Miscarriage is the death of unborn puppies during a dog’s pregnancy. Pregnancy loss can occur at any time during the dog’s pregnancy, and can affect one, a few or all of the unborn pups.
There are multiple underlying causes of miscarriage in dogs including bacterial or viral infections, parasites, hormonal changes, trauma or even genetic conditions.
Understandably it can be a sad and confusing time for owners, especially if the pups were planned and highly anticipated, and the miscarriage happens later in the pregnancy.
It is also often a distressing time for the mother dog, who may act strangely or out of character. This article will clear up any myths, and provide you with all the information you need to know about miscarriage in dogs.
What is a Miscarriage?
A fetus is an unborn, developing pup. Miscarriage is when there is a death of one or more of the fetuses inside a dog’s womb. Pregnancy loss can occur at any time during a dog’s pregnancy, from conception until full term (usually around 63-65 days).
If miscarriage occurs in the early stages of pregnancy, then the mum dog usually absorbs the developing fetus back into her body, leaving no trace of the pup behind.
Later in the pregnancy, a miscarriage will result in the dead fetus(es) being expelled from the birth canal, which may be accompanied with significant bleeding.
She may lick and eat the evidence of a miscarriage, therefore it is important to closely monitor your pregnant dog for any abnormal vaginal discharge, excessive licking or change in behavior.
If you think your pregnant dog might be showing any signs of miscarriage, then it is important that she is checked over by a veterinarian. They will be able to confirm if the pregnancy is lost, or try to save any remaining pups.
Obviously, the health of the mum dog is also very important. Some causes of canine miscarriage may put the mum’s health at risk too, so the veterinarian will be able to ensure the bitch is ok and provide any necessary treatment.
Types of Pregnancy Loss in the Dog
Miscarriage can happen at any time during a dog’s pregnancy, and can be due to numerous underlying causes. There are different types of pregnancy loss in the dog, and each occur at a different period of development of the unborn puppies. Let’s look at each one in a little more detail.
If pregnancy loss occurs in the first half of the pregnancy, then fetal reabsorption usually occurs. Due to an underlying problem, the tiny developing fetus disintegrates and is absorbed by the mother’s womb, it just vanishes.
The mum may reabsorb one or sometimes all of the developing fetuses back into her body and there are often no outward signs of the miscarriage. Reabsorption can’t happen after day 45 as the hard skeletal bones of the fetus which are developing from that time cannot be reabsorbed.
It may come as a surprise but studies have shown that around 10-15% of developing canine fetuses are reabsorbed, with the mum dog showing no signs at all.
Abortion is when the unborn pup leaves the uterus before full term, and before it can survive outside the womb. Obviously some owners may go to a vet clinic and request their dog have an induced medical abortion if the dog’s pregnancy wasn’t planned.
However, if the dog’s abortion suddenly occurs without intervention it is known as a miscarriage or spontaneous abortion. Thankfully spontaneous abortion is not very common in the dog. Fetal reabsorption or mummification is more common.
If there is a death of an unborn fetus after the skeleton develops (around day 50) then the fetus may become mummified. This crazy phenomenon may sound like something from a movie, but it occurs in lots of mammal domestic species.
The dead fetus becomes very dry, walled off and preserved within the womb. This may affect one, a few, or all of the pups, and is often due to canine herpes virus (CHV) infection.
Mummification of dead puppies may cause the mum dog to have problems giving birth to any remaining normal pups present, as the uterus may not contract in the normal, strong way. Therefore, a caesarean may be necessary to successfully remove both the mummified fetus(es) and normal foetuses when the time comes.
Stillborn puppies are those that are born dead at the end of the pregnancy term, when they are fully developed and ready to survive outside the womb. Stillborn death may happen a few days, hours or minutes before the birth is due.
Signs of Miscarriage in Dogs
The signs of miscarriage depend on the stage and development of the fetus. If the miscarriage occurs in early pregnancy, then the dog usually resorbs the tiny developing fetus(es), and often shows no signs at all.
As a veterinarian I have had a case where I confirmed a dog was pregnant in an early ultrasound scan, then a few weeks later the ultrasound scan showed no pregnancy at all- it can be heart breaking for an owner to hear the pregnancy has just vanished!
Later term miscarriages are usually associated with more clinical signs including:
Every pregnant dog needs to be closely monitored for any change in behavior or health. Sometimes the signs of miscarriage may be subtle and easily missed, especially if the dog cleans and licks her vulva a lot, or if she eats the evidence.
What causes miscarriage in dogs?
There are numerous causes of miscarriage in dogs such as bacterial or viral infections, parasites, hormonal imbalance, genetic or placenta disorders. Let’s take a look at some common potential causes in a little more detail.
Brucella Canis is a bacteria that can cause a serious, very contagious disease in dogs. It can cause an infection of the uterus or abortion, and infertility in both male and female dogs. If a dog is infected with brucella, antibiotics can help but wont cure the disease, the dog will have it for the rest of it’s life.
Therefore, all dogs should be tested for this disease before breeding. Pregnant dogs infected with Brucellosis will usually abort the puppies at around 45-55 days, or will give birth to stillborn puppies, or weak puppies that will pass away when they are a few days old.
There are many other bacteria which may be associated with miscarriage in the dog including E. coli, Salmonella, Pasteurella, Pseudomonas, or Staphylococcus.
Some of these bacteria may be present in healthy female dogs and cause no problems.
In other cases, if the female dog has a poor immune system, a heavy worm burden or another underlying infection the bacteria can multiply and cause problems, including miscarriage.
Canine Herpes Virus (CHV)
Canine herpes virus can cause late stage abortion, as well as illness, seizures or sudden death in new born puppies. This viral disease is easily spread from direct contact with other infected dogs, and infection is for the rest of the dog’s life. Treatment is often unsuccessful, and most infected puppies die from herpes virus infection. A CHV vaccine is available in some countries.
Low Progesterone Level
Miscarriage can happen if there is a change in the normal hormonal balance, especially if there is a low level of progesterone. The hormone progesterone is essential to maintain a healthy dog pregnancy.
Low progesterone levels can be caused by ovary or placenta problems, infections and some medications. Veterinarians can test the level of progesterone in the dog’s blood, and supplement it if necessary to help protect the pregnancy.
Poor maternal health
If the mother dog has poor health, then this will definitely affect her ability to have a normal pregnancy and carry her pups for the full term. A hormone imbalance such as low thyroid hormones (Hypothyroidism), Cushings Disease, Addisons Disease or Diabetes, will make miscarriage more likely.
If the dog is eating a poor quality diet causing dietary deficiencies, such as a lack of magnesium or vitamin A, this may also lead to miscarriage. Uterine disease such as a cystic uterus, or endometritis (inflammation of the uterine lining) will make it difficult for the uterus to support the growth of the fetuses.
Fetal Developmental Abnormalities
If one or more of the unborn pups have a severe developmental abnormality, then the mother dog often has a miscarriage early in pregnancy.
These developmental problems may be due to genetic disease, birth defects or inbreeding.
Some medications should not be given to a pregnant dog as they might cause a miscarriage. Common examples include glucocorticoids, chloramphenicol, chemotherapy drugs or organophosphates.
Therefore, if your pregnant dog receives any medication from a veterinarian it is important to double check that it is suitable for pregnant dogs, and never self medicate your dog with over the counter or human medications.
Abdominal trauma can cause a dog to have a miscarriage, such as falling from a height, a hard collision with another dog or a road traffic accident. However, some heavy exercise can also increase the risk of trauma, such as field training or agility.
Therefore, they should ideally be postponed while the dog is pregnant. Talk to your vet about how much exercise is advised for your dog while she is pregnant, it will vary depending on her breed and fitness levels.
High stress levels can cause a mother dog to have a miscarriage. Stress actually causes chemical and hormonal changes in the body, and the longer the stress happens the worse the effects.
Therefore, it is important to keep a pregnant dog feeling secure, comfortable and happy. Try not to make nay big changes during this important time, such as having lots of visitors or strangers, doing loud renovation work or changing her normal routine.
How is a miscarriage diagnosed?
If miscarriage occurs early in pregnancy, then the fetus(es) are usually resorbed. This normally occurs before the first ultrasound scan and the bitch may show no signs at all, therefore it often goes undiagnosed.
If an owner has any concerns about a dog’s pregnancy then ultrasound is the most common way to assess the pregnancy, and determine if the unborn pups are doing ok.
Your veterinarian will be able to check the fetal size and heartbeats from around day 25-28.
Progesterone levels can be checked during pregnancy, and if they are found to be low this could also be sign of a failing pregnancy.
If your dog does suffer from an obvious miscarriage later in pregnancy, then it's a good idea to have both the mum and fetus tested to check for an underlying infectious cause.
This may include blood tests, a culture from the vaginal fluid and a culture and histopathology (microscopic exam) exam of the fetus. As difficult as this can feel at the time, if you and your vet know what you are dealing with you can help reduce the risk of your female dog having a painful miscarriage again in the future.
How is a miscarriage treated?
Unfortunately, once a miscarriage has started it is almost impossible to stop. However, sometimes only one fetus is aborted, and the veterinarian may have a chance to save some of the other unborn pups if the mum dog is taken for immediate emergency treatment.
If the abortion happens at the end of the pregnancy, the veterinarian may decide to do an emergency caesarean to try to save any unborn pups.
If a dog develops a fever or an abnormal discharge during pregnancy, this can often be an indication of an infection. The dog may need intravenous fluids and antibiotics, and regular ultrasound scans to monitor the fetuses.
Therefore, it is really important that if your dog is pregnant that she is monitored carefully for signs of miscarriage.
Sometimes these signs can be as simple as a change in behavior, a reduced appetite or a mild fever.
It is also a good idea to learn how to take your dog’s temperature at home, it is a valuable tool to help you decide if your dog is unwell.
How to deal with a miscarriage?
If a dog has had a miscarriage it can be a difficult and sad time for both owner and the mother dog. If the dog passes any dead pups, then these should be collected and wrapped in a towel, before bringing them to the veterinary clinic.
Gloves should be used to handle any birthing fluid or dead pups, there are some infectious agents which can infect humans too. The veterinarian will be able to check the female dog to ensure she is not at risk and check the health of any other unborn pups using ultrasound.
Finally, if the vet has consent, they will be able to take samples from the dead pup and mum dog if necessary, to find out what caused the dog to have a miscarriage.
The dog may require treatment such as antibiotics, but she will also require rest, careful monitoring and lots of attention (if she wants it).
The mother dog may also have physical pain and cramps, or vaginal bleeding or discharge after a miscarriage. Extra towels should be placed down to cover her bedding, which then can be easily removed and changed for fresh ones.
Wash used bedding and towels on a high temperature to kill any infectious agents. Keep the dog warm and comfortable, and her bed in a quiet place in the home.
Listen to the vet’s advice regarding the signs that should be expected, which will vary depending on the cause of the miscarriage and the stage of pregnancy.
Can miscarriage be prevented?
Unfortunately, there is no fail safe way to definitely prevent miscarriage in dogs. It probably happens much more than we know, as the early miscarriages are often reabsorbed and the dog shows no signs.
However, here are some useful tips that I tell all owners wishing to breed from their beloved dog, to help lower the female dog’s risk of miscarriage:
Miscarriage in dogs really can be heart breaking, especially if it occurs later in the pregnancy. Ultimately the goal is to determine what caused the miscarriage if possible, so that the underlying disease can be treated and future litters can be kept safe. Work closely with your veterinarian to keep your pregnant dog and her unborn pups as safe and healthy as possible.