Mismating Management, Contraception, Ovarian Remnant Syndrome Flashcards
Mismating initial consult
- is she in heat
- was a tie observed
- how long was bitch missing
- are puppies wanted
- is the bitch a breeding animal
- will you let me spay her (pyometra/neoplasia)
Perform ______ on all mismatched bitches
Vaginal cytology
- want to determine where she is at in her cycle
- look for sperm heads (24 hrs after breeding, 75% in 48 hrs)
- run P4 to confirm if needed
Goals of mismating
- limit treatment to dogs at highest risk or those confirmed pregnant
- do not want to affect future fertility
- do no harm
First opportunity to confirm pregnancy in a dog
22-24 days
- do an ultrasound
Options for pregnancy termination
- ovariohysterectomy
- prostaglandin
- estrogen
- prolactin inhibitors
- corticosteroids
- progesterone anatgonists
Examples of prostaglandins
Lutalyse and Estrumate
Prostaglandins - mode of action
Direct luteolytic action with multiple doses (canine CL are resistant early in pregnancy)
- removes source of progesterone
- causes myometrial contractions
- dilates cervix
- pregnancy is expelled
Prostaglandins - side effects
Therapeutic dose is relatively high compared to large animals, and they are sensitive to it
- panting
- excessive salivation
- vomiting
- diarrhea
- begins within 5 min and lasts 20-30 min
- subside with repeated use
- bitch may return to estrus sooner
How to minimize side effects of prostaglandin
- give on empty stomach
- start with lower doses and increase
- dilute with saline
- walk immediately after injections
- atropine
- pregnant women and people with asthma handling prostaglandins should take extreme care!
Estrogens
Can be used only during estrus!
- good client communication and consent is important
- do not use in valuable breeding bitch
______ is the only product that can be used at the time of mating to prevent pregnancy!
Estrogen
Estrogen - mode of action
Tightens utero-tubular junction
- kink formed in oviducts
- delays tubular transport of embryos
- alters estrogen:progesterone ratio leading to implantation failure
- direct embryotoxic effect
- collectively leads to failure of pregnancy maintenance
Estrogen - side effects
- pyometra (if treated during diestrus)
- bone marrow suppression
- prolonged estrus
- infertility at subsequent cycles
Estrogen products
- estradiol cypionate
- estradiol benzoate
- diethylsilbesterol (DES) is NOT effective mismating agent
Corticosteroids - mode of action
High cortisol levels cause fetal production of prostaglandins leading to abortion
- may have direct luteolytic actions
- exact mechanism not fully understood
Corticosteroids - side effects
- anorexia
- PU/PD
- short duration
- subside after medication is discontinued
Corticosteroid - products
Dexamethasone
- always start after day 30 of gestation
- always confirm pregnancy loss
Prolactin inhibitor - products
- parlodel
- dostinex
PRL - mode of actions
Increases dopamine release
- dopamine inhibits prolactin release
- prolactin is primary luteotropin in bitch
- low prolactin levels lead to low progesterone levels
- low progesterone = abortion/pregnancy loss
PRL inhibitors - side effects
- nausea, vomiting
- anorexia
- diarrhea
- seen commonly with bromocriptine
- rare with cabergoline (more selective dopamine agonist)
PRL inhibitors always start _____
After day 30 of gestation
- confirm pregnancy loss at end of treatment
Progesterone antagonists
- mifepristone (not available in US)
- aglepristone: requres 2 shots, 24 hrs apart as early as 3rd week of gestation
Notes to remember
- failures occur when follow up is neglected
- progesterone levels of <1 at completion assure luteolysis
- make owners aware of expectations
- don’t make abortifacient use the cheap alternative to spay
Intratesticular injection of sclerosing agents
Neutersol/Esterilsol
- scleroses the testicle to damage ability to produce sperm (does not eliminate it totally)
- low chance of achieving pregnancy
- some effect on testosterone
GnRH vaccines
Gonacon
GnRH agonists
Gonazon, suprelorin
- reversible, down regulates hypothalamic pituitary gonadal axis
GnRH antagonists
Acyline
Neutersol/Zeuterin/Esterilsol
Zinc gluconate
- intratesticular injection
- results in sterility due to destruction of sperm production
- some effect on testosterone production
Ovariectomy
Uterus is left, but ovaries are removed
- fewer complications reported with ovariectomy
- common in European countries
Ovary sparing spay
Ovaries remain
- must remove cervix or pyometra
- lots of owner counseling/understanding
Vasectomy
Only renders male sterile, but still will have testosterone present
- castrate and prosthesis is alternative
Flank spay in cats
Used in cases of mammary hyperplasia
Hormone profile of ORS females
- elevated anti-mullerian hormone level
- confirm rising P4 2 weeks later (P4>2 confirms presence of luteal tissue)
- high estrogen
- LH concentration is low on 2 separate tests
ORS - things to consider
- LH rises slowly and variable in spayed female
- high P4 and E2 confirmatory, but low values are not predictive enough
- unstimulated P4 testing doesn’t work in cats
Side effects of ORS medical management
Megestrol acetate (ovaban) or mibolerone (cheque)
- mammary gland tumors
- acromegaly
- clitoral enlargement
- adrenocortical suppression
