I’m not sure what my piggies gender is?

[iamlexi]

Hello! SO, I got a New Guinea pig and ever since getting chewy ... The cage has been a little wild! One of my piggies, Oreo, is getting preeeeetty chunky looking! Like .. I feed them all the same amount, I give them all the same amount of treats .. and she just looks to be gaining so much more weight! Well, my mom has caught chewy mounting Oreo a few times but I’ve never caught it happening.. So, I need some help identifying what the gender of chewy is ! If it turns out the pet store sold me a male rather than a female, like they said ! I’m gonna take Oreo to the vet for an ultrasound..

 

[anyar.dris]

It looks like a sow. Mounting is also a normal behaviour with sows, especially when they are in season or they are showing dominance.

 

[Wiebke]

Hello! SO, I got a New Guinea pig and ever since getting chewy ... The cage has been a little wild! One of my piggies, Oreo, is getting preeeeetty chunky looking! Like .. I feed them all the same amount, I give them all the same amount of treats .. and she just looks to be gaining so much more weight! Well, my mom has caught chewy mounting Oreo a few times but I’ve never caught it happening.. So, I need some help identifying what the gender of chewy is ! If it turns out the pet store sold me a male rather than a female, like they said ! I’m gonna take Oreo to the vet for an ultrasound..

Hi and welcome!

How long have you had your guinea pigs and how old are they?

Sows do mount each other when they experience a strong season, so mounting is no indication of gender. But it tends to throw new owners! Here is more information on sow behaviours:
https://www.theguineapigforum.co.uk...lth-problems-including-ovarian-cysts.167978/~
When Sows Experience A Strong Season (videos)

It looks to me rather like you have got two sows but we always ask our members to please conduct a hands-on check at home as sexing from pictures has got its limits. Unfortunately, we cannot do the hands-on double-check by looking at the much clearer but less visible places ourselves (which is something we always do with our own piggies to make sure as the outwards appearance is often not as clear as you'd like).
On the other hand, learning how to sex guinea pigs reliably yourself is not the worst of life skills to acquire...

Please click on our sexing guide link and follow the tips for how to check for the presence/absence of a penis shaft just underneath the skin above the knob and for the presence/absence of a fleshy seal just below the rim in the slit below the know. Sows don't have a small penis bump but they have a fleshy seal - the difference is quite considerable, as you can see in the reference slit pictures in the guide.
Here is the link. If necessary ask your mother to help: Illustrated Sexing Guide

There is however the possibility that you have bought an already pregnant pet shop sow if you have had your girls for less than 10 weeks. We can only help you in that respect if you give us more background information. Guinea pigs don't grow evenly; they can look a some point rather fat and the next week very long. They can also differ in size quite enormously. Unfortunately, diagnosing a pregnancy from a picture is another thing that we don't do on principle as we have seen too many wrong guesses over the years without being able to have a feel.

Please take the time to read these two links. The first contains advice on your customer rights and the second contains our comprehensive pregnancy, birth, baby and mother care information, which we have specifically written for owners without previous experience. The guides are as step-by-step and practical as we have been able to make them in order to talk you through the whole period.
New guinea pigs: Sexing, vet checks&customer rights, URI, ringworm and parasites
Pregnancy, Mother & Baby Care Guides