Genital ultrasounds now allow us to clearly visualize what is happening at the uterine level in the breeding bitch/queen. As I previously mentioned in other posts, certainly one of the greatest tool we have today in veterinary medicine when it comes to small animal reproduction. As shown on the picture above, it allows us to detect liquid inside the uterus (under ultrasounds, liquids appear as black: “liquids” inside the uterus are circled in blue on the picture here).
Liquid in the uterus: pyometra as a first guess for sure but…
When we see this, our first guess is often pyometra (I can tell you that will be mine for sure!). Remember, pyometra = pus in the uterus and indeed, this is what it looks like under ultrasounds. However, you guys know that, as breeders, you are predisposed to encounter uncommon situations. So it is good to know that liquid in the uterus does not necessarily mean pyo and that it can sometimes be caused by something we called “mucometra”, a totally different disease.
Mucometra = mucus in the uterus. Mucus is sterile, no bacteria there and therefore, a totally different clinical expression. While in the case of pyo clinical signs will inevitably be observed (vaginal discharge for instance), mucometra most of the time will remain totally asymptomatic. That’s why mucometras are often incidental finding when we spay an older female or when this individual undergo an ultrasounds because of history of infertility…
Mucometras can be treated as well
As mentioned in one of our previous post, pyometras are always a combination of bacterial infection + hormonal impregnation. In mucometras we are missing the bacterial compound (since mucus is sterile). But we miss as well the hormonal compound. On the contrary to pyos, mucometras are often not directly related to hormonal secretions. In my experience, I was never successful treating mucometras with the medical alternatives that work so well for pyos.
We don’t know much about what causes mucometra (for sure it is not as common as pyo so data are really scarce in dogs and cats) but:
– we know that treatment can be attempted (the goal is to remove the liquid from the uterus and that is possible thanks to TECT, see my post here)
– At least in my experience, all bitches we treated this way were then able to conceive.
Mucometras are definitely not the most common uterine disease encountered in breeding bitches and queens, but as I always say, breeders are predisposed to see these rare diseases. Always good to know a bit !
DR. EMMANUEL FONTAINE 