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Dr. B.
Dr. B., Board Certified Veterinarian
Category: Vet
Satisfied Customers: 22468
Experience:  General practice veterinary surgeon with extensive experience in a wide range of species.
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I have two male guinea pigs (4 months old) shoud i get them

Customer Question

I have two male guinea pigs (4 months old) shoud i get them neutered?
Submitted: 3 years ago.
Category: Vet
Expert:  Dr. B. replied 3 years ago.

Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.

First, I must ask, are you absolutely they are both male (similar genital appearance to one another)?

How is Reggie and Ronnie's relationship? Are they getting along? Or do they fight, mount, or cause each other grief?

Customer: replied 3 years ago.

Hi Dr B,


They where sexed when I brought them and I am certain they are both males. On the whole they get on but Reggie is more domineering and does try mounting Ronnie!


I am going to register them with a vet soon and will get them to give them a health check but did wonder if gettin them neutered would calm Reggie down!


thank you

Expert:  Dr. B. replied 3 years ago.
Thank you Sue,

I am glad that you have had them sexed and are sure they are both boys (you'd be surprised how many times people don't check and end up with more guinea pigs then they started with).

Now in regards to neutering cavies, this is actually a wee bit of a controversial topic. The reason is because unlike cats/dogs, there is no proof that neutering (which is done to reduce testosterone) will reduce the territorial herd and dominance behaviors a male cavy may show. Some people have reported that the neutered lad does see calmer but generally speaking we'd not expect neutering to positively impact the social behaviors of this species.

Instead, if we have territorial/dominance issues, we tend to approach this from a view of increasing resources. This means increasing cage space, access to amenities, and spaces to get away from one another. This usually lowers the drive to dominate and claim the territory and is a more effective approach to this behavior then neutering.

Furthermore, in regards to considering the reasons we neuter in other species, we also cannot apply the reduced risk of mammary or testicular tumors as these both tend to be uncommon in this species. So, this bonus for neutering in the cat or dog, is not confirmed for cavies either.

Overall, the key to whether to neuter a guinea pig (and taking the risk of the anesthesia to do so) is based on the situation they live in. If you had a female cavy in this group, then neutering the males would be indicated (especially as it is less invasive then spaying the female). But without one, the main justification for neutering is lost. And if one is neutering in hopes of changing behavior, we'd have to appreciate that only testosterone driven behaviors (not social dynamic ones in a herd species) would be likely to respond to neutering in this species.

I hope this information is helpful.

If you need any additional information, do not hesitate to ask!

All the best,

Dr. B.


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