge

contains green pigment that originates from marginal haematoma

in cats the discharge should normally decline after a week

Question 15

Dystocia

Answer 15

dystocia - difficulty giving birth

rare in the queen but not in brachycephalic dogs

two main causes of dystocia - maternal factors and foetal factors

Question 16

maternal dystocia

Answer 16

inertia may be primary, in which case parturition does not commence, or may be secondary to some factor occuring during parturition

Question 16

Maternal dystocia

Answer 16

divided into 2 categories

1. insufficient straining
2. obstruction of the birth canal

insufficient straining
most commonly the result of poor myometrial contractions, a condition that has been termed uterine inertia

Question 17

Primary uterine inerta

Answer 17

rare in a cat

often seen with first time mums with small litters

or in older overweight bitches with large litters

Question 18

foetal dystocia

Answer 18

foetal size

foetal presentation

Question 19

maternal dystocia

Answer 19

hypocalcaemic causes may respond to the slow IV administration of calcium gluconate. Check HR as give ideally with ECG attached

the administration of the hormone oxytocin can be given as long as there is no obstructions to the birth canal

Question 20

Maternal dystocia

Answer 20

Secondary uterine inertia

• the cessation of uterine contractions after they have started
• often following obstructive dystocia

obstruction of the birth canal
- may be result of abnormalities of the birth canal, such as skeletal or soft tissue deformities

Question 21

Foetal Dystocia

Answer 21

Foetal size

1. breed conformation
2. actual foetal oversize- when the litter size is small or large foetuses develop within the uterus
3. foetal abnormalities - such as anasarca pictured above. Foetal monsters

Question 22

Foetal Dystocia

Answer 22

Abnormalities of foetal alignment

• variation from the normal presentation, position and posture of the foetus during delivery may result in dystocia

this may be corrected in certain cases by vaginal manipulation between contractions

Question 23

Recognition of Dystocia

Answer 23

• straining for more than 1hr
• if allantochorion ruptured and no sign of puppy/kitten

-if contractions are strong but infrequent

• decline in temp but parturition hasn’t commenced in 24 hours

any purulent discharge