Breeding management in the bitch Flashcards
Puberty in animals depends on (3)
size,
body weight/condition,
presence of a male
Puberty in dogs starts
Appears at 6-10 month in the smaller and up to 24 month in the larger breeds.
Duration and character of proestrus/estrus in bitches may differ during the puberty period:
- Less estrus behavior
- Shorter or longer duration of proestrus to estrus
- Reduced or inconsistent patterns of circulating estrogen, LH and
progesterone
More likely to manifest:
* Split or false heat (does not progress into estrus and does not ovulate)
* Silent heat
Describe The canine estrus cycle.
The dog is Monoestrus non-seasonal.
Typically 2 estrous cycles/year.
Proestrus 9 days (1-27)
Estrus 9 days( 4-24)
Diøstrus 70-90 days (3-4 months)
Anestrus/inter-estrus interval 5 months (4-12 months).
The duration of vulvar bleeding is individual (0-28 days).
Fertilizable 2-3 days after ovulation at 2. meiotic division?
Clinical changes during proestrus (4)
Seroanginous/bloody discharge from the vulva opening
The vulva is swollen and hard by palpation
The male dog is interested, but the bitch will not accept mating
Average duration 9 days
Clinical changes during estrus (5)
The discharge often turns more ”straw colored (not always)
Vulva remains enlarged but is usually softer than during proestrus
The bitch accepts mating
Average duration 9 days (4-24 days)
Ovulation occurs and the oocytes are fertilizable from 2 days- 6/7 days
post-ovulation.
Clinical changes during diestrus (4)
Is defined by characteristic changes in vaginal cytology
The bitch does not accept mating
The vaginal discharge has diminished
CL are functional and P4 is increasing.
planning before breeding (4)
Vaccinations:
distemper, parvo, hepatitis before mating and herpes during gestation
Maternal antibodies persist in the pups until 6-8 weeks of age at least.
Assessment of thyroid status (old bitch)
Blood chemistry/hematology (old bitch)
Deworming
Deworming in relation to breeding.
- Toxocara canis/catis: roundworm, infection of the bitch before pregnancy→ larvae remain dormant→ are reactivated in the last 3th of pregnancy →pass to the pups→ born infected and may produce a lot of eggs. Often infection via milk in dogs and cats
- Zoonotic disease – regular deworming and hygiene.
- Deworming 1 week before the delivery (parturition activates the larvae) (panacur-fenbendazole or milbemax).
- The pups are treated approximately 2 weeks post partum and another 1-2 times
before leaving the mother. - Uncinaria/ancylostoma (hookworms): not uncommon in hunting kennels.
- Taenia can happen too.
Organogenesis ends when in cats and dogs?
Day 35
which is why we deworm after gestational day 35, 1 week before parturition.
The first litter should be at what age in dogs.
The first litter at 2 years and not later than 6 years of age.
The last litter at 8 years of age (breed dependent).
The 3.estrous more fertile than the 2 first ones.
Most important 3 methods to detect estrus and ovulation in order to choose optimal time of breeding. (3)
Vaginal cytology
Vaginoscopy
Progesterone
Optimal time of breeding in relation to estrus. Two periods to consider.
Fertilization-period:
oocytes can be fertilized in this period.
- 2 days after ovulation, 4 days after LH-surge
The fertile period is the time during which mating could result in conception.
- 5 days before and 5/6 days after ovulation,.
Canine sperm can live for up to 8-9 days within the vaginal lumen.
Describe Vaginal cytology
Changes in exfoliated vaginal epithelial cells occur as a results of the change in
secretory levels of estradiol.
Increase in estradiol stimulates the growth of vaginal epithelium from a few layers in thickness during anestrus to 20-30 layers in thickness during proestrus.
When estradiol concentration decreases → endocrine support of these new cell layers of stratified epithelium diminishes and there is a marked increase of dead
cornified cells that are sloughed off.
The change in the percentage of superficial cells in a vaginal smear can be used to monitor the progression of proestrus and estrus and predict the optimal time of breeding.
Describe the process of vaginal cytology sample taking.
Flexible cotton swab moistened with water.
Take the swab through a speculum from the cranial vaginal wall, NOT from the vestibule.
Use staining method like Diff quick.
Microscopic evaluation at 10 x magnification or 100x with oil.
You may see parabasal-,
intermediate- ,superficial cells, bacteria, neutrophils.
Parabasal cells look like sunny side up eggs. Big well defined nucleus in a round cell, not too much cytoplasm.
Anestrus
Intermediate cells (small and large), nucleus has begun to shrink from earlier size.
Proestrus
Nucleated superficial cells at end of pro-estrus, beginning of estrus.
Erythrocytes not unusual.
Nucleated superficial cells at end of pro-estrus, beginning of estrus.
Erythrocytes not unusual.
Anucleate superficial cells in estrus. You may see cell clustering/nest formation due to cellular degeneration.
60-80% anucleate superficial cells in
estrus, There is no signifant change in this
percentage until diestrus.
Therefore vaginal cytology can’t be
used alone to set the optimal time of
breeding.
60-80% anucleated superficial cells in
estrus
Beginning of diestrus. If you see this its Too late to mate the dog.
Parabasal cells and neutrophils
Diestrus
With Vaginal endoscopy, you can assess
The degree of edema in the vulva and vaginal mucosa which correlates to the level of estradiol in the blood. Use this in combination with other methods such as vaginal cytology.
In proestrus, when this level is high, edema and hyperemia of the mucosa is present.
This disappears towards estrus, where the vulva becomes more soft and the mucosa appears less edematous and the folds looks wrinkled (angulated) and pale.
Describe Measurement of progesterone (P4) in dogs:
P4 increases from baseline 2 days before ovulation at the time of the LH-surge (unique for the dog).
- Values between 5-7 ng/ML at the day of ovulation depending on the assay
- The initial rise is gradual → only necessary to collect blood every 2-3 days prior to ovulation.
- Mating should be 4-6 days after the LH-surge (about 2 ng/ml) or 2-4 days after the ovulation.
- At ovulation → steep rise in progesterone compared to the preovulatory period.
If nmol/l the value in ng/ml should be multiplied by 3.1.
How do you differentiate late proestrus and estrus on cytology?
very similar except that in estrus the nuclei are gone but in proestrus they’re still visible
Bitch serum P4 under 1 indicates?
anestrus or proestrus
Bitch serum P4 under 1.0- 1.9 indicates?
ovulation to occur in approx. 3 days
Bitch serum P4 under 2.0- 2.9 indicates?
ovulation to occur in approx. 2 days, LH peak
Bitch serum P4 under 3.0- 5.0 indicates?
ovulation to occur in approx. 1 day
Bitch serum P4 when fertilization period is occuring?
between 10-20 ng/ml
