THERIO - Breeding Management & Disorders Of Estrous Flashcards
What is unique to the canine reproductive cycle?
The only mammal that has a rise in progesterone before ovulation due to preovulatory luteinization of the follicles
What can progesterone assays estimate?
When ovulation will occur
What procedure helps determine the stage of the cycle and the first day of diestrus?
Vaginal cytology
What does trans abdominal ultrasonography help evaluate?
The stage of the cycle
Serum progesterone concentrations (ng/mL)
LH surge:
Ovulation:
Fertilization period:
LH surge 2.0
Ovulation 4-10
Fertilization period 12-16
How long does the canine oocyte take to mature?
48 hours
How long does semen last in the reproductive tract?
Fresh:
Chilled:
Frozen:
Fresh 7-11 days
Chilled 3-5 days
Frozen 24 hours; inseminate in uterus as close as possible to oocyte maturation
Six types of cells that typify vaginal cytology
Parabasal
Intermediate
Superficial cornfield
Anuclear cornfield
Neutrophils
RBCs
Considerations for canine breeding management
Goals
Medical history (m/f)
Reproductive history (m/f)
Physical condition (m/f)
Management, environment, care
Immunization, parasite control, brucellosis screening
Breeder’s experience and knowledge
Plan for breeding management
Evaluate bitch roughly _____ days after the beginning of proestrus.
4-5 days
When is blood drawn for the progesterone assay?
When vaginal cytology reaches 60% cornification
Good is drawn for progesterone assay every 3-5 days until _____.
Suggestive of LH surge (2 ng/mL) or ovulation (4-10 ng/mL)
Optimal breeding timing post-ovulation
Natural cover or AI with fresh/chilled semen:
Frozen thawed semen:
Natural cover with fresh/chilled semen: 2 days post ovulation
Two inseminations at two and four days post ovulation
Frozen thawed semen must be introduced when oocytes are mature; 3-5 days post ovulation
What are three alternatives to natural cover?
Fresh collected side-by-side artificial insemination
Insemination with chilled shipped semen
Insemination with frozen-thawed semen
Pregnancy rates with intravaginal insemination of chilled shipped semen:
60-95%
Insemination with frozen-thawed semen requires ____ insemination.
Intrauterine insemination
Describe the three fractions of semen.
1st - clear fluid (0.5 - 7+ mL)
2nd - white, opaque fluid / sperm rich (0.5 - 2 mL)
3rd - clear, primarily prostatic (5 - 30 mL)
What does semen evaluation include?
Volume, color, appearance of each fraction
Total number of spermatozoa in ejaculate
Motility
Morphology
*CASA enhances precision and accuracy
Definition of infertility
6 categories
Inability to conceive and produce a viable offspring in a specific timeframe
- Failure to have an estrous cycle
- Prolonged inter-estrus cycle
- Short inter-estrus interval
- Prolonged proestrus/estrus
- Failure to conceive/early reabsorption
- Failure to breed
Causes of primary anestrus
Congenital causes - ovarian aplasia, disorder sex development
Silent heat or inadequate estrus detection
- increase surveillance
- consider estrus induction
Stress related
Causes of secondary anestrus
Hormones - progestagens, mibolerone
Luteal cysts
Metabolic disorders - hypothyroidism, hyperadrenocorticism (Cushing’s)
Stress related
Three types of drugs for inducing estrus
Dopamine agonist - Cabergoline, Bromocriptine
GnRH agonist
Gonadotropins - LH, FSH
What are two side effects of dopamine agonists?
Coat color changes and vomiting
Ex: cabergoline, bromocriptine
Three types of abnormal interestrus intervals
Prolonged interestrus interval
Shorter interestrus interval
Persistent estrus
