All breeders have one fear at whelping time – dystocia. Although you can’t prevent all causes of puppies having difficulty passing through the pelvic canal, you can render some assistance. To do this, you need to know what to expect in a normal whelping. It will help alleviate some anxiety; it may even mean avoiding a needless visit to the veterinary hospital.

It all starts with knowing when whelping will occur and this is done by using a combination of breeding dates and hormone measurements.

Determining the due date
Gestation lasts for 57 to 72 days (the average is 65) from breeding. This range exists because sperm can remain viable in the uterus for at least six days after coitus.

Blood tests are more precise in determining whelping day, which occurs 63 days after ovulation and 64 to 66 days after the luteinizing hormone (LH) peak.

Ovulation can be tracked through progesterone blood tests. Another option is vaginal cytology. LH levels tend to be used only in research settings.

The length of gestation is partly influenced by the number of puppies in the uterus – it shortens as litter size increases and lengthens with smaller litters. This is because the fetuses initiate the whelping by releasing steroids that, through a complicated cascade of hormones, ultimately cause uterine contractions. There is no difference in gestation length between a bitch’s first and her subsequent litters.

As labour starts, the bitch becomes restless, loses her appetite and prepares a place to have her puppies (nesting behaviour). As well, there is significant swelling of her mammary glands, and production of milk.

Many breeders use body temperature to warn of impending labour. A drop of over a full Fahrenheit de-gree (.5 Celsius degree) indicates parturition will occur within 12 to 24 hours. Start taking the bitch’s rectal tem-perature on the 57th day after breeding, and do it three times a day. This gives you a baseline and you won’t miss the drop.

Normal labour and delivery
During Stage I labour – the first part of whelping – the uterus contracts and the cervix progressively dilates. Stage I usually lasts six to 12 hours, but in a first whelping, it can be up to 24 hours. Panting and restlessness mark this stage, but there is little else to see.

Stage II labour starts when strong abdominal straining matches the uterine contractions and there is active expulsion of the fetus from the birth canal. The first fe-tus is usually delivered within 30 minutes of the first visible contractions, but it can take two to four hours. Stage II should be complete within 12 to 24 hours, with puppies delivered every 30 minutes to four hours.

Stage III labour is the expulsion of the placenta, taking place five to 15 minutes after delivery of the fetus. Multiple placentas can be passed if several puppies are delivered close together.

Many bitches sever the umbilical cord and eat the placenta. Some breeders encourage this as it supposedly creates better puppy bonding, but they let the bitch eat only one or two so she doesn’t get indigestion. Others let the bitch do what comes naturally.

After parturition, bitches may have a fever as well as transient vomiting and diarrhea. A green to red-brown, odourless vaginal discharge can persist for up to six weeks and is associated with involution (shrinkage) of the uterus. Suspect a problem if an odour develops or the discharge changes character.

How to recognize dystocia
Dystocia is caused either by the bitch (maternal) or the puppies (fetal). The most common cause is uterine iner-tia – lack of uterine muscle contractions – a maternal problem. The cause is rarely determined, but the result is the same – puppies can’t be delivered.

About 60 per cent of puppies are delivered headfirst. A tail-first presentation has no bearing on the incidence of dystocia and is considered normal. Some breeders mistakenly call a tail-first presentation a “breech.” A breech puppy is one that lies between both uterine horns and fails to enter the birth canal.

Fetuses that are oversized, malformed or dead, as well as those oriented the wrong way (malpresented) account for most cases of fetal dystocia. This can be di-agnosed only with a radiograph.

The table on page 30 provides guidelines on when it is appropriate to call your veterinarian. However, there are some things you can do at home to evaluate the situation and possibly assist the bitch.

First, examine the mammary glands for the presence of milk to confirm it’s close to whelping time. You may need to do a vaginal examination. Start by clipping the long hair around the vulva and clean the area with a mild antibacterial soap.

To do an exam, use sterile gloves. Insert a lubricated finger (e.g., K-Y® Jelly) and see if there is a puppy present. If there is, the bitch is in Stage II labour. If there is no puppy, insert the finger farther to see if the cervix is dilated. If there is no constriction and your finger can go in fully, the cervix is open. In this case, there should be a puppy present. If there isn’t, you’ve got a problem. Call for help.

If there is a puppy, try stroking the upper (dorsal) vaginal wall. This “feathering” normally stimulates strong uterine and abdominal contractions. A lack of response indicates uterine inertia, the bitch is not in labour, or she is overly stressed or excited. Again, help is needed to figure out what is going on.

If she starts to contract and a puppy is progressively moving through the canal, watch to see if the puppy can be delivered. If the bitch is pushing but not making any progress, it’s time for a hospital visit.

Medical or surgical intervention
The first thing your veterinarian will do is take a radiograph to see what’s going on. It may reveal a malpositioned puppy, or an obstruction in the pelvic canal (tumour or healed fracture). It also gives an accurate indication of the number of puppies.

If there is a fetus in the pelvic canal and there are abdominal as well as uterine contractions, the veterinarian may try managing it medically. Giving the hormone oxytocin is an effective way to augment labour. Research shows that oxytocin (medical management) helps about one-third of bitches. The other two-thirds in dystocia require a Caesarean.

A Caesarean should be done if there is uterine inertia, an obstruction in the pelvic canal, fetal malposition, fetal death, a large (oversized) fetus, or if the veterinarian measures a fetal heartrate of fewer than 150 beats per minute (this suggests fetal stress).

The anaesthetic used and the surgical technique em-ployed depends on what the veterinarian is comfortable with. However, with the newer anaesthetics, Caesareans are safer than ever before.

Regardless of the technique (medical or surgical), there is a significant neonatal mortality in puppies af-ter the delivery. Those delivered by Caesarean section generally have eight-per-cent mortality at birth, 13-per-cent two hours later, and 20-per-cent by seven days. Those delivered naturally have 14-, 17- and 25-per-cent in the same intervals. Mortality of bitches undergoing Caeserean is reported as about one per cent.

When whelping time comes around, learn what to expect and be prepared. Accurate identification of dystocia and the patient’s stage of labour help reduce the overall fetal mortality rate.
1.     Prolonged gestation – due date reached with no signs of whelping
2.     Temperature drop (below 99.7°F or 37.6°C) for 12 to 24 hours without the onset of labour
3.     Temperature drops, then increases (greater than 102.5°F or 39.2°C) for more than 12 hours
4.     Vaginal discharge for more than three hours
5.     Lack of progression to Stage II labour after six to eight hours
6.     Strong, active abdominal contractions for more than 30 minutes without expulsion of a puppy
7.     Stage II labour lasting more than 12 hours
8.     Membranes or part of a fetus protruding from the vagina
9.     Signs of an ill bitch

By Jeff Grognet

A multi-published writer, Jeff Grognet, D.V.M., B.S.c.(Agr.), runs a veterinary practice in Qualicum Beach, B.C., along with his wife, Louise Janes, D.V.M.

(Originally published in our October 2008 issue. To learn more about our print edition click here)