It is believed that these sweat secretions produce an individual odor signal that is recognizable by other dogs.
When these glands are active, they leave the nose and paw pads slightly moist and help these specialized skin features maintain their functional properties.
Micro-organisms live naturally in this material and give the ears a characteristic slightly yeasty odor, even when healthy.
It is not uncommon for a veterinarian to sniff a dog's ears to try to detect any potential bacterial or fungal infection.
It is thought that this secretion leaves a signal to other dogs allowing them to recognize the source of the individual fecal deposit.
This odor is also likely the signal being sampled when strange dogs investigate one another by sniffing out the anal area.
Dogs' anal glands can become swollen and unable to drain naturally, sometimes requiring a visit to the veterinarian or groomer to express the built up liquid.
Another source of natural odor results from a common dog behavior: rolling in and marking themselves with the feces of other animals in their environment.
Poor grooming of dogs with long, thick or corded hair can cause the haircoat to be a source of unpleasant odor.
Dental calculus harbors numerous bacteria which produce odor and foul breath.