Heart Rate Doppler
equipment has been used in human medicine for over 20 years to confirm
pregnancy and document the ongoing development and well-being of the fetus.
The ultrasound doppler can also be used in veterinary obstetrics to
confirm pregnancy and monitor the developing fetuses in all small mammals.
Use of ultrasound to detect fetal heart rates in canine and feline
reproduction is becoming standard of practice for both the veterinarian and
Fetal heart rates are detectable around 5 weeks of gestation using the
hand-held Elite doppler in dogs and cats. The doppler detects the motion of
the beating heart; translating the motion into an audible heart beat, and
digitally displayed heart rate. Using
the doppler throughout gestation allows the veterinarian or breeder to confirm
pregnancy, determine the number of fetuses in the litter, as well as document
their continued survival. Monitoring
fetal heart rates during the Whelping or Queening process will allow the
breeder or veterinarian to detect fetuses that are stressed by the labor and
may not survive.
number of fetuses in each pregnancy is accomplished by geographical
identification of each individual fetal heart rate.
Litter size is established by systematic examination of each side of
the abdomen using the doppler equipment to detect individual heart rates.
In order to facilitate ultrasound penetration, the lower abdominal area
must be clipped to the skin to remove all hair.
The litter size can be determined with very good accuracy by adding up
the number of fetal heart rates detected on each side of the abdomen for a
total number of fetuses. Using
the doppler to determine litter size may eliminate the need to do a routine
X-ray. The use of X-ray can be
used as a secondary level of evaluation.
Is it possible
to be incorrect on the litter size using the doppler? The answer is yes.
Is it possible to be wrong on a fetal count with an x-ray or visual
ultrasound? The answer is also
yes. Can you perform an x-ray or
visual ultrasound in the home? Not likely in most cases!
The small, easy to use design of the doppler makes it perfect for home
or clinic use. Home use allows
the breeder to monitor fetal heart rates during deliveries, confirming the
number of fetuses detected during the pre-labor screen.
A second benefit
of fetal heart rate monitoring during labor is documentation of fetal
well-being. Systematic fetal
heart rate monitoring in most cases will alert the breeder or veterinarian to
fetuses not likely to survive through delivery.
Fetuses that are under stress from labor have specific variations to
the normal fetal heart rate. These
variances are easily identifiable by the novice ultrasound user.
Early identification of problems will allow the breeder or veterinarian
the opportunity to intervene with either the appropriate medication or a
cesarean section before puppies or kittens are lost.