Puppies are born with their ears closed because puppies are an altricial species. To better understand why puppies are born with their ears closed it therefore helps to gain a closer insight into a newborn puppy's physiology and development.
Puppies are an Altricial Species
When puppies are born, they are helpless little beings that depend totally on their mothers for their care. This makes puppies an altricial species, which is in net contrast with precocial species, species who are relatively mature and mobile from the time of birth.
Newborn puppies have a relatively undeveloped brain and their bodies are unable to maintain their temperature. They totally depend on their moms to stay warm and for nourishment. Newborn puppies also depend on their mom to eliminate. Mother dog uses her tongue to stimulate them to urinate and defecate.
A newborn puppy can feel and taste and is also equipped with special sensors in his nose that allow him to detect warmth so to crawl his way towards mom and littermates. If he happens to topple over, he is capable of righting himself. If he feels hungry or cold, he will use his vocalizations to attract his mom.
Why Are Puppies Born With Their Ears Closed?
As an altricial species born in a rather primitive state, a newborn puppy cannot see or hear until he is more developed. A puppy is born with his eyes shut and his ears sealed for the simple fact that his eyes and ears are in an undeveloped state and significant harm would result from exposure to light and sound at this stage.
A puppy's ears therefore do not open until the puppy is more mature as his neural system is not ready yet for processing auditory information. Any sound in an unprotected ear at this stage would cause permanent damage.This is likely the price to pay for a dog's shortened gestation time.
Indeed, an altricial species' gestation time is quite brief compared to the gestation time seen in precocial species. Just consider that, in dogs, pregnancy lasts just an average of 58 to 63 days while in precocial animals, the gestational period is relatively long, with mares having a pregnancy that lasts on average 11 to 12 months!
The stage when puppies are blind and deaf is referred to as the neonatal stage. This stage is expected to last approximately two weeks.
When Do Puppies' Ears Open?
A puppy's eyes and ears are expected to open at around two weeks of age. There are of course individual variances from one puppy and another.
This sensory development paves the path to the transitional period which lasts until the puppy about 21 days of age. The transitional period is a time of rapid neurological development and significant changes take place a the puppy's world unveils beyond his eyes.
While the eyes upon opening are are still developing and extremely fragile, the ears are capable of allowing the puppy to hear the moment those ear canals open. Although puppies can hear at this time, those ears are expected to be fully functional roughly by 20-21 days.
During this time, it is possible to see the puppies startle upon hearing a sound. However, the good news is that at this age, puppies are very fast to recover.
As the puppies mature a bit more, it is possible to start exposing them, and therefore, habituating them to common household sounds.
"By the sixteenth day, she will be able to tell where a sound comes from, and between the fourteenth and eighteenth day she is capable of being startled from an auditory stimulus. At the end of the transitional period, the puppy will pretty much have her sensory act together."~Nicholas Dodman, Puppy's first steps: the whole-dog approach to raising a healthy, well-behaved dog.
Now That You Know...
Puppies are fascinating creatures and it's an amazing experience watching them develop and grow. If you are a breeder, now that you know when a puppy's ears open, you may be interested in the several things you can do in order to give your puppies a head start to grow accustomed to the world of humans.
- Once your puppies' ears have opened, it is beneficial to stimulate the auditory segments of your puppies' brains by exposing the puppies to soft noises.
- Playing classical music that uses various instruments at a lower than normal volume is beneficial as there are shifts in tempo and auditory changes from soft stringed instruments to the more bold percussions, points out Jerry Hope in the book "Breeder's Guide to Raising Superstar Dogs." This auditory stimulation promotes an increase in brain activity as the ears work on decoding novel sounds.
- As puppies mature, and reach the awareness period which takes place when the puppies are between 21 and 28 days of age, it is possible to start exposing them to sudden sounds, but always in a controlled manner, making sure that the pups don't get excessively stressed.
- Early exposure to a variety of sounds may help reduce the chances for the puppies to become frightened of noises.