
In some breeds of dog this gland is non-functioning or completely absent. In others, the gland may still prove active, though significantly reduced in size. The reason for some dogs having the gland, while others do not, is not entirely understood. It has been speculated that dogs who live their lives outdoors, for example in a large working kennel, often more frequently have functioning scent glands. Whereas dogs who have lived their lives primarily as indoor pets often do not. Though not a proven hypothesis it is an interesting theory as to why some dogs may still have an active scent gland, while others do not.