1. From Pregnancy to Parturition
The Path to Puppies
From Pregnancy to Parturition
Melissa Hoernis

2. Terms
Pregnancy: The state of carrying developing embryos or fetuses in the female body
Parturition: The process of giving birth to offspring

3. Female Reproductive Tract of Dogs
Ovary: Place where the ova is made and released from
Oviduct: Connects the ovary to the uterus
Uterus: Place that holds the growing fetuses
Cervix: Acts as a barrier to keep bacteria from getting to the growing fetuses
Pelvic canal: The birth canal (the way the fetuses get to the outside world)
Suspensory ligament
Ovary
Oviduct
Uterine horn
Uterine body
Cervix
Pelvic Canal

5. Conception: formation of an embryo
An embryo is formed when the egg becomes fertilized and starts growing from one single cell into thousands then millions.

6. What about the GENES!
Genes hold the information to build and maintain an organism's cells and pass traits to offspring

7. DNA
This is what is in the nucleus of a cell and is the blueprints for the entire body
Chromosome
Gene
DNA

8. Number of Chromosomes 39 pairs = 78 total
Each cell in a dog has 39 PAIRS of chromosomes for a total of 78!
39 pairs = 78 total

9. Each gamete (egg/ sperm) has HALF the genetic information needed
39 chromosomes from the mother
39 chromosomes from the father
78 chromosomes total
So when they combine the genetic information is made complete!

10. A quick course in EMBRYOLOGY
The egg is fertilized and then starts dividing and multiplying EXPONENTIALLY

11. Then this clump of cells starts to change and form different types of tissues that then form organs then organ systems. This is called differentiation.
Cell- smallest unit
Tissue- groups of cells with same general function and texture (example: Muscle)
Organ- two or more types of tissues that combine to serve a specific function (example: Stomach)
Organ system- several organs that work together to serve a specific function (example: Digestive system)

12. Development of the embryo
What is an embryo?
An embryo is what we call the puppy from the point when the egg is fertilized until the body is fully developed (just miniature).

13. Growth of the fetus What is a fetus?
Once the embryo is fully developed it still needs time to grow while it is in the mother’s womb. The fetus is what we call the puppy once it is fully developed but still growing.

14. Guess the species of each embryo!

15. How about now?

16. OKAY… How about now?
Fish Salamander Tortoise Chicken Pig Cow Rabbit Human

17. The Placenta
The Placenta is a temporary organ formed in the uterine wall of the mother that is connected to the fetus via the umbilical cord.

18. The Placenta Purpose: Nutrients Gas exchange Waste elimination
The fetus needs food to grow
Gas exchange
The fetus cannot breath but it’s body still needs oxygen to work so the mother provides oxygen
Waste elimination

19. Gestation Length
The length of time from conception until birth

20. Let’s COMPARE
63 Days
335 Days
63 Days
625 Days
270 Days

21. Pregnancy
What are some signs that the female is pregnant? (can you guess any)
Weight gain (doesn’t start until week 4)
Increased appetite (again not until week 4 and some have decreased appetite at times)
Nesting behavior
Drop in temperature

22. Tools veterinarians use to diagnose pregnancy
Radiographs
Fetal skeletons seen by day 42
Best way to find out how many there are
Ultrasound
Beating hearts by day 25
Measurement of certain hormones

23. Parturition- the birthing process
There is a hormone cascade and feedback system!
It all starts with FETAL STRESS!

24. Positive feedback loop:
Mother’s brain
Positive feedback loop:
The hypothalamus (a part of the brain) sends a signal by way of the hormone oxytocin to the uterus causing contractions. The pressure of the fetus on the cervix sends a signal back to the brain which then stimulates the release of more oxytocin.
Uterus

25. Complications
What happens if the mother cannot give birth (puppies are too big, mother is too tired)
The veterinarian must perform a c-section

26. Nursing
It is extremely important for newborn puppies to drink milk from their mother
Not only does it provide a source of food that is easy to digest but it also gives the newborns immunity! (basically they are protected from certain diseases)

27. Key things to monitor in a newborn puppy
Weight gain: you want to know they are EATING (1 gram per pound of adult weight per day)
Temperature: puppies can become cold very easily and cannot shiver until 6 days old (keep environment at 86°F)
Mother has to help them urinate and defecate
Look for body defects
(cleft palate)

28. Fun facts and owner education
Open eyes from days 10-15
Open ears from days 15-17
Wean puppies at 3-4 weeks
Socialization period is 4-12 weeks of age

29. Let’s put it all together!
Day 78
Day 84
Day 1
Day 73
Day 91
Day 63
Gestation length
Embryo
Fetus
Conception
Eyes open
Wean
Birth
Ears open
Body fully developed
Start Socialization

30. In Summary…
The puppy is conceived and gets half the genetic information from the mother and half from the father
The embryo develops into a fetus that grows in the womb.
During the birthing process there are many hormones that are part a positive feedback loop that ultimately cause contractions.
Newborn puppies must be monitored closely to ensure they are eating, gaining weight and maintaining a proper body temperature.