What are the common causes of vaginal discharge in dogs and cats?

Common causes include infection, discharge related to the heat cycle, foreign-body irritation, or uterine disease such as pyometra. The exact cause requires a veterinary examination and diagnostics (e.g. cytology, culture, or blood tests) to confirm — please consult your vet.

How can I manage the discharge at home?

Start by recording the colour, odour, and volume of the discharge, keep the vulvar area clean, and prevent your pet from licking it. Take photos or collect a sample to bring to your vet so they can determine whether further investigation is needed.

What tests will the vet run to find the cause?

Common tests include urinalysis, vaginal cytology, bacterial culture and sensitivity testing, a blood panel, and — when indicated — tissue biopsy or PCR testing. The specific workup depends on the clinical presentation.

Can vaginal discharge spread to other animals or people?

Most cases are caused by a local infection or reproductive-tract issue and are not contagious. However, certain specific pathogens can be transmitted. Whether there is a contagion risk depends on the test results — discuss appropriate precautions with your vet.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Vaginal Discharge in Dogs & Cats: Causes, Symptoms & Home Care [2025]

Unspayed female dogs may develop vaginal discharge due to heat cycles, infection, or uterine disease — identifying the cause is essential for proper treatment

Take 1 minute to check the symptoms first

Last updated: 2026/01/06

Pethealthmap editorial team

Sources: WSAVA, ISFM, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate veterinary care (emergency)

•Heavy or persistent vaginal bleeding that does not stop
•Marked rapid breathing or panting
•Sudden loss of ability to stand, collapse, or unresponsiveness

Schedule a veterinary visit soon (within 24-72 hours)

•A clear change in the color or odor of the discharge
•Persistent decreased appetite or refusal to eat for more than 24 hours
•Repeated vomiting, marked depression, or lethargy

01What symptoms indicate something is wrong?

Vaginal discharge in dogs and cats is often accompanied by changes in appetite, energy, or urination. Noting the colour, odour, and volume of the discharge — along with any other systemic signs — helps gauge severity.

Change in discharge colour, volume, or odour (e.g. purulent or blood-tinged)
Noticeably reduced appetite or refusal to eat
Repeated vomiting or increased frequency of vomiting
Lethargy, significantly reduced activity level, or excessive sleepiness
Frequent urination, difficulty urinating, or persistent licking or scratching at the vulva

Seek emergency care immediately if you notice the following symptoms:

⚠️ Heavy or continuous vaginal bleeding requires immediate veterinary attention
⚠️ Persistent high fever or extreme lethargy should be assessed by a vet as soon as possible
⚠️ Rapid or laboured breathing, or sudden inability to stand

02How can you assess the situation at home? Key observation points and when to go to the emergency clinic

Careful home records and photos help your vet identify the likely cause and track progression more quickly — focus on timing and trends.

Note when symptoms started and whether they are getting worse
Track daily appetite and any changes in food intake or feeding response
Record the number of vomiting episodes, timing, and the colour or content of vomit
Observe daily differences in energy level, activity, and sleep patterns
Monitor urination and defecation frequency, straining, or any blood in urine
Photograph or video the discharge and vulvar area to share with your vet

03How will the vet diagnose the problem? Common diagnostic tests

At the clinic your vet will combine a physical examination with diagnostic tests to determine the underlying cause. Common investigations may include the following.

Urinalysis

rule out urinary tract infection or other urinary abnormalities

Vaginal cytology

microscopic examination for inflammation or abnormal cells

Tissue biopsy or histopathology

sample collection when indicated

Bacterial culture and sensitivity testing

identify the causative organism and appropriate antibiotics

PCR testing

detection of specific pathogens or viral nucleic acids

Complete blood count and biochemistry panel

assess systemic infection and organ function

04How is it treated and managed after diagnosis? Medications, dietary adjustments & care guide

After initial treatment your vet will arrange follow-up checks and home care instructions — monitor for improvement and keep records to help fine-tune the treatment plan.

Give all medications on schedule as directed by your vet and monitor for clinical changes
Attend all follow-up appointments to review test results and clinical progress
Schedule repeat culture or blood tests as needed to confirm treatment response
Adjust diet to provide easily digestible food or a prescription diet recommended by your vet
Keep the vulvar area clean and prevent your pet from excessively licking or irritating it
If symptoms do not improve, consider a specialist referral or further evaluation

05What should you prepare before the vet visit? Key information to help your vet diagnose quickly

Bring a symptom log and timeline, including appetite and vomiting records

List recent food, treats, and any changes in intake

Record the number, timing, and nature of vomiting or elimination episodes

Prepare a list of current medications, supplements, and vaccination history

Bring a discharge sample or photos/video for the vet to review directly

Consider booking a clinic with in-house laboratory equipment to speed up results

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.