Puppy absorption happens when a pregnant female dog has one or several foetuses disintegrate in her uterus following an infection or another type of pregnancy problem. Foetal resorption in dogs can only happen in the weeks of the pregnancy when the tissues are soft and bones are not properly formed.
Types of pregnancy loss.
Abortion – Defined as the expulsion of foetuses before full term pregnancy. Abortion is uncommon in the bitch. Reabsorption or Mummification is more common.
Mummification – The death of foetuses after the calcification of the skeleton (usually by day 50 in the dog) may often lead to the mummification of foetuses. The foetuses are maintained within the uterus, and degradation occurs to a certain extent, but the skin dries around the foetus forming a membrane that may delay complete foetal decay and reabsorption for prolonger periods of time. Mummified foetuses may be retained in the uterus, and the general health of the dam is not affected. The skull and skeletal parts are also intact, and the foetus remains more or less recognisable in the uterus by ultrasonography or radiography.
Premature Birth & Stillborn Puppies – The expulsion of foetuses after the foetus is capable of independent life. Stillborn puppies are full term foetuses that are born dead. Death may occur a few days, hours or minutes before parturition (birth). Infections, intoxications, dysfunctional placentas, inadequate uterine space, dystocia, malformations and luteal failure are some causes responsible.
Reabsorption – Generally foetuses will normally only be reabsorbed if they die during the first half of pregnancy. Incomplete reabsorption is possible as well as reabsorption of a few foetuses, while others develop to full term. The most common causes are inadequate hormonal support, endometrial or placental disorders or intoxications and infections, such as canine herpes virus or brucellosis. There follows a more in depth look at reabsorption in the bitch.
Although this is scary and worrisome for dog breeders, canine foetal resorption seems to happen in 11% of all dog pregnancies. It often happens so early in the pregnancy that it is unnoticed. Generally, absorbed puppies cause no complications to the mother dog.
What Is Puppy Absorption?
Commonly termed in the medical field as canine foetal resorption, a puppy absorption is a biochemical process in which the tissues of a live foetal organism, in this case, the puppy, begins to deteriorate and decompose. This is a process of disintegration of the enzymes in the foetus when it’s still inside the womb that allows for a complete obliteration of the organism resulting in total reabsorption. Foetal absorption is not to be mistaken with embryo loss in which the embryo is reabsorbed during an earlier stage of gestation.
As a rule, after a certain amount of days (44 days roughly), puppy absorption cannot be performed because of the development of the skeletal bones, those of which cannot be reabsorbed. For this reason, a canine reabsorption can only occur during the earlier stages of pregnancy when the foetus is made up of mostly soft tissues.
Most puppy absorptions happen to only one or two puppies in the litter. Yet, it may occur that an entire litter of puppies gets absorbed.
Unlike a miscarriage, the foetus does not leave the dam’s body after death. During foetal resorption, the dam’s body begins to absorb the placental tissue, followed by the actual foetus itself. The puppy that has been reabsorbed literally disappears from the litter and uterus. The puppy’s body dissolves in the natural chemical process and often causes much confusion to outsiders who are not familiar with this term.
This systematic approach in the dam’s body actually works as an advantage to her as it is dangerous to abort a foetus within a litter if the other pups survive and make it through the birthing process successfully. The act of absorption eliminates the risk of anything unsettling happening to the mum during the remaining of the pregnancy, and at delivery.
As daunting as this all may seem, especially for an unsuspecting dog owner, this phenomenon is actually quite common and is a normal part of the natural processes of canine reproduction and living. According to various studies, on average, about 11% of canines experience foetal resorption.
Causes of Foetal Resorption in Dogs
There are a number of reasons that could qualify as a legitimate cause for puppy absorption. Some believe, because of its natural occurrence, it may be nature’s way of preserving the dead or protecting the mother as a survival mechanism. In either case, it may be essential to take note of the time of reabsorption as a helpful indicator of why it happened in the first place.
The leading causes of puppy absorption tend to vary from dog to dog depending on many factors. Most times, the dog’s owner is unaware of reabsorption because the process can oftentimes go unnoticed. A puppy can reabsorb before the owners are even aware that the dam is pregnant and, in such cases, unfortunately, a cause can never be determined. In the event that the reabsorbed puppy was detected and confirmed alive and later confirmed dead, coinciding events and the status of the other pups can help establish a logical reason for the resorption. Some absorptions can be caused by infectious agents and others caused by non-infectious agents.
- Brucella Canis— Commonly referred to as Brucellosis, the Brucella Canis bacterium can cause infection in the dam by affecting her reproductive organs and is even considered to be highly contagious. Brucellosis is responsible for a number of stillborn pups in many dogs of all ages and has been known to even cause infertility.
- E Coli— Escherichia coli is a very common bacteria found in a canine’s bloodstream that causes the disease known as colibacillosis. Taking preventative measures in pregnant canines goes a long way in avoiding this condition. Owners of pregnant dams are advised to give adequate nutrition to her as well as keep her in highly sanitary conditions. Other bacterial agents that can cause reabsorption are Streptococcus spp. and Staphylococcus aureus.
- Canine Herpesvirus— This canine virus belongs to the Herpesviridae family and is most commonly referred to as the virus that causes fatal haemorrhaging. In fact, it’s a documented fact that this disease is the leading cause of foetal deaths in puppies. The most unfortunate aspect of this virus is its 100% mortality rate for the affected puppy litters.
- Parasites— This parasite causes an infection called toxoplasmosis. These parasites are known to reside in the faeces of cats and other times in the roots of contaminated soil or even unwashed fruits and vegetables.
- Genetics— The genetics of the pups can play a role in whether or not the foetus will be properly developed. Some genetics may cause malformations or even not allow full development to occur to allow survival, thus allowing for reabsorption.
- Drugs— There are certain drugs that are given to dams that may affect the developmental stages of the whelp. It is possible that an adverse drug reaction may have been the cause of any of the pups in the litter to reabsorb.
- Nutritional— All mothers, whether canine or human, require sufficient nutrition to withstand a pregnancy. The nutrition of the mother affects the babies and therefore, any malnutrition can cause early death in the foetus.
- Developmental/Chromosomal Defects— Any anomaly or defect found in any of the developmental stages can result in early death to a canine foetus. Chromosomes assist in the development and growth of the cells and sometimes even breeding the canines at inappropriate times can lead to defects. Sperm and egg cells, as a result of this, may deplete or lose all function leading to eventual death.
- Hypothyroidism— Certain endocrine disorders such as hypothyroidism can warrant unwanted effects on the foetus of a canine often leading to aborted foetuses.
- Placental or Uterine Anomalies— The placenta and the uterus of the pregnant mother are the main organs that allow for a successful birth, so any disruption in the formation of the foetus can lead to some serious risks and even death.
- Hormones— This seems to be one of the most common causes of foetal absorption in puppies. Adequate hormones are needed to develop ideal conditions in the dam’s body for reproduction and development of the foetuses to occur naturally.
- Environmental Stresses— Stress can wreak havoc on the body especially during pregnancy. If any environmental stresses become too unbearable the body can begin to stop functioning at its optimum level and thus, lead to various complications which may lead to foetal resorption.
Younger female dogs and first-time canine mothers tend to be more at risk with puppy absorption.
Can a Female Dog Absorb an Entire Litter?
Although the majority of canine foetal resorptions occurrences often happen to only one or two puppies in the litter, it is possible that a female dog absorbs her entire litter as well. There have been some instances in which some dogs have looked pregnant and all the sudden, no longer have their bellies. That could be a sign where the dam has lost all of her pups due to absorption.
The same reasons that cause one of the foetuses to reabsorb also applies to the entire litter. Diseases and malnutrition to the dam can cause an array of issues that result in the loss of her pups if all of them become affected and thus, too weak to cope. It is also possible that infectious agents such as bacteria and viruses may pass on to all the foetuses and result in a spontaneous litter absorption. Unfortunately, in these cases in which all puppies are reabsorbed, a lack of sufficient information results in unanswered questions. Because there are no survivors in an absorbed litter, there is no way to make comparisons with other puppies that will help indicate a cause.