- For an excellent review see: Estrus
induction and synchronization in canids and felids, M.A. Kutzler,
Volume 68, Issue 3, August 2007, Pages 354-374 Proceedings
of the Annual Conference of the Society for Theriogenology,
Proceedings of the Annual Conference of the Society for
- Before inducing estrus, it is important that the
bitch has undergone the mandatory endometrial repair period.
Attempting to induce estrus in a bitch that is in diestrus, or
that has not completed endometrial repair following the luteal
phase will surely result in infertility.
Normal Induction of Estrus
- FSH concentrations are high and LH
concentrations are low during most of anestrus.
- Both FSH and LH increase progressively at the end
of the anestrus period. The rise in the LH concentration
causes folliculogenesis at the end of anestrus.
- Gonadotrophins are compounds which have
stimulating effect on the ovary.
Follicle stimulating hormone (FSH), Equine chorionic gonadotrophin (eCG) (formerly named Pregnant mare serum gonadotrophin -
There are many reports using these compounds are
results have been extremely variable.
The very successful report by Moses and Shille
and FSH has never been reproduced
clinically (even by Shille).
Availability of the gonadotrophins is also
variable, with some products available at some times, and not
abstract from Argentina
- PG 600 is marketed for inducing estrus in
- It has been shown to be clinically effective in
- One 'dose' followed by second dose in 7 days was
clinically effective at inducing estrus in 17/19 bitches.
- It was noted however, that if it was given during
proestrus, superovulation may result.
- You must use a surgically implanted pulsatile
releasing hormone causes release of FSH
and LH from the anterior pituitary. It is not a gonadotrophin. The
natural FSH causes the follicular growth.
- These pumps are hard to get, cumbersome to
install, expensive, and not that reliable.
analogue Deslorelin (Ovuplant)
- Ovuplant is the equine implant containing 2.1 mg
- Placed in vestibular mucosa
- Progesterone followed
- Implant removed day of LH surge (as determined
- 0-13 days (50% on day 9 post implantation)
- Day 1 diestrus 14-18 days
- 5/7 conceived
- Deslorelin 2.1 mg implant in
vestibular submucosa once (proestrus within 5–6
d) 100% ovulated good pregnancy rate (several
- Cannot get the implant from
the company in 2004, but some compounding
pharmacies have it (BET).
- In a study done at LSU were
induced a progesterone rise (estrus?) in 14/16
Diethylstilbestrol - DES (Bouchard
- This seems as though it is the most reliable yet.
- You may not be able to obtain DES anymore.
- Make sure the bitch has completed endometrial
repair i.e. the interestrus interval is 150 days.
- Administer 5 mg Diethylstilbestrol (DES) PO for 7
days or until bleeding starts.
- Give DES 2 more days after bleeding is observed.
Count the first day of bleeding as the first day of the induced
- Experimentally 5/5 conceived and averaged 6.3
pups/litter. We have had success using this technique.
- Currently not commercially available, but as of
4/1/99 (not an April Fools Joke) is available at Portland
Professional (207-774-5440), a formulating pharmacy and in
Lafayette, LA "Professional Arts Pharmacy" 318-237-4767
- In a study done at LSU we
were 0/5 at inducing estrus.
Action of dopamine agonists in
mechanism by which dopamine
agonists shortens anestrus is
not yet known.
Link to a review
article in Communications in
Theriogenology (Vol 1 Issue 1)
on estrus induction with
dopaminergic action on either the
gonadotrophic axis or on ovarian
does increase FSH concentration that
results in enhancement of follicle
development, but there is no
correlation between PRL and LH, and
there is basal PRL concentration
found during anestrus.
- There is a direct
stimulating effect of dopamine in
the synthesis of gonadotrophin
releasing hormone (GnRH) by
hypothalamus-hypophysis neurons, but
the role of the dopaminergic paths
in the control of gonadotrophin
secretion is still unknown in the
bitch. Dopamine agonists may have a
have a direct effect on the ovaries.
Cabergoline might mature
gonadotropin ovarian receptors by
its dopaminergic agonist action.
Dopaminergic agonists may act by
either releasing gonadotrophins or
by an action on ovarian tissue.
- Administered at a dose of 50 ug/kg, BID until
- It may take 18-28 days of treatment before estrus
- Experimentally 4/5 bitches came into proestrus,
but fertility was not monitored.
- Another study used bromocriptine in 4 bitches
orally at 20mg/kg twice daily. A
pregnancy rate greater than 60% was obtained using the same
bromocriptine protocol in a study that compared administration
from the onset of the luteal period or from about 21 days after
the onset of the luteal period
- Lutalyse does not really induce estrus, but if it
is given during diestrus the next cycle will be about one month
sooner than it normally would be.
- This could be useful in breeding colonies. If a
bitch is not pregnant, prostaglandin could be given to shorten the
time to the next heat. This would result in more potential puppies
in a given time.