TL;DR: Yellow or foul-smelling vaginal discharge in a cat is a life-threatening medical emergency, often indicating a uterine infection (pyometra) that requires immediate veterinary intervention and surgery.
What does yellow or foul-smelling vaginal discharge mean for my cat?
Thick, opaque, yellow, or foul-smelling discharge from a cat's vulva is most commonly a sign of a serious infection. The most frequent cause is pyometra, a life-threatening infection of the uterus where pus accumulates inside the organ. It may also indicate severe vaginitis or a uterine stump infection if the cat has been spayed. Regardless of the exact cause, yellow discharge indicates the presence of white blood cells and bacteria, requiring professional intervention.
Is yellow vaginal discharge a medical emergency for my cat?
- Contact an emergency veterinarian immediately, as this is an absolute medical emergency.
- Pyometra can lead to sepsis, organ failure, or a ruptured uterus within hours.
- Do not wait for an appointment or observe her overnight; immediate stabilization and likely surgery are necessary to save her life.
How can taking a photo of the discharge help my cat get treated faster?
- Showing a clear photo allows the triage team to immediately assess the color, consistency, and volume of the fluid.
- Visual evidence helps the vet differentiate between normal post-heat spotting and an emergency infection.
- Sharing a photo helps ensure your cat receives the fastest possible care upon arrival at the clinic.
Clinical Context (Merck Veterinary Manual)
A yellow vulvar discharge in a cat can indicate ulcerative vulvitis or pyometra, a potentially life-threatening condition. Ulcerative vulvitis presents with vulvar inflammation, swelling, redness, yellow exudate, ulceration, and scab formation. Pyometra, particularly when the cervix is open, can manifest with a purulent, often bloody, vulvar discharge along with lethargy, anorexia, polyuria, polydipsia, and vomiting. Given the potential severity, prompt veterinary examination is warranted to determine the underlying cause through physical examination, vaginal cytology, complete blood count, biochemical profile, urinalysis, abdominal radiographs, and ultrasonography, and to initiate appropriate treatment, which may include ovariohysterectomy or medical management with antibiotics and supportive care.
Chapter: Dermatology, Infectious Diseases, Reproduction
Source: The Merck Veterinary Manual, 11th Edition (Page 1372)