Abnormal Cycles Flashcards
What is the normal length of the canine interestrus interval? (range)
4-12 months, its usually 6-8 months.
What is the typical length of diestrus in dogs?
2 months
what is the typical length of estrus in the dog?
9 days
what is the typical length of proestrus in the dog?
9 days
What are the 2 types of persistent anestrus?
- primary anestrus – lack of estrous cycling by 24 months of age
- secondary anestrus – prolonged interestrus interval (failure to cycle >12 months after a previous estrous cycle)
What 3 drug types can cause persistent anestrus?
- progestins
- androgens
- glucocorticoids
T/F: increased activity/stress and plane of nutrition can cause persistent anestrus
true
How can you prevent persistent anestrus that is caused by silent heat? (3 ways)
- daily observation and wiping of vulva
- weekly/biweekly vaginal cytologies
- monthly+ serum progesterones
what are 4 ovarian disorders that cause persistent anestrus?
- congenital abnormalities (ovarian agenesis, ovarian hypoplasia, atypical gonads)
- oophoritis
- luteal cysts – sustained progesterone
- granulosa cell tumors – secrete progesterone
What length of heat would be classified as ‘persistent heat’?
> 6 weeks of combined proestrus and estrus OR significantly longer heat relative to the normal heat cycle for that particular bitch
remember normal heat = 2-3 weeks
What 3 ovarian disorders can lead to persistent heat?
- follicular cysts
- granulosa cell tumors – secrete estrogen
- oophoritis
If a bitch presents to you because her owners report she has been in heat for 7 weeks, what is the first question you should ask them when obtaining history?
Ask them if the dog has been given any estrogenic medications or could the dog be in contact with someone taking estrogenic medications
What are other diseases that cause prolonged vulvar discharge and are mistaken for persistent heat?
pyometra
vaginitis
__________ can cause uterine diseases (CEH, endometritis, pyometra), bone marrow suppression** (aregenerative anemia, leukopenia, and thrombocytopenia), skin changes (alopecia, hyperkeratosis), and mammary gland development.
Persistent heat –> prolonged estrogen exposure
__________ is a short proestrus period without ovulation followed 2-12 weeks later by normal fertile ovulatory heat
split heat
this most often occurs at pubertal heat and is considered normal in bitches under 4 yo, but you should probably still look into it further.
What will result if serum progesterone never rises above 3.5 ng/mL?
ovulation failure
If ovulation failure occurs, when would you expect the NEXT heat to occur?
2 months earlier.
Therefore, ovulation failure will shorten the interestrus interval
T/F: medical abortions and pyometra treatments cause irregular interestrus intervals
true
How can uterine disease cause irregular interestrus intervals?
uterine disease/inflammation –> prostaglanding (PGF2a) production –> premature luteolysis occurs
what 5 ovarian pathologies can cause irregular interestrus intervals?
- granulosa cell tumors – secretes progesterone
- follicular cysts
- congenital abnormalities
- luteal cysts
- oophoritis
What drugs can cause irregular interestrus intervals?
- mibolerone
- MGA / progestins
- GnRH superagonist implants
Which systemic endocrine disease causes irregular interestrus intervals?
hyperadrenocorticism
T/F: younger bitches are more likely to experience irregular interestrus intervals than older
false – older
T/F: irregular interestrus intervals occurs after whelping
true
which type of ovarian tumors are MOST common?
epithelial tumors such as adenocarcinoma and others.
2nd most common = sex cord/stromal tumors such as granulosa cell tumors, etc.
3rd most common = germ cell tumors such as teratomas, etc.
What would you see on vaginal cytology if a bitch were in estrous?
cornified superficial epithelial cells
what are 2 potential sources of estrogen?
ovaries
adrenal glands
If a bitch presents to your clinic because the owners report she is 34 days in heat and has abdominal discomfort, what would be some appropriate diagnostics to run on this dog?
- Physical exam
- vaginal cytology (to look for estrogen influence and/or inflammation)
- serum progesterone levels (determine ovulation status and to see if CL is present)
- ultrasound (to look for intraluminal fluid, uterine and ovarian appearances, and adrenal glands)
- CBC, Chem, UA, serum T4 (looking for bone marrow suppression, systemic inflammation, infection, etc.)
T/F: if you do not know the cause of persistent heat, you should not prescribe progesterone or any other medications that would attempt to decrease estrogen levels.
TRUE
without knowing the underlying cause, this is not safe. It can cause pyometra.
You can safely perform an OHE.
If a dog has a history of being spayed, but presents to you because the owners report she keeps having signs of heat (swollen vulva, male dogs interested, mucoid light brown vulvar discharge) what is your top differential?
ovarian remnant
T/F: with ovarian remnants, you expect to see either serosanguinous discharge (ovariectomy) or no discharge at all (OHE)
true
What vaginal tumors are hormone-dependent supporting the presence of ovarian tissue?
fibropapillomas or leiomyomas
What AMH test result is consistent with a SPAYED female dog or CASTRATED male?
NEGATIVE
Serum P4 < ___ equals a negative test.
0.2 ng/mL
Serum P4 > ___ equals a positive test.
0.5 ng/mL
What result on an LH test indicates presence of ovarian tissue?
NEGATIVE
