Care of the Brood Bitch
February, 1996
Dealing with canine reproduction can be a challenging and
rewarding experience. Breeding, pregnancy and whelping can
frequently take place with a minimal amount of and no veterinary
intervention. However, these events are not always routine, and
the breeding of female dogs should only be attempted by
individuals who are willing to put in extra time and effort in
caring for brood bitches and to learn all they can about canine
reproduction. All other females should be spayed when young to
help prevent such common problems as mammary tumors and uterine
infections.
Conscientious breeders will breed only bitches who have shown no
signs of heritable disease and have highly desirable traits in
such characteristics as temperament, physical appearance or
hunting ability.
Normal beagles may go through their first heat cycle as early as
six months, or as late as one and a half years of age. They
repeat the cycle every six to seven months. It is best to wait
till the second or third heat before breeding a young female for
the first time. They tend to have less problems and you get an
idea of what the heat cycle will be for that particular dog.
The bitch should be brought to the veterinarian for a
pre-breeding exam to check for infectious disease (including
Brucellosis, which is venereally transmitted) and internal
parasites, and to make sure she is properly vaccinated as she
will pass on this immunity to her pups.
To decide when to breed, it is helpful to have some knowledge of
canine reproductive physiology. Proestrus is the stage of the
bitch’s cycle during which one sees vaginal bleeding, an
enlargement of the vulva, an attraction by males; but the bitch
will not allow mating. Proestrus
usually lasts 6 to 11 days. This is followed by estrus, or
standing heat, which lasts 5 to 9 days. The first day the bitch
will allow breeding is the start of estrus and this stage ends
when she will no longer accept the male. Ovulation occurs in the
middle or end of estrus, and the female’s eggs take one to
two days to be ready for fertilization. The simplest breeding
tactic involves “teasing” the bitch with any male dog
on day 5 or 6 of Proestrus and repeating the procedure every two
to three days until the first day of estrus is determined. Then
allow the bitch to be bred on her first day of acceptance and
continue to breed every second or third day until the end of
estrus.
Some breeders worry that this will lead to fetuses of vastly
different ages in one litter, but this is not the case. All of
the bitches eggs are released from the ovary over a 24 - 72 hour
period, and all will be fertilized over the same time frame, even
if the breeding occurred over a nine or ten day period.
The most common cause for failure to conceive is poor timing. For
these “problem” bitches, your veterinarian can examine
cells obtained from vaginal swabs to help determine what phase of
the estrous cycle the bitch is in. This is most informative if
done every other day, starting on the fourth or fifth day of
Proestrus. A more accurate determination of the time of ovulation
is possible if blood progesterone level is checked. A sudden
increase in progesterone will occur two to three days before
ovulation starts.
Artificial insemination (A!) may be useful if the bitch is
cycling normally and the male is capable of achieving ejaculation
but other factors prevent natural mating. This is probably best
accomplished at the veterinarian’s office, where the doctor
and staff collect the male’s
semen and, using sterile technique, deposit it into the female’s
reproductive tract. Frozen semen can also be used, if
transportation of one dog to the other is impractical. Conception
rates following Al are lower than those seen with natural mating.
Therefore, AI should be reserved for those cases where natural
breeding can not be achieved.
The normal pregnancy or gestation period lasts about 63 days.
Pregnancy can be detected as early as three or four weeks with
ultrasound examination. You veterinarian may also be able to
palpate fetuses at that stage, but this is a less reliable method
of detection. Radiographs (x-rays) will not show fetal skeletons
until 45 -50 days into gestation. It may be helpful to know the
exact number of puppies to expect at whelping time, so x-rays are
still considered a useful tool.
In the last two weeks of pregnancy, the bitch should be provided
with an area for whelping and nursing her pups. Many breeders
build a whelping box to meet certain criteria. It should be large
enough for the bitch to be down and still have room for a litter
of puppies. The sides should be high enough so that four to five
week old puppies can not jump out. The wall of the box should
have a ledge near the floor to prevent a bitch that is lying down
from crushing a puppy between her and the wall. The ideal
temperature for the box floor would be about 75 degrees F, which
can be accomplished with ordinary light bulbs.
The diet for a pregnant bitch should consist primarily or totally
of a high-quality commercial dog food. A diet balanced for
feeding puppies will meet her increased demand for energy,
protein and minerals. The amount fed may be gradually increased
during pregnancy, so that she may be consuming 1 1/2 times as
much at the end of pregnancy as she was at the beginning.
(Two-thirds of the growth of the fetus occurs in the last
onethird of pregnancy). Calcium and other mineral supplements
should not be added to the diet already mentioned for normal
pregnant bitches. Those that have had eclampsia (caused by low
blood calcium) after previous litters may benefit from calcium
supplements given in the last week of gestation and throughout
lactation.
When unplanned matings occur, there are drugs capable of
preventing or terminating pregnancy, but none are considered very
safe. Therefore, it is important to make sure you know when each
bitch is due to come into season and prevent “mismating,”
rather than risk the dog’s health with hormone treatments.
Likewise, contraceptive medications are available that prevent a
bitch from going through Proestrus and estrus, in order to
accommodate her owner’s schedule. However, such agents have
limitations, they can not be used for long time periods, they may
affect behavior and activity levels and are not recommended for
use in brood bitches.
A future article will deal with whelping and the care of newborn
puppies.