Reproductive System Flashcards
(177 cards)
Describe the three phases of the canine estrus cycle
- Proestrus:
Estrogen rises –> vulva enlarges –> serosanguinous vaginal discharge –> attraction of males - Estrus:
Estrogen declines –> triggers LH surge –> ovulation –> female is receptive (behavioral estrus) –> progesterone begins to rise - Diestrus:
Progesterone is secreted from corpus luteum –> uterus prepares for implantation
Describe the role of progesterone
Produced by ovary after heat (estrus)
o After ovulation, follicle corpus luteum –> makes progesterone (diestrus)
o Required for normal pregnancy
Stimulates endometrial glands (increasing number and secretion) and prepares wall for fertilized ovum
What are the types of ovarian cysts?
Non-functional: incidental finding typically discovered when imaging/routine OHE
o Minimal to no clinical signs, may be identified at any age
o Surgical excision is curative, still want to submit for histopathology
Functional: hormone producing, arise from ovarian follicles
o Follicular cysts produce estrogen (most common)
o Luteal cysts produce progesterone (rare in dogs)
What are the clinical signs associated with the most common type of functional ovarian cyst?
Follicular cysts
Causes prolonged stage of estrus
What type of ovarian cyst might be associated with pyometra?
Progesterone-releasing cysts
What is the signalment associated with ovarian cysts?
Young adults (dogs
What is the treatment and prognosis of ovarian cysts?
Surgical excision is curative
Why can pyometra be associated with ovarian neoplasia?
Chronic release of progesterone as in a functional granulosa cell tumor causes endometrial hyperplasia and immunosuppression of the uterus, making bacterial proliferation more likely
What are the different tissues of origin for ovarian neoplasia and why is tissue-type significant?
Tissue of origin dictates effects of tumor
Epithelial: adenoma/adenocarcinoma - space occupying masses only
o Causes vague signs of inappetance, vomiting, lethargy, etc.
Stromal: granulosa cell tumor - functional
o Progesterone –> pyometra
o Estrogen –> persistent proestrus/estrus
Germ cell: dysgerminoma, teratoma, teratocarcinomas (tend to occur in young animals)
What is the general likelihood of metastatic disease with ovarian neoplasia?
Uncommon, 20-30%
Is metastatic ovarian disease more common in dogs or cats?
Cats
What is the significance of a metastatic, functional ovarian tumor?
More complicated than simple excision, but adjunctive treatment may improve survival
Functional tumors (estrogen) can cause irreversible bone marrow suppression
What is the prognosis for a solitary (non-metastatic) ovarian tumor?
complete exision is curative
What is the etiology of ovarian remnant syndrome?
Surgical error - ovarian tissue left behind at OHE, or tissue dropped into the abdomen that has revascularized
What are the clinical signs of ovarian remnant syndrome?
Recurrence of estrus cycle (even 2-3 years later)
Vulval swelling, behavioral estrus
Why is vaginal bleeding not typically seen with ovarian remnant syndrome?
The uterus has been removed
How is ovarian remnant syndrome diagnosed in the dog?
- Vaginal cytology (easiest)
o Mimics normal heat cycle, must be done in standing heat
o Inconsistent in cats - Hormone assays
o Elevated estrogen and progesterone, low LH
o Cats may require lutenization first
Where should you look for the remnant when treating ovarian remnant syndrome?
Caudal pole of right kidney
How does ovariectomy differ from OHE?
Removal of ovary alone
o No risk of secondary effects (eg. pyometra) because hormones have been removed
Ligate ovarian vessels as for OHE –> ligate uterine vessels at proper ligament –> excise ovary
Which hormone is necessary for pyometra?
Progesterone
What is the most common bacteria found in pyometra?
E. coli
What are the typical historical findings of a dog with pyometra?
Recent heat cycle (4-8 weeks ago) Polyuria/polydipsia Systemic illness – variable (anorexia, lethargy, vomiting, fever) Abdominal pain/guarding Vaginal discharge – purulent
Why is PU/PD associated with pyometra?
PU/PD caused by bacterial toxins that inhibit ADH in PT of kidney
What is the difference between open and closed pyometra, and how does that relate to severity of systemic signs?
Open cervix - discharge seen, but less systemically severe
Closed cervix - more severe