Vaginal Discharge in Dogs

Vaginal discharge in dogs can range from normal to life-threatening. In an unspayed dog, a small amount of bloody discharge is expected during heat. Outside of heat, though, discharge from the vulva is a symptom, not a diagnosis. It may come from the vagina, uterus, urinary tract, or skin folds around the vulva. The color, odor, amount, and timing all matter. Clear mucus may be less concerning than thick yellow, green, pus-like, or foul-smelling discharge.

One of the most important causes to rule out is pyometra, a serious uterine infection that affects unspayed females and can become fatal without prompt treatment. Vaginitis is another common cause and may occur in puppies, adult dogs, or dogs with underlying urinary or conformational problems. Some dogs also develop discharge from urinary tract infections, trauma after breeding, foreign material in the vagina, skin fold inflammation, or less commonly tumors and reproductive tract abnormalities.

Because several very different problems can look similar at home, it is safest to have your vet evaluate any discharge that is new, persistent, smelly, or associated with licking, scooting, straining to urinate, fever, vomiting, poor appetite, or low energy. A dog who seems sick overall should be seen the same day. Early evaluation often gives pet parents more treatment options and may lower the total cost range by catching a problem before it becomes an emergency.

Normal heat-related discharge is one possible explanation in an intact female dog. During estrus, discharge is often bloody or pink and happens along with vulvar swelling and behavior changes. That said, not every bloody discharge is heat. If the timing is unusual, the odor is bad, or your dog seems unwell, your vet should check for disease rather than assuming it is reproductive cycling.

Vaginitis is a common cause of vulvar discharge and may lead to mucus, pus, or occasional blood-tinged spotting. Dogs may lick the area, urinate more often, scoot, or attract male dogs. In puppies, vaginitis often improves after the first heat cycle. In adults, it is more likely to have an underlying trigger such as urinary incontinence, recessed vulva, skin fold irritation, urinary tract infection, foreign material, an anatomic abnormality, or another reproductive problem.

Pyometra is the most urgent cause to consider in an unspayed female, especially a middle-aged or older dog that was in heat within the last several weeks. Open pyometra may cause cream-colored, bloody, or foul discharge. Closed pyometra may cause little to no visible discharge but can make a dog very sick. Other possible causes include urinary tract infection, trauma from mating, pregnancy-related complications, brucellosis in breeding dogs, vaginal or uterine tumors, and ovarian remnant syndrome in a previously spayed dog.

See your vet immediately if your dog has vaginal discharge plus lethargy, vomiting, weakness, collapse, fever, a swollen or painful belly, pale gums, increased thirst, or increased urination. Those signs raise concern for pyometra or another serious infection. The same is true for thick yellow, green, gray, or pus-like discharge, a strong foul odor, or heavy bleeding. If your dog is pregnant, recently gave birth, or may have been bred, abnormal discharge also needs urgent attention.

Schedule a prompt visit within 24 to 48 hours for milder but persistent discharge, repeated licking of the vulva, scooting, urinary accidents, straining to urinate, or discharge that appears after urination. Even if your dog seems comfortable, discharge outside a normal heat cycle is not something to monitor for long at home. A spayed dog with vaginal discharge should also be examined, because discharge in a spayed female is never considered normal.

If your dog is in heat and the discharge seems typical for her, you may not need emergency care. Still, call your vet if the bleeding is much heavier than expected, lasts unusually long, smells bad, or is paired with illness. When pet parents are unsure whether discharge is normal heat or a medical problem, a quick call and exam can help sort that out safely.

Your vet will start with a history and physical exam. Helpful details include whether your dog is spayed, when her last heat cycle occurred, whether she may be pregnant or recently bred, what the discharge looks and smells like, and whether there are signs like licking, urinary accidents, vomiting, or low energy. A careful exam of the vulva and surrounding skin can help identify dermatitis, conformational issues, trauma, or obvious discharge.

Common first-line tests include urinalysis, urine culture when infection is suspected, bloodwork, and vaginal cytology. Cytology can help your vet look at the types of cells and inflammatory changes present. In some dogs, your vet may recommend vaginal culture, especially when discharge is recurrent or not responding as expected. These tests help separate urinary causes from vaginal or uterine disease.

Imaging is often important. X-rays or ultrasound may be used to look for an enlarged, fluid-filled uterus, retained material, masses, pregnancy-related problems, or other abdominal changes. Some dogs also need vaginoscopy, which uses a small camera to inspect the vaginal canal for foreign material, strictures, masses, or anatomic abnormalities. Diagnosis matters because treatment for vaginitis, UTI, and pyometra can be very different.

Home care depends on the cause, so it should follow your vet’s plan. Until the appointment, keep the vulvar area clean and dry. You can gently wipe away discharge from the surrounding skin with a soft cloth or dog-safe wipe if your dog tolerates it. Avoid human creams, peroxide, or scented products unless your vet specifically recommends them. An e-collar may help if your dog is licking constantly and making the area more irritated.

Watch for changes in color, odor, and amount of discharge. Also monitor appetite, energy, thirst, urination, bowel movements, and belly comfort. If your dog is intact, note the date of her last heat cycle because that timing can be very important. If she is pregnant, recently delivered puppies, or was recently bred, tell your vet right away.

Do not assume discharge is minor because your dog still seems bright. Pyometra can progress quickly, and some dogs with open pyometra may still be walking around and eating early on. If your dog develops vomiting, weakness, collapse, fever, abdominal swelling, or worsening discharge, seek same-day care. Follow-up matters too. Rechecks help your vet confirm that infection, inflammation, or urinary problems have truly resolved.