Fetal and uterine monitoring services for veterinarians: Veterinary Perinatal Specialties,
The type of treatment is dictated by the presence or absence of obstruction and by the health of the dam and fetuses. In addition
to maternal survival, the goal of managing dystocia is to achieve puppy and kitten survival beyond the most critical first
week of life. A partially delivered fetus should be delivered within 10 minutes. If obstruction or serious fetal compromise
exists, Caesarean section is indicated without delay. If no obstruction exists, medical management may be attempted in healthy
dams with no signs of fetal stress.
In situations were the dam and the fetuses are healthy, and no obstruction exists, medical management of dystocia can be considered.
The goal of medical management is to re-establish a normal labor pattern of uterine contractions. This is done with oxytocin
and calcium. Typically, oxytocin increases the frequency of uterine contractions and calcium increases the strength. High
doses and/or frequent administration of oxytocin are contraindicated because they cause sustained uterine contractions that
delay the expulsion of fetuses and compromise placental blood flow. Current recommendations are to administer small doses,
0.25 to 4.0 U per dog, intramuscularly (IM). Labor should progress (i.e., straining begins) within 30 minutes and a pup should
soon be delivered. If so, the clinician may repeat administration of oxytocin as needed to perpetuate normal parturition.
Repeated doses should not be administered if a normal labor pattern is not established.
Generally speaking, calcium administration increases the strength of uterine contractions even in the absence of documented
hypocalcemia. For this reason, some have recommended the routine administration of calcium gluconate in the management of
non-obstructive. Calcium gluconate, 0.2 ml/kg or less, or 1 to 5 ml/dog, is administered subcutaneously (SC) or intravenously
(IV), depending on the preparation and the label directions. Some preparations are too irritating to be administered by routes
other than IV. If the IV route is chosen, calcium is administered slowly (1 ml/min), while ausculting the heart. Administration
should be immediately discontinued if bradycardia or dysrhythmia occurs. Higher doses or bolus IV administration of Ca gluconate
should be reserved for animals with documented clinical signs or laboratory evidence of hypocalcemia. When medical management
fails to initiate a normal labor pattern, Caesarean section should be performed.
Caesarean section is indicated, without delay, in the following circumstances: obstruction, such as fetal oversize, fetal
malposition, or uterine torsion; fetal compromise exists; medical management with calcium/oxytocin administration has failed;
continued pregnancy or labor might be harmful to the dam; or maternal illness already exists.
Embryonic and fetal death can result from maternal disorders, fetal disorders or placental disorders. Queens and bitches often
lose one or more fetuses and yet carry the rest of the litter to term and deliver normal healthy puppies or kittens. Anything
that adversely affects the health of the dam, and medications used to treat her, have the potential to adversely affect the
pregnancy. Other than a disorder that causes overt clinical illness in the dam, the signs associated with fetal death depend
primarily on the stage of gestation at which the loss occurs.
When early embryonic death occurs, there are no clinical signs of the bitch having been pregnant. Therefore, she is likely
to be presented for (apparent) failure to conceive rather than for pregnancy loss. In queens, having been induced to ovulate
by the fertile mating, early embryonic death will be reflected by a prolonged interestrual interval of 30 to 50 days, rather
than the usual non-ovulatory cycles every 14-21 days. Pregnancy loss has no effect on the canine interestrual interval. Usually
there are no physical signs, such as vulvar discharge, when embryonic death occurs during the first 30 days of gestation in
bitches and queens. Resorption occurs. When fetal death occurs after about day 30 of pregnancy, uterine contents are passed (abortion). The first clinical
sign of abortion is usually a blood-tinged vulvar discharge. The character of the discharge is variable, according to the underlying cause
of the abortion. The quantity is variable from scant to substantial. The later in gestation fetal death occurs, the more obvious
it becomes that fetal parts are being expelled.