Did you know? Those slits on the sides of your dog's ears that resemble a small pouch are known as Henry pockets. Also known as cutaneous marginal pouch, the function of a dog's Henry pocket is not entirely known, however, there are a few theories as to why they exist.
One theory has it that they help dogs detect sounds. Without getting too technical, there may be chances that when sound waves reach the dog's eardrum some other sound waves may bounce off the ear flap causing a slight delay before impinging upon the dog's eardrum. Sound waves that happen to reach the dog's Henry Pocket, are further delayed and therefore the Henry pocket may help in attenuating lower pitches while increasing high-pitched sounds.
Another theory has it that a dog's Henry pocket is just there to help dogs flatten their ears.
Regardless of what the main function of a dog 's Henry pocket is, one thing is for sure, pesky parasites seem to love this area. Indeed, vets know well how mites and ticks like hiding in this area. So after your dog romps in the tall grass, make sure to check this area on top of in between your dog's toes, under the tail, in the armpit area, genital area and under your dog's tail.