So my guinea pig has this thing on her neck (I call it a double chin) it’s not bumpy it feels like fat What is it?
– Amber in Colorado via email
Yes, that is a photo of Buttercup the Guinea Pig, rocking her gorgeous dewlap.
In the past two months, Hammy has received a lot of questions about the mysterious “guinea pig double chin“. Perhaps it’s due to the winter weight gain that has so many guinea pig Humans wondering what is this strange chin growth they are noticing. But whatever the reason, that extra pouch of skin is not an extra “double chin”. It’s called a dewlap.
Wikipedia defines a dewlap as “a longitudinal flap of skin that hangs beneath the lower jaw or neck of many vertebrates.” In fact, dewlaps are a rather common physical characteristic in many animals: dogs, elk, rabbits, even reptiles and birds have dewlaps.
Guinea Pig Dewlaps
Guinea pigs, both male and female, typically develop dewlaps at 2 or 3 years of age, though some get them younger.
But unlike other animals, the evolutionary purpose of guinea pig dewlaps remains a mystery. In fact, The Humans could find no scientific evidence that points to the biological function of guinea pig dewlaps.
Dewlaps are a normal feature of some healthy adult guinea pigs. However, if you feel lumps or you suspect your guinea pig is over-weight, please schedule a veterinary appointment immediately.
So there are many unanswered questions when it comes to the purpose of this curious feature of guinea pigs. What could be their purpose?
Are guinea pig dewlaps used as a way of attracting members of the opposite sex during courtship, like lizards?
Or perhaps, like rabbits, the guinea pig dewlap is used as a sort of portable nesting reserve, allowing rabbit females to pull fur from their dewlaps to create soft and warm nesting beds for their young.
Curious, indeed!
Whatever the reason, for now this little curiosity of the guinea pig community remains a mystery.
What’s That Dewlap For
Does your guinea pig have a dewlap? If so, how big is it? And at what age did your guinea pig start getting some noticeable chin chub?
We’d love to hear what you have to say!
My girls are only just 2 and both have had dewlaps for at least 6 months. Esme’s is much bigger than Ruth’s, which makes sense as she’s the heavier pig, but neither of them are overweight and they’re both active, so I try not to let it worry me!
This is the greatest blog, thanks for all the great info. As a new Pig owner I want to do all the right things for Snowball.
Thanks for caring for Snowball, Human! Glad we’re here to help 🙂
all my guineas have dewlaps, good to now know what they are called but shame no one knows what they are for. they developed them at about 2 years I think. our old guinea that has died now did have a big lump in hers tho so I like to check my other guineas for lumps now and then just in case
Good advice – you never know where lumps may hide. Thanks for the reminder, Emma! 🙂
I’ve had Sparky for 6 months and he rarely sings (wheeks a little when I pick him up). I’m wondering if overfeeding contributes to such behavior (I keep his pellet dish topped of, though he usually ignores both it and his water bottle in favor of his favorite–fresh parsley).
My baby guinea pig Angel has developed a dewcap. She is almost 6 months old. She is a very healthy and happy piggie My husband was asking me what it was and of course I didn’t know. I did check her for a lump and there was none. She however did not like me messing with it. Got a little fussy.
My youngest pig, Sid, who is 9 months, has a dewlap that I noticed last night during floor time. He is quite portly, but also very active.