Miscarriage in dogs (abortion)

  • Synonyms: Miscarriage, stillbirth, abortion
  • Occurrence: common
  • Location of disease: Abdomen/pelvis
Author: Dr. med. vet. Gisa Löwe | Last modified: 07.07.2026
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Definition

An abortion (miscarriage) in a female dog is the loss of puppies before they reach viability. The pregnancy ends prematurely. A premature end to pregnancy can occur at any time during gestation. If the pregnancy ends in the early stage, fetal resorption usually occurs. If the pregnancy ends after day 30 of gestation, it is referred to as an abortion. The puppies are stillborn or, in late pregnancy, may be born partially alive but die shortly after birth. Overall, abortion in female dogs is relatively rare.

The most important facts at a glance

A miscarriage in a female dog can have many causes, including infections (e.g. Brucella canis), hormonal imbalances (e.g. progesterone deficiency), as well as anatomical and hereditary factors. Recent research focuses on improved diagnostics using PCR, close hormonal monitoring, and prevention (such as hygiene measures and health checks of both parent animals before mating). If there are signs of an impending abortion, rapid veterinary clarification is crucial. An online Symptom Checker like petsvetcheck.de can provide initial guidance but does not replace clinical diagnosis. With timely and targeted therapy, the female dog can often remain successfully reproductive.

Causes

  • Bacterial or viral infections
  • Hormonal imbalances
  • Genetic defects of the fetuses
  • Toxic exposure
  • Nutritional deficiencies
  1. Infectious causes
    • Bacteria:
      • Brucella canis (bacterial brucellosis) is one of the most well-known causes of abortions. It is also a zoonosis (transmissible to humans).
      • Escherichia coli, Streptococcus species, Staphylococcus species, or other pathogens may also be involved.
    • Viral pathogens:
      • Canine herpesvirus (CHV-1): Often responsible for neonatal deaths in puppies, but can also lead to late-term abortions.
      • Other viruses such as parvovirus (although less common than in unvaccinated female dogs) may also play a role.
    • Protozoa & parasites:
      • More rarely, e.g. Neospora caninum or toxoplasmosis (more common in cats, but also possible in dogs in rare cases).
  1. Hormonal and endocrine disorders
    • Progesterone deficiency: Progesterone is essential for maintaining pregnancy.
    • Thyroid dysfunction (hypothyroidism) is discussed as a potential contributing cause.
  1. Genetic and anatomical causes
    • Congenital malformations of the uterus, e.g., deformities inside the uterus (septa, diverticulum), can increase the risk of abortion.
    • Hereditary anomalies in the embryos or chromosomal defects in the parent animals.
  1. Environmental and management factors
    • Stress, traumatic events (accident, fall), toxic substances (pesticides, medications).
    • Inadequate nutrition and deficiencies (e.g., calcium, vitamins) can generally impair the stability of the pregnancy.
  1. Immune system and autoimmune processes

Symptoms

Rare symptoms:

The clinical signs of an abortion vary depending on the stage of pregnancy and the cause:

In early abortions, symptoms may be minimal or entirely absent, as the embryos are often resorbed. The female dog may only show a brief vaginal discharge or behavioral changes. In late abortions, the fetuses are expelled, accompanied by contractions and abdominal pressing. The vaginal discharge can be serous, bloody, or purulent, depending on the cause.

Systemic symptoms such as fever, lethargy, inappetence, and dehydration can occur, especially in infectious causes. In the case of an incomplete abortion, if parts of the placenta or fetuses remain, metritis (inflammation of the uterus) can develop, which can lead to septic shock.

Behavioral changes such as nesting behavior, Restlessness, or excessive Licking of the genital area may be observed. After an abortion, the female dog may develop pseudolactation, in which the mammary glands swell and produce milk.

Diagnosis

  • Clinical examination and medical history
  • Ultrasound examination to check the status of the pregnancy
  • Blood tests to identify infections or hormonal disorders
    • PCR tests (polymerase chain reaction) allow rapid and precise identification of infectious agents such as Brucella canis or canine herpesvirus.
    • Serological tests (e.g. antibody detection) are still the standard for confirming infections.
  • Examination of the aborted material, if available, to determine the cause
  • High-resolution ultrasound examinations enable early detection of developmental disorders in the fetus and can provide indications of impending abortions (e.g., missing heartbeat, reduced amniotic fluid volume).

Therapy

  • Treatment of underlying infectious causes with antibiotics or antiviral medications
  • Hormonal therapy for identified imbalances
  • Supportive care for the female dog, including fluid therapy and nutritional support
  • Detoxification measures in cases of toxic exposure
  1. Hormone management
  • Current studies are evaluating approaches to supplement progesterone externally in cases of progesterone deficiency. However, the risk of side effects (e.g., cholestasis, uterine inflammation) must be weighed.
  • Close monitoring of progesterone levels can detect impending abortions early.
  1. Breeding hygiene and breeding management
  • Strict breeding selection and testing for genetic diseases in the respective breeds.
  • The trend towards closer cooperation between laboratories, veterinarians, and breeders leads to earlier detection of risk factors.
  1. Multimodal treatment
  • If an abortion is imminent, veterinarians use medications (antibiotics, progesterone preparations, immunomodulators) depending on the cause.
  • There are new studies on supporting pregnancy through a combination of micronutrients (e.g. antioxidants, omega-3 fatty acids) – however, the effectiveness is sometimes still the subject of research.
  1. Prevention strategies
  • Vaccination against canine herpesvirus is discussed in some breeding contexts, although no nationwide standard vaccination has yet been established in Germany.
  • Strict hygiene and control in breeding dogs: regular examinations for Brucella canis.
  • Careful breeding planning with prior testing of progesterone levels, as well as health checks of both parent animals, minimizes the risk of hormone-related abortions and preventable infections.

Prognosis and follow-up care

  • The prognosis depends on the cause of the abortion and the general health of the female dog. It is generally good. The female dog often recovers without further complications. Even with a pathological background, many female dogs can have a normal pregnancy in the future with appropriate treatment and care.
  • In cases of repeated abortions (especially if they occur in late pregnancy), underlying diseases or genetic factors should be investigated thoroughly.
  • After an abortion, it is important to check the uterus and the general condition to prevent secondary damage (e.g., endometritis).

Prevention

The prevention of abortions in female dogs begins even before mating. A thorough veterinary examination, checking vaccination status, and deworming are important to avoid infections. Breeding animals should be tested for hereditary diseases and hormonal disorders. During pregnancy, stress should be minimized and the female dog protected from injuries. Contact with infected animals, especially in the case of brucellosis or canine herpesvirus, must be strictly avoided. High-quality, pregnancy-specific nutrition and a clean, quiet environment promote a stable pregnancy. Regular ultrasound checks help to identify problems early and take countermeasures.

Outlook on current research

Research in the field of reproductive disorders in pets is increasingly focusing on molecular and genetic factors that can lead to abortions. New diagnostic methods such as next-generation sequencing allow the identification of previously unknown pathogens and genetic defects. The development of specific immunological tests could enable early detection of risk factors for abortions in the future.

Frequently asked questions (FAQs)

1. How can I tell if my female dog has had an abortion?
Common signs include Bleeding or discharge from the vagina, sudden cessation of pregnancy signs (e.g., reduced mammary development), apathy, Fever, or loss of appetite. If in doubt, a veterinary examination (e.g., ultrasound) should always be performed to determine whether an abortion is impending or has already occurred.
2. How is an abortion in a female dog diagnosed by a veterinarian?
Usually through a combination of ultrasound (checking the fetuses’ viability), blood tests (hormone status, infection markers), and vaginal swabs to identify the pathogen. If needed, an X-ray examination can also be performed in late pregnancy to assess the puppies.
3. What are the most common causes of miscarriage in dogs?
Infectious agents (e.g., Brucella canis, canine herpesvirus), hormonal disorders (progesterone deficiency), stress, poor mating hygiene, genetic defects, or anatomical abnormalities of the uterus.
4. Can I prevent a miscarriage in my female dog?
Yes. Regular veterinary checks before and during pregnancy (including progesterone measurement, Brucella canis tests, etc.), good hygiene during mating, balanced feeding, avoidance of stress, and vaccinations (according to veterinary recommendation) can reduce the risk of an abortion.
5. Is a female dog permanently infertile after a miscarriage?
Not necessarily. Many female dogs are successfully mated again at the next heat after a miscarriage and carry the puppies to term. However, if abortions recur, comprehensive diagnostics (e.g., hormone check, examination for uterine anomalies) should be performed.
6. What can I do if I notice unusual discharge or Restlessness in my pregnant female dog?
Arrange an immediate veterinary examination. A Symptom Checker (such as petsvetcheck.de) can provide initial clues, but it does not replace on-site clinical diagnostics. Rapid assessment is crucial to take timely action against an impending abortion if necessary.
7. Can infectious agents that cause an abortion be transmitted to humans?
With Brucella canis, there is a zoonosis risk (transmission to humans is possible, though rare). Other pathogens (e.g., bacterial infections) are less commonly transmissible; nevertheless, consistent hygiene (wearing gloves, disinfecting surfaces) is always advisable.
8. What role does the progesterone level play in maintaining pregnancy?
Progesterone is the key hormone that stabilizes the uterine lining and maintains pregnancy. A level that is too low (progesterone deficiency) can trigger abortions. That is why hormone status is often monitored and, if necessary, supported artificially.
9. Is treatment always possible when an abortion is imminent?
That depends on the cause and the timing. In infections, appropriate drug treatment (antibiotics) can help. For hormonal disorders, there are approaches to supplement progesterone. However, not every impending abortion can be prevented—the later the process is recognized, the less favorable the prognosis.
10. What should you do after an abortion in a female dog?
Thorough veterinary follow-up care is important. This includes ultrasound checks to verify that all pregnancy tissue has been expelled. It should also be clarified whether an underlying condition (infection, uterine problem, etc.) is present. In some cases, a late consequence can be a uterine infection (pyometra), which is why close monitoring is advisable.

Literature

  • Mantziaras, G., & Zakosek Pipan, M. (2025). “My bitch is empty!” An overview of the reasons for pregnancy loss in dogs. Veterinary Sciences, 12(2), 127. https://doi.org/10.3390/vetsci12020127
  • Fontbonne, A. (2023). Causes of pregnancy arrest in the canine species. Reproduction in Domestic Animals, 58, 72–83. https://doi.org/10.1111/rda.14407
  • Lamm, C. G., & Njaa, B. L. (2012). Clinical approach to abortion, stillbirth, and neonatal death in dogs and cats. Veterinary Clinics of North America: Small Animal Practice, 42(3), 501–513. https://doi.org/10.1016/j.cvsm.2012.01.015
  • Schlafer, D. H. (2008). Canine and feline abortion diagnostics. Theriogenology, 70(3), 327–331. https://doi.org/10.1016/j.theriogenology.2008.05.036
  • Verstegen, J., Dhaliwal, G., & Verstegen-Onclin, K. (2008). Canine and feline pregnancy loss due to viral and non-infectious causes: A review. Theriogenology, 70(3), 304–319. https://doi.org/10.1016/j.theriogenology.2008.05.035
  • Santos, R. L., Souza, T. D., Mol, J. P. S., Eckstein, C., & Paíxão, T. A. (2021). Canine brucellosis: An update. Frontiers in Veterinary Science, 8, Article 594291. https://doi.org/10.3389/fvets.2021.594291
  • Rota, A., Dogliero, A., Biosa, T., Messina, M., Pregel, P., & Masoero, L. (2020). Seroprevalence of Canine Herpesvirus-1 in breeding dogs with or without vaccination in Northwest Italy. Animals, 10(7), 1116. https://doi.org/10.3390/ani10071116
  • Stefanetti, V., Compagnone, A., Sordini, C., Passamonti, F., Rampacci, E., Moscati, L., Marenzoni, M. L., & Coletti, M. (2018). Retrospective biomolecular investigation of Coxiella burnetii and Leptospira spp. DNA in cases of abortion, stillbirth and neonatal mortality in dogs and cats. Topics in Companion Animal Medicine, 33(4), 122–125. https://doi.org/10.1053/j.tcam.2018.08.005