Canine: Pregnancy + Parturition

Question 1

What is the duration of a canine pregnancy?

Answer 1

Actual duration = from ovulation to parturition = 60-63 days

Apparent duration = from mating to parturition = 58 - 72 days

note: dogs could mate together, the male could ejaculate and the sperm could remain in the female tract for many days before she ovulates and becomes pregnant

Question 2

How can you tell if a dog is actually pregnant or is going through a pseudopregnancy?

Answer 2

• Day 21: radiograph, see uterine enlargement only
• Day 25-30: abdominal palpation, might feel bulges in the uterus
• Day 28: U/S, looking for heartbeats
• Day 35: U/S looking for fetal movements and take fetal measurements
• Day 45+: radiograph, ossification of fetal bones

Note: should also be taking into consideration, weight gain, abdominal enlargement, and mammary gland development of the bitch

Question 3

On what day of pregnancy can you confirm a viable (living fetuses) pregnancy and calculate when the dam will whelp?

Answer 3

Day 35: with ultrasound, will see heartbeats and can take fetal measurements to confirm when she may whelp

Question 4

What is a pseudopregnancy and why does it happen?

Answer 4

A normal phenomenon in all bitches

It is caused by a decline in systemic progesterone, which leads to increased concentrations of prolactin

Question 5

An owner complains that her breeding bitch is aggressive to family members, they know this can be a sign of pseudopregnancy but what can be done?

Answer 5

1) Rule out a true pregnancy
2) Let the owner know this will pass within a few weeks

3) If absolutely necessary then one of the following can be done:
- Sedation
- Treat with antiprolactins: serotonin antagonists (nervousness is a side effect thus may not be suitable) or dopamine agonists
- Treat with progestagens

Question 6

A breeder is waiting for her dog to whelp, what can she look out for in the days leading up to her due date?

Answer 6

• Changes in behavior 24 hours before whelping

- Drop-in temperature 12 hours before whelping

Question 7

What occurs in the first stage of parturition in the dog?

Answer 7

• Uterine contractions with increased frequency and intensity
• Cervix and vagina relaxes
• Most caudal fetus will rotate along its long axis and extend its head, neck and limbs
• Fetus is pushed into the cervix which dilates

Question 8

A pregnant dog is restless, keeps looking at its abdomen, panting, shivering, shredding paper, and has vomited, which stage of parturition is she likely in?

Answer 8

1st stage

Question 9

How long can the first stage of parturition last in the dog?

Answer 9

6 - 12 hours

Question 10

What occurs in the second stage of parturition in the dog?

Answer 10

• Expulsion of 1st fetus
• Allantochorion ruptures in the birth canal
• Amnion + umbilical cord is bitten by dam then she licks her pup

Question 11

How long can it take between pups to be born during whelping?

Answer 11

5mins to 3 hours

Question 12

A pregnant dam has abdominal straining, a temperature rise, fluid is appearing at her vulva, which stage is she likely in?

Answer 12

2nd stage

Question 13

What happens in the third stage of parturition?

Answer 13

• Expulsion of fetal membranes: usually passed within 15 mins of the pup being born
• uterine involution: pups are usually delivered on alternate horns, the horns shorten with delivery of each pup

note: complete involution will take 12-15 weeks

Question 14

A dog has whelped her litter and has been having mucus discharge from her vulva for the past week, is this a concern?

Answer 14

No, this vaginal discharge is called lochia, it will contain blood, mucus and uterine tissue
She will continue to produce this discharge for 3-6 weeks after whelping

Question 15

A whelping dog has a green discharge coming from her vulva before the 1st pup has been delivered, is this a concern?

Answer 15

No, this is lochia/ uterverdin, it indicates placental separation
The green colour does NOT mean bad!

Only if a pup has not been delivered 2 hours after passing that lochia is it a concern, this means dystocia

Question 16

How often does dystocia occur in the dog?

Answer 16

5%

Very low!

Question 17

What are the 3 main causes of dystocia in dogs?

Answer 17

• Uterine inertia (72%)
• Fetal malpresentation (15%)
• Fetal oversize/ monsters (8.2%)

Question 18

A dog presents with dystocia, what are the steps to approaching this case?

Answer 18

1) History + general exam: stage of labour? lochia passed?
2) Vaginal exam: any obstructions? fetal fluids? can you feel a fetus?
3) U/S or x-ray: any pelvic defects? fetal orientation? is the pup alive?

Question 19

A pregnant dog presents with green vulval discharge but no fetus, fetal fluids but no straining, no signs of labour for more than 2 hours, non-productive straining for 20-30 mins
What is this indicative of?

Answer 19

Dystocia

Question 20

You do an xray on a pregnant dog, you notice there is a lot of air (physometra) around the pups in the uterus, what does this indicate?

Answer 20

Fetal Dystocia

Question 21

What is the difference between complete and partial uterine inertia?

note: these are both primary causes

Answer 21

Complete uterine Inertia: the uterus doesnt contract at all leading to failure of stage 2 of parturition

Partial uterine Inertia: the uterus contracts but not enough to deliver all puppies

Question 22

You diagnose a pregnant bitch with primary uterine inertia, why might this be happening?

Answer 22

• litter is too small
• litter is too big: leading to overstretched myometrium
• genetic/ inheritance
• systemic disease
• nutritional deficiency

Question 23

What is the most common cause of maternal dystocia in dogs?

Answer 23

Uterine Inertia

Primary vs Secondary

Question 24

What is secondary uterine inertia?

Answer 24

The exhaustion of uterine musculature after contracting against an obstruction

Question 25

You suspect a pregnant dog to have uterine inertia, what can you do to help?

Answer 25

• Determine if the bitch is in labour
• Rule out any obstructions
• Exercise the dam
• Vaginal examination
• Mild sedation + quiet environment
• Oxytocin: 2.5-10 IU IM or 1-5 IU IV
• +/- Calcium: 2-20ml of 10% solution IV
• C-section

Question 26

A breeding bitch has been having difficulty getting pregnant, what are some causes for this?

Answer 26

• Inappropriate mating time
• Infertile male
• Anovulation due to:
  Prolonged pro-estrus, which never ends up in an estrus
  Progesterone rises, then drops, instead of being maintained

Question 27

A dog has been accidentally bred and the owners want to terminate the pregnancy, what can be done?

Answer 27

1) Ovariohysterectomy

2) Administration of Estradiol benzoate (Mesalin)
This will prevent embryo transport into the uterine tubes, will alter the endometrium and prevents implantation, and has a degenerative effect on the ova
Dose:
- High dose: 5-10mg once within 4 days of mating
- Low dose: 0.01mg/kg on days 3 and 5 post mating

CAUTION: using estradiol benzoate can lead to pyometra and thus a OVH may need to happen

3) Administration of Antiprogestins (Aglepristone)
Dose:
- 10 mg/kg, 2 injections given 24 hours apart
Good efficacy + safety with no increased risk of pyometra
Note: abortion can be done up to 45 days

4) Administration of Prostaglandins (this is the go to drug for other species, but it is NOT licensed for use in small animals!)
CAUTION: lots of side effects in small animals

5) Prolactin Antagonists (dopamine agonists)
These will inhibit prolactin secretion which is essential for CL maintenance
Dose:
- 5ug/kg given intra-osseous once a day for 5 days

Question 28

You palpate a retained fetus or placenta in a dog, this is confirmed with U/S, what is the treatment for this?

Answer 28

• Oxytocin TID

- Antibiotics

Question 29

You notice a dog is not producing milk (agalactia) after her parturition, what is the treatment for this?

Answer 29

• Establish the cause for the agalactia: nervousness, systemic illness
• Oxytocin

Question 30

You notice a dog is not feeding her pups and suspect mastitis, what is the treatment for this?

Answer 30

• Antibiotics
• Analgesia
• Cold cabbage wrap

Question 31

What is Eclampsia/ Pre-eclampsia?

Answer 31

Eclampsia is a condition in lactating dogs that leads to weakness, muscle stiffness, seizures, and even death. It is caused by low levels of CALCIUM in the blood. In dogs, eclampsia is also called puerperal tetany, puerperal hypocalcemia, postpartum hypocalcemia, or periparturient hypocalcemia

note: in humans, eclampsia is due to high blood pressure

Question 32

What is the treatment of eclampsia in dogs?

Answer 32

• Calcium borogluconate IV

- Oral supplementation with calcium carbonate + Vitamin D

Question 33

You notice a dog is not tending to her puppies, what can be done to entice her?

Answer 33

• Could be due to post C-section, give it some time to wake up
• Pain associated: provide pain control
• Environment is unsuitable: reduce noise, provide warmth and nest-box
• Improved newborn acceptance and prevention of newborn rejection when puppies are bathed in amniotic fluid before being presented to the dam

Question 34

You are told a post-partum bitch has been having a sanguineous discharge coming from her vulva, is this normal?

Answer 34

Yes this sanguineous discharge is normal, it usually lasts 4-6 weeks but can last up to 16 weeks. Usually resolves spontaneously
Due to subinvolution of the placental sites
Future breeding prognosis is good

Question 35

What is the best way to detect estrus in a dog?

Answer 35

Plasma Hormone measurements of progesterone and vaginal cytology

note: this can be difficult as you will usually have to take a blood sample every second day for 1-2 weeks
- Progesterone begins to increase in late proestrus