Understanding Spontaneous Abortion & Pregnancy Loss in Dogs – Vet Guide 2025🩺

By Dr. Duncan Houston BVSc

Hello, I’m Dr Duncan Houston, BVSc, founder of Ask A Vet. In this comprehensive 2025 veterinary update, we’ll explore spontaneous abortion and pregnancy loss in dogs, covering causes, signs, diagnostic strategies, treatment options, prevention measures, and at-home care. Whether you're a breeder or devoted pet parent, this article offers clarity, empathy, and professional insight. 🐾

📘 What Counts as Pregnancy Loss?

“Pregnancy loss” or “spontaneous abortion” describes the death of a fetus or litter before term. In early gestation (<45 days), fetal death often results in absorption—sometimes unnoticed. Later losses may present as abortions, stillbirths, or fetal mummification .

🧬 Causes: Infectious vs. Non‑Infectious

🔬 Infectious Causes

• Brucella canis: Causes late-term abortion, vaginal discharge, and can lead to chronic infection.
• Bacterial pathogens: Escherichia coli, Streptococcus, Salmonella, Campylobacter, Mycoplasma/Ureaplasma.
• Viral agents: Canine herpesvirus, distemper virus, parvovirus.
• Protozoa: Neospora caninum, Toxoplasma gondii (rare).

⚠️ Non-Infectious Causes

• Hormonal imbalances: progesterone deficiency (hypoluteoidism), hypothyroidism, Cushing’s, diabetes.
• Uterine health issues: cystic endometrial hyperplasia, pyometra, uterine trauma or tumors.
• Fetal defects: lethal congenital abnormalities.
• Medications or toxins: steroid drugs, chemotherapeutics, organophosphates, heavy metals, pesticides.
• Physical trauma or stress: falls, intense exercise, environmental stressors.
• Genetic or chromosomal abnormalities, especially in purebred lines.

🚩 Symptoms & Clinical Signs

Symptoms vary with stage of loss:

• Early gestation: Often no signs, fetuses may be resorbed unnoticed.
• Mid to late pregnancy loss: Vaginal spotting, brown/green/black/pus-like discharge, fetal or tissue expulsion.
• Systemic signs: Fever, lethargy, decreased appetite, abdominal pain.
• Infections: Pyometra may mimic abortion with discharge and fever, but is life-threatening.

🔎 Diagnosis: A Step‑by‑Step Approach

1. History & Exam: Breed, age, gestational stage, exposure to pathogens or toxins.
2. Ultrasound/X‑ray: Assess fetal viability, detect retained tissue.
3. Bloodwork: CBC, biochemistry, progesterone levels, thyroid panel.
4. Microbiology & Cytology: Vaginal/uterine swabs, cultures from fetal membranes.
5. Virus/Parasite Testing: PCR or serology for herpesvirus, Neospora, Toxoplasma.
6. Histopathology: Exam of aborted fetuses/placenta to identify infection or congenital defects.
7. Progesterone monitoring: Particularly with suspected hypothyroidism—aim to maintain ≥2 ng/mL .

💉 Treatment Strategies

1. Infectious Loss

• Hospitalization for severe cases (pyometra, toxemia).
• Empiric broad-spectrum antibiotics, adjusted after culture.
• Removal of retained tissue surgically if needed.

2. Hormonal Support

For hypothyroidism or low progesterone, supplement using synthetic progesterone under careful monitoring. Successful salvage protocols have been documented.

3. Medical Induction

If pregnancy is unwanted or retention occurs, prostaglandin F2α protocols (e.g., cloprostenol) safely evacuate the uterus, often combined with misoprostol or dexamethasone.

4. Addressing Underlying Conditions

Treat underlying thyroid or endocrine issues, remove toxins, stabilize maternal health.

5. Surgical Intervention

Spaying with ovariohysterectomy may be recommended in non-breeding bitches with uterine disease or repeated losses.

🏠 At‑Home Care & Monitoring

1. Provide rest and minimize stress.
2. Monitor discharge and maternal behavior.
3. Maintain hydration; clean bedding and environment.
4. Follow medication schedules closely, especially antibiotics or hormone treatments.
5. Schedule follow-ups with ultrasound or hormone testing.

✅ Prevention & Breeder Recommendations

• Pre‑breeding health screening: test for Brucella, optimize endocrine function.
• Maintain up-to-date vaccinations to reduce viral risks.
• Avoid high-stress activities or toxins during pregnancy.
• Use progesterone monitoring in high-risk bitches.
• Manage kennel hygiene, vector control, and breeding biosecurity.

📅 Prognosis & Future Pregnancies

• Single loss often has good prognosis if the underlying issue is identified and treated.
• Recurrent or infectious losses require thorough investigation and management.
• Managed well, many bitches go on to have healthy future litters.

🔑 Role of Ask A Vet

Need tailored advice or monitoring support? Chat 24/7 with Ask A Vet to guidance on diagnostics and treatment plans, safe stress relief products.nurturing distractions and emotional enrichment during recovery.

🧾 Final Takeaways

Spontaneous abortion in dogs has many possible causes—infectious, hormonal, genetic, or traumatic. Early detection, accurate diagnosis, and prompt veterinary care give the best outcomes. Prevention through health screening and careful management is essential for breeding success and maternal wellbeing. With the right support, bitches can recover and carry healthy litters in future.

If you need real‑time guidance or reassurance, reach out through Ask A Vet or download our app for 24/7 vet support.