A miscarriage in dogs is the same as in humans, but much rarer. A miscarriage can occur at any time from conception until full term when the fetuses inside the dog’s womb are become no longer viable.

There are numerous reasons which can cause a miscarriage ie: bacterial infections, parasites, hormonal or even genetic conditions.

In the early stages of a dogs pregnancy, the dam can absorb the placental and fetal tissue from the uterus back into the body leaving no sign that the puppies every existed, this is normally referred to as re absorption. This can make it extremely difficult for dog owners to detect and may leave you wondering whether the puppies were ever there in the first place unless it has been confirmed by ultrasound. If the mother does not spontaneously absorb her puppies, she may expel them through the birth canal, she may also experience a lot of bleeding. Even then, she may lick and eat the evidence of the miscarriage, leaving you none the wiser.

There is no clear data, but most believe that a miscarriage is generally caused by a hormone imbalance and possibly low progesterone levels. Miscarriages may also be triggered by infection and bacteria, the most common being 'Brucella canis, or a parasite ie:  'Neospora caninum' which is found in contaminated food and water and in some fungi.

The typical sign of a miscarriage is a discharge, usually bloody, and green or black in colour, it can also be quite smelly and thick with puss. As a bitch will generally lick herself clean, it may not be apparent initially, but if you notice her cleaning herself more than normal you should check her vulva for any signs of blood loss and contact your vet.

If your dog looks visibly pregnant one day and the next she does not, this could be an indication she has miscarried. Your bitch may have spontaneously absorbed her litter or expelled it via the birth canal, this will be more noticeable in dogs who were closer to term and who expelled the fetusthrough the birth canal.

Dogs who reabsorb their litter usually do so early on in pregnancy when they look less pregnant anyway, making it harder to detect abdominal changes. Most female dogs do not begin to look pregnant until around 35 days gestation and if your dog miscarries before this time it is unlikely you will notice any physical abdominal changes.

If your dog spontaneously absorbs her litter, they will disappear without a trace. But, if she expels them via the birth canal, you may find the foetus yourself. Sometimes the female instinctively eats the foetus or she may eat them in part, making them difficult to identify. If you find anything alarming and you are unsure what it is, take photos or collect the evidence in a suitable container and take it to your vet. In some rare occasions, your female dog may need a cesarean section to extract the dead puppies remaining in her uterus.


Dams who have been infected with Brucella canis will usually miscarry much later into the pregnancy at around 45 to 55 days. Before your dog gets pregnant, she should be tested for Brucellosis and should not be bred until she is given the all clear. If your dog miscarries due to Brucella Canis she is also at risk of infecting other dogs and causing them to miscarry. The bacteria will be contained in any blood, discharge or foetuses that she expels, so these should be quickly and carefully disposed of to prevent the spread of bacteria. Brucella Canis also has the potential to render your dog infertile or lead to stillbirth.

You should also ensure that the male dog who you wish to breed your female dog with has been cleared of Brucellosis as it can be sexually transmitted and it is not wise to breed from either the dog or the bitch while they are infected.


A mycotic abortion stems from mycosis, which is caused by fungus. The fungus causes the uterus to excessively bleed, which will eventually result in abortion. This excessive bleeding is not only dangerous for the litter, but also for the mother. There are usually no warning signs prior to a mycotic abortion making them very hard to predict. It is unlikely you will know anything about it until after your dog has aborted the litter.

At present, mycotic abortions are somewhat mysterious in nature and it is difficult to know how to prevent them. The fungus is present in the natural environment and can be introduced into the body in an endless number of ways like stagnent water where the fungus is present.


Neospora caninum is a parasite responsible for spontaneous abortion in dogs as well as many other animal species. A dog will usually become infected if they ingest contaminated food, water, animal flesh or feces. It gets into the female dog’s bloodstream and passes across the placenta into the foetus.

Although transmission of Neospora caninum from mother to puppy is rare, it is still crucial to take precautions and be sure you know what your dog is eating and drinking and where she is roaming. Don’t let her near areas where parasitic or bacterial outbreaks have been reported and if she does abort her pregnancy, take her to a vet as soon as possible for testing and treatment.


If progesterone levels in your pregnant dog drop low enough she may be at risk of losing her puppies. A blood test will usually determine whether your dog’s pregnancy loss was due to plummeting progesterone levels. Often, if progesterone levels are monitored throughout pregnancy and treated with medication when low, losses can be avoided.

A dog with very low progesterone levels will usually be unable to carry the litter for the full 63-67 days. The hormone imbalance can cause numerous issues from uterine bleeding to contractions, resulting in premature labor. If your dog has a history of one or more spontaneous early-term miscarriages, you may want to discuss starting her off on progesterone supplements as soon as she conceives because once she starts to abort her puppies there is no stopping it.


There are several inherited disorders and diseases that may cause a spontaneous abortion in your female dog. Endocrine disorders such as Cushing’s disease, hypothyroidism and hypoadrenocorticism are commonly associated with pregnancy losses. If your dog has any of these disorders, she may be prone to recurrent miscarriages or complications.

Many genetic defects can be managed or treated to ensure that they do not interfere with the pregnancy, but there is no guarantee that the resulting litter will not inherit these disorders. If you are thinking about breeding your bitch, its best to identify any existing genetic defects prior to impregnation.

Once your female dog begins to spontaneously abort or absorb her litter, there is nothing you can do to stop it. If in the latter stages of gestation, an ultrasound will confirm if the puppies are alive and viable. Routine ultrasound scans throughout the pregnancy will help to keep a check of litter viability and blood tests can confirm a hormone inbalance if the bitch has had problems with a previous litter. The earlier that blood tests identify abnormalities, the earlier medication or supplements can be given to the mother to prevent it again.