Rabbits’ anal scent glands are located in deep vents (skin folds) to the sides of the genitals. In young, active rabbits, these glands are usually clean, but in older, disabled, less mobile or indoor rabbits, these vents can become clogged, leading to other issues.

What is it used for and how do they work?
Each little gland secretes a musky smelling odour that rabbits use to mark their territory and gives their identity. Much like dogs that sniff each other’s buts, each rabbit has a specific smell, and it has been observed that introducing new rabbits in groups can also have them sniff each other’s bottoms, but be careful: this is usually followed by a sharp, harmful bite. When rabbits spray urine, these glands also secrete their matter that goes into the wee to help them mark their territory, and rabbits will also secrete and then go and sit down so the musky liquid can go onto the grass or vegetation (outdoor rabbits) or the carpets and blankets (indoor rabbits).
Rabbits (healthy rabbits talked of here) also use this scent to mark a trail that they can follow their path back home, when they go exploring. When a rabbit has clogged scent glands or vents, they cannot mark their path and find their way back home. Blind rabbits can use this trail they map out with scent, to be able to explore safely and quickly find their way to safety should they feel threatened, and this can cause people to not realize how their bunnies are struggling with sight.

The importance of maintaining the scent glands : when the scent glands get clogged, meaning the ex reted scent does not go out, a hard brownish stinky form is shaped, and when it fills the vent it can be really bad for the rabbit:
1) it can form sharp edges, causing pain and even stasis (stop eating). It was observed that about 10% of low grade stasis cases were due to the pain and discomfort from clogged vents.
2) They are not able to map their way
3) they smell more. Many times when owners say their rabbits stink, it is because of clogged vents, giving off this musky smell.

Why clean before bonding?
When the vets are clogged, the rabbit gives off a permanent territorial smell, as they themselves smell, and not the terrain they wanted to map. This causes the other rabbit(s) they are introduced to, to go into defence, as they basically say “do not come close, you invade my space” and when rabbits are introduced in bonding, neutrality of space is the most important factor to have in mind. Thus, introducing a bunny with clogged vents, is setting up for bonding failure.

Older and sterilized rabbits secrete less marking substance, but still do. It’s part of being a rabbit, to map their path, area and territory.

What does it tell you if they get dirty fast?
Rabbits usually clean their marking scent glands to a degree by bathing, or when eating their cecotrophs (bummelgum). It is natural to have some brownish fluid and bits in the vent, however, when the vent is clogged and the secretions form a hard plug, it can show a loss in back mobility, arthritis, spondylosis, or then rabbits being overweight.

How often should these glands be checked and cleaned?
You do not want to overclean them, as they are needed to have natural oils and non-irritated skin to do their job correctly. It was found checking and cleaning every 2 months in healthy, mobile rabbits, but either 6 or 4 weeks in rabbits with back issues, or other issues causing them to clog faster. As said, clogged vents can cause sharp points on the secreted plug that can even cause stasis when it sticks into their soft skin, like a thorn.

My rabbit(s) are safe indoors, should we clean the vents more?
No, as your rabbit should have free roaming areas, if not permanent, then in playtime, and still mark their paths.

One of the most important points: when your rabbit gets out.. escapes. If your rabbit has clogged vents, they cannot secrete and map the way they go, to be able to come home again. It’s because of these secretions and glands that rabbits “know their way” and “find their way” if the vents are clogged, the secretions do not get out, to mark, and thus the rabbits find their way.

So, why do outside and feral rabbits struggle less with dirty vents? They wipe their bottoms on the grass more, which automatically helps clean the vents.

Check by physically opening the areas next to (to the sides) the genitalia, and if you see the dark brown plug…

Put on your mask… get the earbuds out, wet them with lukewarm water, and roll out those clogs.