Principles of Contraception, Incomplete Ovariectomy Flashcards
what does neutering a male not decrease the risk of
prostatic neoplasia
What reproductive hormone treatment can be useful for palliative management of prostatic neoplasia
long acting GnRH agonist (deslorelin)- causes initial stimulation then down regulation of FSH and LH
what does short-term GnRH agonist do
causes stimulation of LH and FSH release
What can deslorelin be used for
is a long-acting GnRH agonist
can be use to inhibit reproduction in males and females of all species (dose-dependant)
effects of progestogens
Exert powerful negative feedback effect upon the hypothalamus/pituitary
What are progestogens used for
control of oestrus
prevention= Administration in anoestrus to prevent occurrence of oestrus
Describe how progestogens can be used to treat pseudopregnancy
Progestogens inhibit the release of prolactin from the pituitary gland
Describe how progestogens are used in males
cause reduction in FSH and LH secretion
LH- reduces steroidogenesis
FSH- reduction in spermatogenesis
Can be used to treat antisocial behaviour
prostate disease
anal adenoma
what is the most important side effect of oestrogens that we need to be aware of
bone marrow supression
Describe how oestrogens can be used to treat unwanted mating
Prevention of implantation and / or interference with transport of zygotes
But animals may continue to show signs of oestrus
How does oestrogens help with urinary incontinence
Increase urethral mucosal thickness
List 2 situations when topical oestrogens are used to treat vaginitis
Pre-pubertal
Atrophic
what do androgens do
mimic the action of testosterone
will induce temporary infertility in males
what is hCG similar to
has LH- like action
List situations when we may use hCG in dogs
testing gonadal function
hastening of ovulation
forcing of ovulation
List 2 actions of prostaglandins
lysis of CL - early CLs may not respond
ecbolic
At what point in the dog will the CL respond to prostaglandin
after day 20?
needs frequent dosing every day- due to prolactin
List 3 situations that can be treated with prostaglandin in the dog
open- cervix pyometra
termination of pregnancy
post-partum meteritis
generally used in combination with other drugs
List 3 uses of oxytocin
Contraction of uterine smooth muscle when receptors are present
Pharmacological contraction of uterine smooth muscle when few receptors are present
Milk `let-down‘
when should oxytocin not be used
if cervix is closed or in cases of obstructive dystocia
List 4 clinical uses of oxytocin
Stimulation of uterine contraction to facilitate parturition in the presence of a fully dilated cervix
Promote involution of the post-parturient uterus and thus aid the passage of retained placenta
Aid in the control of post-partum haemorrhage
Promotion of milk `let-down’ in cases of agalactia
when does prolactin increase in the bitch
increases from approx day 25 after ovulation
what do prolactin inhibitors do
Removal of prolactin causes demise of the CL’s
Progesterone rapidly declines
Termination of the luteal phase
Does prolactin inhibitors have an effect in the early luteal phase
No
List 2 licensed uses of prolactin inhibitors
Treatment of Pseudopregnancy
Suppression of Lactation e.g. Post weaning
List 3 off licensed uses of prolactin inhibitors
To end the luteal phase to terminate pregnancy (often done in combination with prostaglandin)
To end the luteal phase to treat pyometra (often done in combination with prostaglandin)
To induce oestrus (mechanism uncertain)
how should you treat a closed cervix pyo
prolactin inhibitor then once open give prostaglandin
Describe why you should not give prostaglandin to a dog with a closed cervix pyometra
If cervix is closed in pyo and you give prostaglandin, there is a risk of a tear in the uterus as you are causing it to contract against a closed cervix
List 3 potential uses of progesterone receptor antagonists
Prevention of implantation
Termination of pregnancy at any stage
Treatment of pyometra?
How does a melatonin implant work in sheep
Melatonin implant administered at base of ear in May-June to hasten onset of cyclicity (+ introduction of the ram)
what do melatonin implants do in long-day breeders
down-regulation of endogenous production
List 2 drugs that could be used to treat non-ovulating follicles in bitches
hCG
short-acting GnRH
List 4 situations that a ovariectomy may result in uterine disease
the uterus was already abnormal
you leave an ovarian remnant
there is a neoplasm producing reproductive steroids
exogenous reproductive steroids are administered
At what point should we spay a bitch - why
greater than 12 weeks after oestrus - so we don’t induce an iatrogenic pseudopregnancy
Or within Weeks 3 and 4 post oestrus before prolactin is turned on so you don’t induce pseudopregnancy
At point does infertility occur after stallion is castrated
Stallions have significant ampulla therefore sperm may be detected for several weeks or until he ejaculates
At point does infertility occur after dog is castrated
very small ampulla therefore azoospermatic within a few days
Describe how incomplete ovariectomy cases present
Oestrus behaviour
List some ways to diagnose a incomplete ovariectomy
observation of behaviour
vaginal cytology
ultrasound of ovaries
measurement of progesterone
Describe how to diagnose incomplete ovariectomy in queen
generally cycle every 2-3 weeks
examine when they are in alleged oestrus
