SA - Manipulation of the Estrous Cycle Flashcards
What are the indications for induction of estrus?
Missing breeding opportunities, conception failure, treatment of primary or secondary anestrus (most common), and synchronization of ovulation for ET programs (research only)
Can we induce estrus in dogs?
Yes, but you need to respect the mandatory repair period in anestrus (90-150 days)
What can be used to induce estrus in dogs?
Synthetic estrogens, GnRH agonists, gonadotropins, and dopamine agonists
What synthetic estrogen can be used to induce estrus?
Diethylstilbesterol (DBS)
What GnRH agonists can be used to induce estrus?
Deslorelin*, Lutrelin, Buserelin, Fertirelin, and Leuprolide
What gonadotropins can be used to induce estrus?
LH, FSH, eCG, and hCG
What dopamine agonists can be used to induce estrus?
Cabergoline and bromocroptine
Is Diethylstilbesterol recommended? Why or why not?
Not recommended - the possible risks outweigh the benefits
What risks are associated with diethylstilbesterol use in inducing estrus?
Severe thrombocytopenia and aplastic anemia
What do GnRH agonists do to induce estrus?
They mediate the synthesis and release of LH and FSH from the anterior pituitary
What failure has been reported with GnRH agonist use to induce estrus?
Premature luteal failure which results in shortened diestrus and subsequent pregnancy loss
What Deslorelin implants can be used to induce estrus?
Suprelorin and Ovuplant - not approved in the US
Where are Deslorelin implants placed?
Subcutaneously either in the vulvular region or in the ventral abdomen
How quickly do Deslorelin implants work?
If given to an anestrus bitch, there will be reliable and rapid onset of estrus (7-10 days)
When should deslorelin implants be removed?
once ovulation is confirmed
What gonadotropins should not be used dogs because they show poor results?
LH and FSH
What side effects are associated with use of eCG?
Immune-mediated reactions, sudden death, and unpredictability of response
Are gonadotropins recommended for inducing estrus?
No because of the availability and side effects - not available in the US
What do dopamine agonists do to induce estrus?
They suppress prolactin secretion which shortens the duration of anestrus and will induce estrus if there is prolonged anestrus
What must precede induction of dopamine agonists?
anestrus - at least 120-150 days
Use of dopamine agonists may require ____ days of treatment?
30+ days
What dopamine agonists are available for dogs?
Cabergoline or Bromocroptine
What side effects are associated with Capergoline?
coat color changes and vomiting
What can induce estrus in cats?
FSH or hCG
What is the recommended drug of choice for inducing estrus?
dopamine agonists
What are the positives to using long acting preparations for inducing estrus?
convenient for owner and less stressful for the patient