Dog Swollen Vulva Weeks After Heat: Causes and When to See a Vet

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Dog · Swollen Vulva Weeks After Heat Cycle
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TL;DR: Swelling of the vulva weeks after a heat cycle may indicate a life-threatening uterine infection called pyometra; contact a veterinarian within 24-48 hours, or seek emergency care immediately if your dog is lethargic or vomiting.

What does it mean if my dog has a swollen vulva after her heat cycle?

While swelling of the vulva is a normal part of the canine estrus cycle, it typically recedes once the 'heat' phase concludes. If you notice persistent or new swelling several weeks after the bleeding has stopped, it may indicate an underlying medical issue. Common causes include localized inflammation, a urinary tract infection, or vaginitis. However, the most significant concern during this specific timeframe is Pyometra—a serious and potentially life-threatening bacterial infection of the uterus that typically occurs 2 to 8 weeks after a heat cycle due to hormonal changes.

Is a swollen vulva after a dog's heat cycle considered a veterinary emergency?

  • Schedule a veterinary appointment within the next 24 to 48 hours for a physical exam and possibly blood work or an ultrasound.
  • Seek immediate emergency care if your dog shows signs of lethargy, decreased appetite, vomiting, or excessive thirst, as these are symptoms of a life-threatening uterine infection.

How can providing a photo of the area help with veterinary triage?

  • Clear, well-lit photos allow veterinary professionals to assess the presence, color, and consistency of any discharge.
  • Visual assessments help determine the degree of tissue inflammation and identify visible masses or abnormalities.
  • This information helps your vet decide if your dog needs immediate emergency surgery or can wait for a scheduled appointment, potentially saving her life.

Clinical Context (Merck Veterinary Manual)

Vaginal hyperplasia, a proliferation of the vaginal mucosa, can occur during proestrus and estrus due to estrogenic stimulation, resulting in a mass protruding from the vulva and a slight vaginal discharge. While the hyperplastic tissue is near the urethral orifice, dysuria is uncommon, but it can interfere with copulation. Diagnosis is based on history (stage of estrous cycle) and vaginal examination. Metritis, characterized by a large, flaccid uterus, abnormal vaginal discharge, and potential systemic illness, should also be considered; radiographs and a hemogram are recommended for diagnosis. If systemic illness is present, immediate veterinary attention is warranted.

Chapter: Reproduction

Source: The Merck Veterinary Manual, 11th Edition (Page 1399)

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Compiled by the CheckPet Editorial Team, aligned with the Merck Veterinary Manual. Last updated June 30, 2026.

This article is for general informational purposes only and is not a substitute for professional veterinary advice, diagnosis, or treatment. If you think your pet may be unwell, contact a licensed veterinarian.

Frequently Asked Questions

Could my dog still be in heat after several weeks?
While heat cycles vary, the swelling should generally decrease once the fertile window passes. Persistent swelling weeks later is unusual and warrants a checkup.
What does Pyometra discharge look like?
If it is an 'open' pyometra, you may see a foul-smelling discharge that is yellow, green, or bloody. A 'closed' pyometra has no discharge but is more dangerous as the infection is trapped inside.
Can a spayed dog have a swollen vulva?
Yes, though it is less common. It could be caused by 'ovarian remnant syndrome,' where a small piece of ovarian tissue was left behind, or a simple skin fold infection.

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