Yes he definitely needs a friend.
Two piggies must have character compatibility to form a long lasting bond. They will not eat each others testicles, but incompatible piggies won’t bond and they will fight.
He does desperately need a friend though but if you are carrying out an on spec bonding (ie going out and buying another piggy without the ability to do any character matching), then you do need to have a plan b for living arrangements. Bonding babies can be easier (as they are both desperate for company so are more likely to take to each other) but it isn’t a guarantee, and it also isn’t a guarantee that incompatibilities won’t come to light when the teens and hormones hit (ie if they both end up being dominant then that is when bonds fail) (they are hormonal teenagers between the ages is 4 and 14 months). It’s not something you should let worry you (he really does need a friend), most boar pairs are ok, but it’s about keeping that back up plan in mind when it’s on spec bonding.
Being from the same litter does not guarantee a successful bond.
Being the same age can bring issues as they will both be going through the height of hormones at the same. (There is actually benefit in bonding him with an adult - an adult won’t he hormonal and they can teach a baby how to be a guinea pig).
Ensure the bonding is done on neutral territory. You cannot just put the new piggy directly into his cage as it will cause fights. I’ve attached the bonding guide which explains the full process.
Ensure their permanent cage is 70x24 inches (180x60cm). Boars are territorial and need a lot of space - lack or cage space can be a reason for tensions.
Also ensure you provide multiple resources in the cage - two bottles, two hay piles. Don’t use food bowls and instead scatter feed veg and their one tablespoon of pellets each directly into loose hay piles. This encourages foraging and mental stimulation but also means one pig cannot food hog.
Ensure you have several hides in the cage and ensure all have two exits. Don’t use any hides with only one way out as one pig can trap the other inside and that is when fights and wounds and occur.
My recent piggies have all been boars. The eldest pair were happily together for their whole lives. I then have another pair, sadly their bond failed when they were 18 weeks old and they have to live separately. When the first of the eldest pair passed away, the remaining one was successfully bonded with one of my younger single boars until he passed away. I’m now back to the two boys who fell out, they still live side by side.
I’m glad you are keeping him as your personal pet.
We as a forum are highly against piggies being classroom pets as it goes against everything they need and causes them to be highly stressed.
I’ve added lots of guides below to help with the bonding process and care information
1 Introduction
2 Pre-bonding
- Quarantine and sexing
- The need for a plan B
- The rule-breaker: Youngsters under 4 months (sub-teenage)
3 Setting up an introduction
- Getting to know each other
- ‘Buddy baths’ – why not
- Scent swapping - why not
- Setting up a neutral bonding area
- How to start the bonding
4 Acceptance phase: Do we like...
1 List of dominance behaviours in ascending order of aggression
2 What may cause this type of behaviour in boars?
3 When do you see these behaviours in sows?
4 What can trigger fall-outs?
5 Further helpful guide links
I thought it may be handy to have a sticky on typical dominance behaviours for a reference - hopefully it may help humans understand guinea pigs and their behaviour a bit more and hopefully prevent some avoidable problems!
1 List of dominance behaviours...
Contents Overview
1 What This Collection Is About
2 Guinea Pigs as Pets
- Family and Classroom Pets
- Sourcing Your Guinea Pigs, Common Pitfalls and Your Customer Rights
- Human Pet Anxiety: Practical Tips for Sufferers and Supporters
- Naming and Finding Out the Breed
- Guinea Pig Facts: An Overview
3 Living Environment
- Housing (with sourcing tips)
- Bedding (with...
1 Animals in classrooms - The official welfare stance
- How effective are classroom pets for teaching welfare and lasting respect?
- Alternative resources and inspiration for introducing animal welfare
2 Guinea pigs in classrooms - Reasons why not
- Social species in need of company of their own kind
- Ground roaming territorial species with large space needs that doesn't respond well to being moved around lots
- Prey animals who do not respond well to a...
. This will offer you absolute proof that, not only are their testicles still there, but some of our boys delight in displaying them!