What is a Dewlap? The Curious Case of the Unusual Double-Chin Rabbit

Check out the dewlap on that bunny, it’s HUGE!

If you are new to the world of rabbits and don’t know what a dewlap is yet, then congratulations! You’re in for an interesting journey.

A dewlap is a flap of skin that hangs from under the chin of some breeds of domestic rabbits. It’s mostly found in females but can occur in males as well. It can range in size from small bumps to large sacks depending on the breed type. They often have different colors such as white or brown and they vary in length too with some being more than 2 inches long while others barely visible at all due to their fur covering them up most of the time.

You don’t always see these but there’s an acceptance in research that it exists in all types of rabbits but some are more prevalent than others. And again, it’s just speculation.

But you might be wondering, what’s the point of these extra features? What do they do? Do they play some type of role in the survival of a rabbit species? Or are they simply vestigial parts of a domesticated rabbit that has been long since forgotten and useless?

Let’s dive into the juicy details along with some speculation.

What are the characteristics of a rabbit with a dewlap?

Dewlaps actually look like a rabbit’s double chin. You can even call it a chin pillow. It’s an extra layer of fold that hangs just under their jaw.

Rabbit with a medium sized dewlap
Rabbit with a medium sized dewlap

Most of the time, the smaller version of dewlaps is difficult to notice. You could find the extra loose skin if you feel for it but as far as visually looking for it, that would be another story.

Larger dewlaps actually take the form of what you’d describe as a pillow around their necks.

In most situations, you’ll likely find the female species to have dewlaps. However, it is possible for a male rabbit to have a dewlap as well. So you can’t determine the sex simply by looking at the dewlap alone. It’s just not as common in males compared to females.

Dewlaps can also be found to occur more often in larger breeds of rabbits. These are giant-sized rabbits that sometimes weigh as much as 11 pounds or more and include the checkered giant, continental giant, flemish giant, and more.

These breeds tend to have the most pronounced dewlap displays.

As often as you’ll see dewlaps in larger rabbit breeds, you’ll still be able to catch a few smaller breeds with dewlaps.

You may also find that dewlaps are prevalent in breeds of lop-eared rabbits. These rabbits have large, floppy ears. But again, statistics show that the female species tend to display dewlaps more than the male species.

Dewlaps seem to be more common in rabbits with looser skin such as the lop-eared and the flemish breeds.

What is a dewlap for?

It is often understood that female rabbits are not particularly born with large dewlaps. As they make it to adulthood they begin to develop dewlaps. This is especially true come a time when the female is ready to have babies.

There’s no evidence of why dewlaps exist and why they develop especially during times of breeding.

Studies have not shown dewlaps to be attractive to the male counterpart. Thus concluding that it provides no distinct advantage to mating.

There are two theories that are circulating the air at the moment as to why dewlaps exist and why they are mostly found in female rabbits.

The first one is when a rabbit is pregnant and building a nest underground for its future babies. These female rabbits will remove their own fur to add to the nest.

In most cases, this is a normal occurrence. Female rabbits will often pluck out some of their own fur from different areas of the body just to add building material to the nest.

You may even find this behavior in rabbits that are not pregnant but in heat. Your rabbit may start building a nest with bits of her own fur even if it’s not pregnant. It could be due to it preparing to mate and get pregnant even though you don’t plan to introduce her to a male to do so. This is normal.

However, if you find your rabbit is removing such an amount that leaves large areas of your rabbit bald, then you should consult with a veterinarian about the matter.

Another theory about the dewlap comes from the observation of a mother rabbit which explains the origins of the word.

As a mother sits over and protects her young from predators and the elements, she will sometimes climb her way to the outer edge of the hole, lay her dewlap down, and set her chin on top as a pillow.

As it rains, the dewlap will gain moisture and if it’s big enough, it will pocket a small puddle for the mother rabbit to drink from. This is how the term was coined. It was considered a “lap” that catches “dew.”

Or at least that’s what they say.

Do all rabbits have a dewlap?

In essence, all rabbits do have the genetic ability to form a dewlap. However, dewlaps are more prevalent in some breeds than others and it is even more obvious in females over males.

Whenever a male rabbit starts to gain weight, the chin begins to build up this fatty tissue right under the jawline and neck. The fat begins to build up and be elastic skin begins to form a dewlap.

So yes, dewlaps do exist in the male species of rabbits but it is more obvious when they are overweight. Hence, which is why you’ll oftentimes see dewlaps in the larger breeds of rabbits.

What kinds of rabbits have dewlaps?

It is so much more common to find dewlaps in larger breeds of rabbits.

You can find dewlaps in breeds such as the:

  • Belgian hare
  • Flemish giants
  • Californians
  • French lops

Are rabbits born with dewlaps or can they develop it over time?

Typically, there are actual proteins inside a rabbit’s DNA that will control the elasticity of its skin. This protein is associated with a few diseases. However, it appears to be the fundamental cause of rabbits developing dewlaps.

Rabbits are, therefore, born with this genetic trait and it does develop into a larger form as they develop and age.

In other cases, diet and exercise is also a contributing factor in the size that a dewlap develops into. Yes, the larger and more overweight a rabbit becomes, the more fat seems to deposit itself into the furry patch it creates.

As the female rabbit begins to age into puberty and begins the process of motherhood, the area under her chin begins to grow larger as well. This is very common for female rabbits in this state.

A lot of the reason is theorized and linked to helping the mother build its nest using its fur as a component of the nest.

It’s important to note that even with all the observed factors like size, weight, breed, and maturity, some rabbits (both male and females) don’t exhibit dewlap features.

Some people have ignored the correlation of weight being a factor to how dewlaps develop. They claimed that they’ve known overweight rabbits with very small dewlaps. So being overweight may have a little bit of a hand in how big dewlaps get, and it doesn’t determine it completely.

But then again, the verdict is still in the air.

How big can a dewlap get?

Dewlaps can vary a lot in size between different rabbits. Dewlaps have been thought to not exist in some rabbits but only because it was so small that most of its fur was covering it.

Then you have rabbit dewlaps that were considered to have dewlap sizes of the medium variety. These dewlaps usually didn’t show any signs of being there until they were about a year old.

Then you have rabbits with dewlaps that are considered to be large in size, which is usually around the age of three years old or older. These can sometimes show up as early as six months.

The final size of a dewlap really depends on the rabbit’s genetics.

Genetics has such an influence that it can make the dewlap very small all the way to as large as a pillow flap that the rabbit can rest its head on.

Again, dewlaps have been observed to be linked to weight and sexual maturity as well. The heavier a rabbit and the more aged it is, the larger its dewlap tends to become.

Can a rabbit’s dewlap become too big?

It is actually perfectly normal to have a dewlap for a rabbit. But always remember, that if you find a dewlap that is way too big or obstructing the rabbit’s range of motion, then that would be something I would be concerned about.

Dewlaps that are very large may impede a rabbit’s normal day-to-day routine. You might see your rabbit not being able to groom itself because of such a large dewlap. You might have to take it upon yourself as a responsibility to help your rabbit with these extra routines.

If your rabbit has an extremely large dewlap, it might even get in the way of the rabbit while it is eating or drinking. It may also be at risk to get dirty over the food that it’s eating and the water that is drinking.

This can be a health concern for the rabbit if its dewlap gets dirty and doesn’t get cleaned. It could result in skin irritations, redness, and soreness in that area.

It might even be better if you purchased one of those upside-down water bottle feeders. It might also help to increase the height of the bowl that the rabbit is eating out of so that its dewlap does not end up picking up crumbs and debris from the food.

Again, there is actually a strong possibility that weight is correlated or at least slightly linked to the size of a dewlap. And being overweight does not help much either. It has been observed that larger rabbits that are overweight do have larger-sized dewlaps.

It may actually be time to adjust your rabbit’s diet through healthier eating and exercise.

Why are female rabbits more prone to dewlaps than males?

It is also understood, that dewlaps correspond with higher estrogen levels which may explain why it is not clearly visible in male rabbits. Nevertheless, it seems to exist in variable sizes and can develop in any rabbit.

In evidence of this, when rabbits have been neutered, during and after puberty there is a less likely chance that they will develop a dewlap.

It ultimately seems that one of the real factors deciding the size of a dewlap really depends on the estrogen levels of the rabbit.

Estrogen is a hormone found in females of various mammalian species.

It is mostly found in the ovaries, uterus, and placenta but it has also been discovered that estrogen can be stored in fat tissue as well. This may explain why dewlaps are more prevalent in female rabbits than males because they have higher levels of this hormone which consequently allows them to develop a larger dewlap as a result.

When is a male rabbit is neutered, estrogen levels will decrease and the male rabbit will no longer have a dewlap.

This is because when neutered, estrogen levels are decreased which usually leads to less fat stored in this particular area of their body as well. For these reasons, it seems that one of the real factors deciding the size of a dewlap really depends on the estrogen levels of the rabbit.

Watch out for the dreaded wet dewlap

I want to warn people who own rabbits with dewlaps to watch out for a condition known as a wet dewlap. It’s better known in the medical field as moist dermatitis.

It is a condition that is caused by the rabbit licking its skin too much.

It creates a moist, raw spot on their neck and leaves them with something that’s very sore to touch.

What are the causes of a wet dewlap?

The reason for this condition can vary but in most cases, it will usually be due to the following:

  • Water drinking from a bowl gets the dewlap wet every time your rabbit drinks
  • Unsanitary living conditions
  • Drooling and salivation
  • Constantly licking the dewlap skin

Since dewlaps are primarily located close to the chin, it’s possible for it to be constantly wet which will eventually cause a sore to develop.

Rabbits don’t know that they should avoid getting their dewlap wet so try to keep it dry as much as possible.

Studies have also shown that irritation in teeth or dental disease may cause a rabbit to salivate more often than usual which may lead to wet dewlap if it has a large enough dewlap to capture that moisture.

In these cases, you’ll find that the area of the dewlap begins to look like a red or pink sore that can be seen through the fur. If left alone without any resolution, it can turn green and infected.

How do you treat a wet dewlap?

You must treat the condition early on to prevent it from getting worse.

The best way to treat a wet dewlap is by cleaning the area thoroughly with warm water and using an antiseptic solution or ointment twice daily, for at least two weeks.

If the rabbit’s chin gets wet from saliva, you’ll need to keep a towel handy and clean it up with warm water.

You can use a hairdryer if your pet has one at home or wrap them in a towel for ten minutes to make sure they are completely dried off.

This condition can be hard to resolve because rabbits don’t like having their chin touched and are very sensitive around that area.

If it progresses to the point of infection you will need to visit the veterinarian which will provide the necessary antibiotics.

Ways to prevent a wet dewlap

The best way to prevent these infections is:

  • Make sure the rabbit area is nice and dry.
  • Remove excess hair from your rabbit’s dewlap and groom it regularly so that if it gets wet, it will dry faster.
  • Make sure to use bottled water with droppers and make sure it doesn’t leak on its own.
  • Clean your rabbit’s teeth regularly and allow it a chew toy to avoid teeth irritation.

If all else fails, be sure to consult with a veterinarian on what procedures need to be taken to help solve this issue.

Does a dewlap go away?

In all most cases a dewlap doesn’t reduce in size on its own. However, it will stop getting bigger after a certain point.

The only other reasonable way to lessen the size is through regular diet and exercise.

Dewlaps have been seen as a sign of good health and breeding potential for some time in domesticated rabbits, but are now being discouraged by many breeders due to the recently appreciated dangers associated with them. It is still debated among rabbit enthusiasts whether dewlaps should be bred out or not.

While there are several advantages to having a dewlap, I’ve just explained to you some of the disadvantages. In most cases, grooming your bunny regularly should help prevent problems from occurring. In some extreme cases, if the dewlap becomes too big, the rabbit may need to undergo surgery.

I recommend you speak to your veterinarian about what’s the best course of action to help your rabbit.

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Author: John