This week was one of those weeks where I encountered the two extremes of canine pregnancy. The first case was that of a cross breed which went through a normal labour and gave birth to eight lovely puppies. The second happened with an Alaskan malamute during the actual birth, which did not go so well. Together, the medical cases served as a reminder of the dichotomy, or opposite conditions, of the canine birthing process – labour and dystocia.
As with all mammals, pregnancy in dogs is a complex medical condition that can present risks for both mother and puppy. The culmination of the pregnancy is the labour, which is when the puppies are born without complications.
There are three major stages of labour. An ideal normal birth starts with the rupture of the first puppy’s chorioallantoic sac and the ammoniac fluid flows out, lubricating the area. By now the mother’s cervix would have relaxed in preparation for the birthing, and her uterus starts to contract to aid the pushing of the puppies down the birth canal.
During this time, the bitch may occupy herself by preparing a nest for her puppies – either by rearranging her bedding or by retreating to a private corner in the house. She may also be restless or seem anxious. During the second stage, the uterine contractions start to push the unborn puppies down the birth canal and the bitch prepares to give birth. On average, it can take up to three hours for the first puppy to show; after that, any remaining puppies will usually come in half-hour to one-hour intervals. The placenta of each puppy may be expelled after each birth or in batches after every two or three puppies. But sometimes, things do not go well during labour, and this is when the process of birth is described as dystocia.
There are various reasons as to why things may go wrong during the birthing process. Sometimes, it happens due to factors related to the as-yet unborn puppies. For example, one or more of the puppies inside the mother may not be positioned correctly for the time of birth. One of the puppies might be unusually large and prevent itself or other puppies further up the uterus from being born. Occasionally, one or more puppies might be malformed or dead inside the uterus and they compromise the labour.
Sometimes, things do not go well during labour, and this is when the process of birth is described as dystocia
Dystocia might also happen because of maternal factors. For example, a fairly common cause is when the uterus remains sluggish. This is referred to as uterine inertia and may occur in one of two forms: primary and secondary. Primary inertia happens when the mother does not start her contractions when she is supposed to; secondary inertia is when the uterus stops contracting mid-labour. The latter condition usually occurs when the labour is prolonged and the mother gets so tired that her uterine muscles can no longer contract strongly enough to ensure a successful birth.
The age of the dog is also an important factor to consider – the older the female dog, the harder it becomes for her to deliver successfully. Brachycephalic breeds such as pugs, bulldogs and boxers, and toy breeds such as chihuahuas are also predisposed to have a difficult labour. It’s worth noting that a dog that has already suffered dystocia is likely to suffer a repeat the next time she is pregnant.
Owners of pregnant dogs can sometimes be the unwitting cause of dystocia as, for example, when they overdose their pregnant dogs on nutritional supplements in a misguided attempt to do the best for their dog.
Obesity is another problem that increases the likelihood of problems occurring during delivery, for example because of hypertension, that is, high blood pressure. Dogs that are overfed are also at risk of nutritional imbalances with a high-risk of becoming hypo-glycaemic, that is, suffering from low blood sugar levels.
Although not technically classified as a dystocia, there are cases where the mothering dog spontaneously aborts her puppies, and the cause is sometimes due to bacterial or viral infection. For example, B.canis is a bacteria that can bring about reabsorption of the tiny embryo very early during pregnancy or abortion of the foetuses quite late in the gestation period, besides causing infertility.
A virus that similarly brings about abortion in the dog is the canine herpesvirus. Puppies infected inside the womb and that make it full-term are usually born malformed or dead. The impact of an abortion on the dog can depend on how advanced the pregnancy is. If it is early enough in the pregnancy, she may take in her stride with little to show for it other than the physical evidence of the abortion. The abortion may also happen in stages or all at once. Abortions that happen later in the pregnancy, when the mother has already started to prepare herself for motherhood, may have more of a negative bearing on the dog and the loss of the puppies can have a devastating effect on the bitch as well as her owners.
The bottom-line is that if you have a pregnant dog, you should take her to your vet for regular check-ups. If you are planning to mate your dog, you should speak to your vet at least a full month beforehand to be able to discuss first of all whether a pregnancy is indicated, how it is possible to know when is the best time for mating to have a successful pregnancy, when pregnancy can be confirmed and all the preparations necessary for the big day.
Breeding your pet dog is a decision that should be given careful consideration by all the family. When it goes well, it is usually a joyful event but it can still require a lot of work. When it does not go well, it can be heart-breaking but, with the help of your vet, you will find yourself better prepared in case of need.
Dr Martin Debattista is a veterinary surgeon.
thisweekwiththevet@gmail.com