- Relaxin is thought to be important in relaxation
of the soft tissues around the pelvis. Detectable after 25 days of
gestation relaxin from the fetal-placental unit declines abruptly
- Prolactin from the anterior pituitary increases
at day 35 and peaks at about day 50 of gestation to term.
Prolactin is important for mammary development, evident around
24-48 hours before parturition, and subsequent lactation.
- Estradiol concentrations are variable during
pregnancy but the concentration surges about 9 days before
- It is theorized that initiation of parturition in
the queen is similar to that documented in the ewe. An initial
fetal cortisol rise alters placental progesterone production into
estrogen. The estrogen causes a release of prepartum
prostaglandin. The prostaglandin, or the abrupt decline in
progesterone, may have a hypothermic effect on the queen; an
effect observed in a drop of the rectal temperature of the queen
during the first stage of labor.
- The queen can control parturition to some extent,
therefore it is important that the queen be in a secluded,
comfortable area for queening. Provision of a queening or nesting
box 7 days prepartum will give the queen familiar surroundings for
parturition. She may be placed in total isolation, in a prepared
queening box, in an area of the queen's choosing, or in the
company of a trusted human companion.
- Parturition may last as long as 24-36 hours, but
kittens are usually expelled after a mild labor of 30-60 minutes
and a 5-10 minute period of intense labor. After the birth of a
single kitten, the queen may not exhibit signs of labor for 30-120
minutes. Usually each individual placenta is passed after each
kitten or it may be passed after a subsequent kitten. The queen
commonly ingests the placenta and then cleans the kittens.
Abnormal Parturition (Dystocia)
- Dystocia is not normally a problem in the
healthy, physically conditioned queen.
- Dystocia is most commonly associated with the
birth of the first kitten.
- After delivery of the first kitten, parturition
usually proceeds normally.
- Diagnosis of dystocia can be based upon any of
the following observations during queening:
- 1) 20 minutes of intense labor without a kitten
- 2) 10 minutes of intense labor when a kitten is
visible in the birth canal;
- 3) acute depression;
- 4) elevation of body temperature; or
- 5) the presence of fresh blood for more than 10
Maternal vs fetal
- When a dystocia is diagnosed, it is important to
differentiate between a fetal and maternal dystocia in order to
proceed with the correct therapeutic measures.
- Fetal dystocias are caused by oversized or
malpositioned fetuses in the uterus or birth canal.
- Maternal dystocias are caused by failures of the
queen to pass normal sized kittens.
- Maternal dystocias include uterine inertia, small
pelvic diameter, uterine torsion, uterine rupture and ectopic
- Fetal dystocia can usually be corrected if the
kitten can be palpated per vaginum by liberally applying
lubricant, and allowing the queen to continue with parturition.
- Cleanliness is essential when entering the birth
canal, because introduction of bacteria into the uterus during
manipulations can be a major cause of postparturient metritis.
- If the kitten cannot be palpated per vaginum, it
is best to radiograph the queen to determine the kittens' position
and relative size.
- Very small litters tend to have larger, oversized
kittens that cause dystocia. In these cases, cesarean section is
the preferred method to correct the dystocia since excessive
manipulation or use of instruments harm the kittens and queen.
- Maternal dystocias are most commonly caused by
uterine inertia. Uterine inertia occurs when the birth process has
exhausted the uterine musculature making contractions impossible
- non rhythmic (secondary uterine inertia). It can
also occur when the uterine musculature has insufficient
uterotonic stimulation from oxytocin (primary uterine inertia).
- Uterine inertia can be treated by administration
of oxytocin at a dosage of 2-4 IU IM every 20 minutes. If oxytocin
fails, 1-2 ml of 10% calcium gluconate solution can be
- slowly intravenously.
section should be considered the best
option for saving the litter if these efforts fail.
- Because the duration of normal parturition may be
up to 24 hours, determining exactly when a queen is experiencing
dystocia may be difficult. It must be remembered however, that
normal parturition can be prolonged and that placing a queen in a
secluded queening area may be the best option for the queen and
the client. Because the queen can voluntarily control parturition,
excessive intervention by humans can actually prolong the length
of parturition or delay its onset.
- If the queen has signs of acute depression,
elevation of body temperature or fresh blood coming from the
vagina; uterine torsion, uterine rupture, or ectopic pregnancies
should be considered. Although these are uncommon signs, upon
seeing them, the dystocia is best handled via
to maximize the queens chances for survival.