Sequoyah German Shepherds
Take a look at the page below to see some orphans that
need a loving home!
|
Last
updated 9/16/13
The Whelping Box —
Managing the Prospective Mom
By Carolyn Russell Gold
Responsible breeding involves much preparation beforehand,
including careful research and self-education by the breeder
as well as ensuring that the bitch is healthy and ready for
breeding. The following information on preparing the bitch
for breeding is based on interviews with and information
drawn from articles provided by Autumn Davidson, DVM, MS,
Dipl. ACVIM, VMTH SAC, of the School of Veterinary Medicine
at the University of California, Davis. Dr. Davidson kindly
responded to the following questions about the bitch’s
reproductive cycle and managing the prospective dam.
Q: How does a breeder begin breeding management
of the female prior to breeding?
A: The canine estrous cycle consists of four phases:
proestrus, estrus, diestrus, and anestrus.
Proestrus and estrus are commonly called “heat” or “season.”
During proestrus, the start of the estrous cycle, the female
attracts male dogs but is still not receptive to breeding.
Q: What happens next?
A: The female may become playful or passive as proestrus
continues. A blood-tinged vaginal discharge (of uterine
origin) is present; the vulva is moderately enlarged and
turgid. Cells from vaginal cytology smears change over a
period of four to seven days from non-cornified (small
“parabasal” cells and small and large “intermediate” cells)
to cornified cells (“superficial-intermediate” cells and
“anuclear” cells).
Q: What do these changes in vaginal cytology
mean or signal to the breeder?
A: These changes reflect increasing estrogen from the
ovarian follicles. Red blood cells are usually, but not
invariably, present. Proestrus can last from three days to
three weeks, with nine days the average. Proestrus
progresses to estrus.
Q: What happens during estrus?
The normal female displays receptive (or sometimes, passive)
behavior, enabling breeding to occur. Vaginal discharge
normally diminishes at this time, and it may become
lighter in color or even be clear. Vulvar edema tends to be
maximal and the vulva flaccid to facilitate breeding.
Vaginal cytology during estrus consists of 80 to 100 percent
cornified cells. Red blood cells tend to diminish but
sometimes persist throughout estrus.
Q: How long does estrus normally last?
Estrus can last three days to three weeks, with nine days
being the average. Receptive behavior begins when estrogen
concentrations decline and progesterone concentrations
increase. The duration of receptivity to male dogs is
variable and may not coincide precisely with the fertile
period, which occurs during estrus.
Q: When does ovulation occur?
A: Ovulation is triggered by a surge in the luteinizing
hormone (LH) produced by the pituitary gland. Ovulation of
immature, infertile primary oocytes (eggs) begins
approximately two days after the LH surge; oocyte maturation
occurs over the following one to three days. The life span
of the secondary (fertile) oocytes is two to three days. The
female’s actual fertile period extends from three
through six to seven days after the LH surge. The LH surge
occurs at the same time as an initial increase in
progesterone concentration, enabling ovulation timing by
measurement of either hormone.
Q: How does the breeder time ovulation?
A: Ovulation timing should be performed using a combination
of serial vaginal cytologic exams, ideally serum (blood)
progesterone concentrations. Testing for LH can be used in
some cases (such as for infertility or frozen-semen
breedings).
Start vaginal cytology exams during the first few days of
proestrus; perform every two to three days. When more than
70 percent of the epithelial cells are cornified
(“superficial” cells), serum progesterone testing should be
done every 48 hours to detect the day of initial
progesterone rise (usually between 2 to 3 ng/ml), which
correlates with the LH surge triggering ovulation. That is
called “day zero.” The female is most fertile, and can be
bred with good conception rates, between two and seven days
after “day zero.” The number of breedings and the optimal
day(s) of breeding depends on the type of semen (fresh [e.g.,
live-cover or trans-cervical insemination],
chilled/extended, or frozen).
If LH testing is used to determine the most precise
ovulation timing, daily serum samples must be taken once the
vaginal cytology contains more than 70 percent “superficial”
cells. Initial rise in progesterone or occurrence of the LH
surge is confirmed around 48 hours later by running an
additional progesterone test. At the time of breeding,
progesterone should be above 5 ng/ml.
To economize ovulation timing, daily serum samples can be
saved (refrigerated or frozen) and selected for later LH
testing based on estimated initial rise in progesterone.
Q: How does a breeder manage a “maiden” bitch?
A: Primiparous (maiden) bitches should have a
veterinary exam prior to breeding to ascertain general
health, and specifically to rule out problems (vaginal
strictures and inverted nipples) that could arise during
breeding, whelping, or nursing.
A discussion with your vet about the canine estrous cycle,
ovulation-timing techniques, and breeding management, as
well as guidance in performing screening tests for genetic
diseases common to your breed, should take place prior to
mating.
A screening test for Brucella canis is advised
annually for stud dogs and before each breeding for brood
bitches. Brucella testing should occur even in the
maiden bitch, as the infection can be transmitted without
breeding.
Vaginal cultures are not necessary for healthy bitches;
normal vaginal flora is not harmful to stud dogs nor
detrimental to conception.
Also, the vet staff and client need to come to an agreement
beforehand concerning the management of dystocia,
or difficulty in whelping, should it occur.
Q: There are different methods of accomplishing
a breeding. What are they?
A: Conception is most likely with a “live cover,” or natural
breeding, with “ties.” But artificial insemination (AI)
breeding, using a fertile stud dog and proper timing
techniques, can be highly successful. AI is needed when
using fresh-chilled or frozen semen, as well as with
geriatric or inexperienced stud dogs or aggressive bitches.
AIs are best accomplished using a clean, rigid, mare uterine
infusion pipette, allowing placement of semen near the
cervical opening in the upper vagina. The successful use of
frozen semen requires intrauterine deposition, now possible
with rigid endoscopy through the cervix, transcervical
insemination (TCI) being an additional tool for experienced
vets, reducing the possible need for surgical implantation.
Another option when using frozen semen is surgical
implantation.
Q: After the bitch is bred, if she is not in
whelp, what would a breeder expect to see?
A: Following estrus and breeding, the bitch enters
diestrus. During diestrus, the normal bitch becomes
refractory to breeding, less attractive to males. Vaginal
discharges become mucoid and diminished, and vulvar edema
slowly resolves. Vaginal cytology is altered by reappearance
of noncornified (“parabasal”) epithelial cells and,
frequently, white blood cells. Diestrus usually lasts about
two months in the absence of pregnancy. Bitches normally
experience a false pregnancy if not actually pregnant at the
end of diestrus.
Q: What happens after diestrus?
A: After diestrus the bitch enters anestrus. The
interestrus interval (the period between outwardly apparent
hear cycles) consists of diestrus and anestus and normally
varies from four and a half to 10 months in duration, with
seven months the average.
Q: What is the anestrus phase?
A: The anestrus phase is characterized physically by
apparent reproductive inactivity, although hypothalamic,
pituitary, and ovarian hormonal fluctuations are occurring.
During anestrus, the uterus is undergoing recovery and
repair following a false or true pregnancy. The normal bitch
is neither attractive nor receptive to male dogs. Little
vaginal discharge is present, and the vulva is relatively
small.
Vaginal cytology taken during anestrus finds small
“parabasal” cells, with occasional white blood cells and
small numbers of mixed bacteria representing normal flora.
Anestrus normally lasts from one to six months, before the
bitch enters proestrus again and starts another heat cycle.
At least two months of anestrus are required for fertility.
Carolyn Russell Gold is the Gordon Setter columnist for
the AKC Gazette.This article first appeared in two
installments in the Gazette’s 2013 April and July
issues.
|