I often received questions regarding vulvar discharge in bitches and queens (after all, I am a diplomate of the European College of Animal Reproduction, that is definitely a topic I am familiar with!). Very often in fact people wonder if it is normal or not. The answer to that is quite simple: vulvar discharge of any type in diestrus should be considered abnormal.
Diestrus = progesterone impregnation
At this point, you might wonder what diestrus is. To make it short, it is the specific stage of the estrus cycle that goes from ovulation to parturition in mammalian species. In bitches it usually consists in the 63 days that follow ovulation, while it is 65 days in queens (we touch on it during our previous webinars on canine and feline reproduction , just click on the previous hyperlinks for a more detailed explanation). During this period, the ovaries essentially produce progesterone. This hormone is essential to maintain gestation (basic rule: no progesterone = no pregnancy). However, since it stimulates the growth of uterine glands and it blocks uterine contractions, it is also a predisposing factor for uterine diseases’ development.
Fig 1: Progesterone is produced during the diestrus in bitches and queens
Vulvar discharge in diestrus: what to do then?
If you observe vulvar discharge in your breeding animal in the two month period following their season or the breedings, you should always worry, whatever their color (brownish, bloody, green, black, white, etc.). In the bitch, sometimes you can observe a blackish vulvar discharge a few days after the optimal fertility period (this will never be observed in the queen since there is no vulvar discharge during the season): this is often related to the blood that accumulated in the vaginal during the season, but it should not last long (2-3 days usually). After that, the only other discharge you should observed in bitches and queens will then be at the time of parturition and corresponds to the placentas expulsion. Anything else is considered abnormal. Anything else required a veterinary consultation. Sole exception to that rule: clear transparent vulvar discharge, which can be observed from time to time. This is vaginal mucus and even if it is not enough to confirm gestation in a breeding animal, it is usually in my experience a very good sign that the animal is pregnant.But again, this is the ONLY exception.
Why consulting a veterinarian?
There are only two potential origins for this discharge:
– The vagina: we can indeed observe such clinical signs in case of a vaginitis, an inflammation of the vagina. This is not uncommon in bitches because of their specific anatomy (the vagina is very long, with lots of folds inside which liquid can accumulate during the season and favor bacterial growth and therefore vaginal infection), but pretty rare in queens (shorter vagina, no discharge during the season). The prognosis for this kind of disorder is usually pretty good.
– The uterus: this discharge can be related to the development of a pyometra (=pus in the uterus). This disease can be life-threatening.
Unfortunately you have no way to make the difference between the two just based on clinical signs. For sure on the long run, clinical signs of pyometra will become more severe (lethargy, vomiting, diarrhea,…). Keep in mind that the first thing that vulvar discharge is usually the first thing breeders will observe. And very often, apart from that, everything looks normal during the first stages of the disease. That is why you need to seek for a veterinary consultation. Thanks to the development of ultrasounds and vaginal endoscopy it is now possible to clearly diagnose what is going on. And the sooner an appropriate treatment is started, the better the prognosis for the animal and for its reproductive career.