TL;DR: Dark or bloody vaginal discharge in a dog not in heat is a medical emergency often caused by pyometra, a life-threatening uterine infection. Seek immediate veterinary care to prevent fatal complications such as sepsis or uterine rupture.
What does it mean if my dog has dark or bloody vaginal discharge?
Finding dark or bloody discharge from your dog's vulva when she is not in her heat cycle is a significant clinical sign. This discharge, which may appear reddish-brown, chocolatey, or like "tomato soup," often indicates:
- An underlying infection or inflammation
- Trauma within the reproductive tract
- Urinary system issues
Is dark bloody discharge in dogs considered a medical emergency?
Yes, the urgency level for this symptom is high. Potential causes requiring urgent diagnosis include:
- Pyometra: A life-threatening uterine infection and surgical emergency that can lead to fatal sepsis if the uterus ruptures.
- Severe urinary tract infections
- Vaginitis
- Reproductive tumors
How can taking a photo of the discharge help with my dog's veterinary triage?
If your dog is stable, taking a clear, well-lit photo of the discharge on a white paper towel can be incredibly helpful for the veterinary triage team because:
- It allows medical staff to see the exact color, consistency, and volume of the fluid.
- It helps the team differentiate between various conditions.
- It allows the clinic to prioritize your dog's care the moment you arrive.
Clinical Context (Merck Veterinary Manual)
Hemorrhagic uterine discharge from the vulva in a dog that is not in heat can be indicative of several conditions, including subinvolution of placental sites (SIPS), metritis, vaginitis, or cystitis. SIPS is most common in young bitches after whelping a first litter, characterized by hemorrhagic uterine discharge for several weeks postpartum, with the bitch otherwise appearing normal. Pyometra, especially in a diestrual bitch, should also be suspected, and can be confirmed via history, physical examination, abdominal radiographs, and ultrasonography. Vaginal cytology can aid in determining the nature of the vulvar discharge, while a complete blood count, biochemical profile, and urinalysis can help exclude other causes and evaluate renal function, acid-base status, and presence of septicemia.
Chapter: Reproduction
Source: The Merck Veterinary Manual, 11th Edition (Page 1399)