Floppy ears in dogs are quite an invention! They are a defining characteristic of many dog breeds and despite their simple appearance, they hold various important functions. Need some examples? They are critical for communication, hearing ability, and health.
The presence of floppy ears is often associated with selective breeding and domestication, a phenomenon seen in studies like the famous farm fox experiment. If this is new to you, read on to discover more about this intriguing experiment.
So let’s take a closer look into the physiological aspects of floppy ears in dogs and their impact on a dog’s communication and hearing.
Furthermore, we’ll explore their evolutionary origins, and how they compare to dogs with erect ears.
The Physiology of Floppy Ears
In dogs, as it happens in people, it can be said that their ear structure is for the most part composed of cartilage and muscles.
The external ear, or pinna, consists of a flexible cartilage framework that is covered with skin and fur.
What makes a dog’s floppy ears “flop?” In breeds with floppy ears, the cartilage is softer and lacks the rigidity needed to keep the pinna upright.
In contrast, dogs with erect ears have stronger ear muscles, allowing them to move their ears independently for better sound localization.
The shape and structure of a dog’s ears also influence how they funnel sound waves toward the eardrum. What’s known is that floppy-eared dogs may experience a slight reduction in directional hearing compared to their erect-eared counterparts.
However, their overall hearing ability remains always significantly higher than humans and highly functional.
The Role of Floppy Ears in Communication
Dogs use their ears extensively to communicate with both humans and other animals. In erect-eared breeds, ear positioning plays a significant role in expressing emotions such as alertness, fear, or curiosity.
For example, pricked ears often indicate attentiveness, while ears laid back against the head suggest fear.
Floppy-eared dogs, however, have a more limited range of ear mobility due to reduced ear muscle function. This can make their body language less evident compared to erect-eared dogs.
However, this doesn’t mean it’s impossible to “read them.” With my Rottweilers, I could tell when were alert. Their floppy ears were oriented towards something as their top would slightly raise and their forehead would wrinkle.
Dogs with floppy ears must therefore rely on other forms of communication, such as facial expressions, tail movement, and vocalizations.
Some floppy-eared dogs can still move their ears slightly, but their communication through ear positioning is less precise and somewhat less easy to interpret compared to dogs with erect ears.
Despite this limitation, humans and other dogs still interpret their signals effectively.
Do Floppy-Eared Dogs Hear Well?
While floppy ears may reduce directional hearing slightly, they do not significantly impair a dog’s overall ability to hear.
Dogs have an impressive auditory range, detecting sounds between 40 Hz and 60,000 Hz—far beyond human capabilities. Their inner ear structures remain unchanged regardless of ear shape, ensuring that they can hear even high-frequency sounds effectively.
However, because floppy ears cover the ear canal and may not localize sound as precisely as erect-eared dogs. Because their pinnae are less mobile, they may therefore not pinpoint sound sources as accurately as their erect-eared counterparts.
Nonetheless, they are still capable of detecting distant sounds, making them excellent companions for hunting, guarding, and companionship.
Are Floppy-Eared Dogs More Prone to Ear Infections?
Floppy ears are often believed to have an increased susceptibility to ear infections. This is because the floppy pinna covers the entrance to the ear canal, creating a warm, moist environment that is ideal for bacterial and yeast growth.
Erect-eared dogs instead are believe to have better ear ventilation, allowing air to circulate freely and reducing the likelihood of bacterial and fungal overgrowth.
However, while floppy ears do contribute to ear infections, ear structure alone isn’t the only factor at play.
For example, German Shepherds have erect ears, which should theoretically allow for better ventilation and lower infection risk, however, they are still quite prone to ear infections.
If we had to pick though a breed notorious for ear infections, Cocker Spaniels are the poster child for ear infections!
While erect-eared dogs generally have fewer ear infections due to better air circulation in the ear canal, one disadvantage is “openness.” In a nutshell, they’re more vulnerable to environmental hazards like frostbite, injuries and insect bites.
The Role of Domestication
Many wild canids, such as wolves, foxes, and coyotes have erect ears, why is that? Most likely because the presence of floppy ears in many domestic dog breeds can be attributed to domestication.
One of the most famous studies supporting this idea is the Russian farm fox experiment, conducted by Dmitry Belyaev.
In this experiment, wild foxes were selectively bred for tameness and friendliness toward humans. Over generations, these foxes began to exhibit physical traits associated with domestication, including floppy ears, shorter snouts, and piebald coats.
This phenomenon suggests that floppy ears may be a byproduct of domestication, rather than a trait specifically selected for.
The reason behind this lies in the neural crest hypothesis, which proposes that reduced levels of neural crest cells during embryonic development lead to physical changes such as floppy ears, curly tails, and reduced aggression.
The hypothesis entails that a reduction in neural crest cell proliferation and migration is a core genetic mechanism of early domestication.
Since the neural crest contributes to the development of both the nervous system and cartilage, selecting for docility inadvertently affects ear structure.
Did you know? In a study, dogs with floppy ears were rated higher on Agreeableness and Emotional Stability than pointy-eared dogs.
Comparison with Erect-Eared Dogs
Erect-eared dogs, such as German Shepherds, Huskies, and Belgian Malinois, tend to have superior directional hearing due to their ability to move their ears independently.
This gives them an advantage in activities that require acute sound detection, such as herding, hunting, and search-and-rescue work.
In contrast, floppy-eared breeds were often bred for purposes where acute hearing was less critical, such as scent tracking or companionship. Hounds, such as Beagles, Basset Hounds and Bloodhounds for example, rely more on their powerful sense of smell than their hearing when tracking scents.
Did you know? Many puppies known for boasting erect-ears (like German Shepherds or Siberian Huskies), have floppy ears as puppies because their ear cartilage is still developing. As they grow and their cartilage strengthens, their ears will start standing up.
Different Types of Floppy Ears in Dogs
Not all floppy ears are created equally! They come in different styles, following are several types of floppy ears in dogs.
Button Ears
These ears bend over at the tip. The name “button ears “derived from the appearance of this ear which somewhat resembles the buttoned fold seen on pockets on a shirt.
This ear type is seen in several dog breeds. In the pug’s breed standard, the American Kennel Club, describes the ears in this breed as being small and soft, like black velvet. Two kinds of ears are accepted – the “rose” and the “button” but preference is given to the latter.
Rose Ears
These ears look a bit erect, but then the fold drops down causing the end part of the pinna of the ear to fall to the side. Its name derives from this ear’s shape due to the folds resembling somewhat the petals of a rose.
You’ll see rose ears in a variety of dog breeds, more notoriously in several sighthounds.
Drop Ears
As the name implies, these ears are floppy. Labrador retrievers, golden retrievers, and Chesapeake Bay retrievers are just some dog breeds that are known for sporting drop ears.
Interestingly, these dog breeds share a predisposition for swimming. Therefore there may be chances those drop ears were selectively bred for to prevent water from entering the ears, explains Christine Zink in the book “Peak Performance EBook: Coaching the Canine Athlete.”
There are several other dog breeds known for featuring drop ears.
Filbert Ears
This floppy ears shape is specific to only Bedlington Terriers. This ear is triangular in shape with rounded tips and is velvety in texture. Its most characteristic trait is the small silky tassel found at the tip. The name of this ear derives from the word “filbert” which depicts a nut of the hazel family.
Folded Ears
This an extreme form of the drop ear characterized by very long ears that hang down a lot and have distinct folds. Also known as pendulous ears, these ears touch the ground as often seen in the blood hound and basset hound. This type of ear is characteristic of dogs selectively bred for tracking.
The Power of Pendulous Ears
In dog breeds with long ears such as Basset hounds and Bloodhounds, the ears carry several intriguing additional functions.
Because these dog’s ears are so low to the ground, especially when their heads are lowered during scent tracking, they stir up scent particles from the ground, helping direct them toward the nose.
This, along with the loose, wrinkled skin, helps create “a scent pool” around the nose, allowing for more thorough olfactory processing and a higher likelihood of accurately following a scent trail.
Furthermore, the long ears also act as a barrier, helping block noise and wind disturbances that may distract and disrupt the scent trail.
Concluding Thoughts
As seen, floppy ears are fascinating! They are a great representation of how evolution, domestication, and selective breeding have shaped the canines we live with today.
While they may appear to be just a charming trait, their structure serves various functional purposes, from enhancing scent-tracking abilities to keeping ears somewhat protected from water.
Whether aiding in tracking, protecting against environmental factors, or simply making dogs appear more approachable, floppy ears are more than just a feature, they’re a testament to the complex and remarkable nature of canine evolution.
References
Fratkin, Jamie & Baker, Suzanne. (2013). The Role of Coat Color and Ear Shape on the Perception of Personality in Dogs. Anthrozoos: A Multidisciplinary Journal of The Interactions of People & Animals
Waller BM, Peirce K, Caeiro CC, Scheider L, Burrows AM, McCune S, Kaminski J. Paedomorphic facial expressions give dogs a selective advantage. PLoS ONE. 2013
Dugatkin, Lee. (2018). The silver fox domestication experiment. Evolution: Education and Outreach
Trut LN. Early canid domestication: the farm-fox experiment. Am Sci. 1999
Wilkins, Adam & Wrangham, Richard & Fitch, W. (2021). The neural crest/domestication syndrome hypothesis, explained: reply to Johnsson, Henriksen, and Wright. Genetics