Dog Reproduction and Estrous Cycle

Consists of four stages: Anoestrus, Pro-oestrus, Oestrus, and Meta-/Dioestrus.
Pro-oestrus lasts approximately 10 days, where females exhibit hormonal changes.
Oestrus follows, also lasting about 10 days, characterized by receptiveness to mating.
The Luteal Phase lasts around 2 days, which involves hormone production from the corpus luteum.
Anoestrus usually lasts about 4.5 months, a period of reproductive inactivity.

Weak straining persists for over 2-4 hours.
Strong straining lasts more than 20-30 minutes without progress.
No progress occurs 2-3 hours after fetal fluid release.
If a puppy is due to be born in 2-4 hours but no green discharge appears.
Post-delivery, if the queen has no discharge or it is red-brown for more than 2-4 hours.
Failure to expel after more than 12 hours in the second stage of labor.

Anoestrus: Dominated by oestrogen, lasts 4.5 months.
Pro-oestrus: Approximately 10 days, prepares the reproductive system for mating.
Oestrus: Also lasts about 10 days; the period of receptivity to mating.
Luteal Phase: Lasts around 2 months, characterized by high progesterone levels.
Average Gestation Period: Approximately 64 days from conception.

Weak straining persisting for more than 2-4 hours may indicate complications.
Strong straining for over 20-30 minutes requires immediate attention.
If no activity has occurred 2-3 hours post-passing of fetal fluids.
The presence of a puppy within 2-4 hours of green discharge or red-brown in queens.
If more than 2-4 hours have elapsed since the last puppy and more are expected.
More than 12 hours in the second stage of expulsion signals a potential issue.

Oxytocin: Used to start or continue labor, contraindicated in obstructive dystocia.
A recorded body temperature exceeding 39.5°C is a sign of potential complications.
If the placenta has not been expelled within 4-6 hours, intervention is necessary.

At 25 days gestation, abdominal palpation can detect pregnancies as early as Day 21-32.
Puppies can be balloted starting at 30 days of gestation.
Ultrasonography can confirm fetal heartbeats between 24-28 days.

Occurs naturally in all entire non-pregnant bitches; also seen in queens after sterile mating.
Characterized by elevated prolactin levels.
Typically resolves after 'parturition' or simulated birthing behavior.

Based on progesterone level exceeding 1.8 ng/mL as an indicator:
- +1 day prediction accuracy: 67%.
- +2 days: 90%.
- +3 days: 100%.
Notable drop in body temperature can signify imminent parturition.
Progesterone levels above 5 ng/mL are relevant later in pregnancy.