By Kyle P.
November 10th, 2023
Bonding Guinea Pigs
Why Bond?
Guinea pigs should always live with at least one other guinea pig unless they are being isolated for medical reasons or are truly aggressive (which is a very rare phenomenon). While some guinea pigs may seem perfectly happy alone, having a buddy can increase their physical activity, enrich their life, and help them feel more secure with safety in numbers. Having the right companion will significantly improve a guinea pig’s life significantly. Human interaction will never replace a guinea pig’s bond with another guinea pig. While guinea pigs may enjoy a human’s presence, we communicate and interact with others extremely differently than they do.
Guinea pigs also may need to be rebonded after an extended time apart, such as a medical quarantine. Just because they were bonded before does not mean they will still get along after time apart.
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Can Different Species Be Friends?
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Interaction with other species of animals is also not a replacement for a same-species buddy, and can even be dangerous. Dogs and cats are large predatory animals that have the capacity to severely injure or kill guinea pigs. Even if they are peaceful and well-behaved pets, both have a natural prey drive that can be triggered by the presence of guinea pigs at any time - even if they have interacted safely before. Despite having similar care requirements, rabbits are also unsuitable buddies for guinea pigs. They are much larger than guinea pigs, and due to their movement style, they can easily accidentally injure a guinea pig with their strong hind legs.
Along with the physical dangers, dogs, cats, rats, and rabbits are considered carriers of Bordetella bronchispetica, which is one of the main causes of “kennel cough”. These animals can be asymptomatic carriers, so even if your other pet is vaccinated and healthy, they still pose a risk to your guinea pigs. Transmission of B. bronchispetica can happen through physical contact but is primarily airborne, so these animals should not even share a room with guinea pigs.
Many cats carry another bacteria called Pasteurella multocida. This bacteria is a natural part of a cat’s oral flora and can also be found in their claws and on their fur due to how cats self-groom themselves. P. multocida is the bacteria known for wiping out bird species when cats are allowed outdoors, and can also infect guinea pigs if the cat licks, touches, or scratches your guinea pigs. P. multocida is also known to be found in the mouths of dogs, but at a lower rate than it is found in cats.
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Pairings and Groupings
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While all guinea pigs should have a buddy, some groupings work out better than others.
Groupings that can work
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Two or more females
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Two males
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A neutered male and any number of females
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An intact male and any number of spayed females¹
Groupings that cannot work
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Intact pigs of opposite sexes
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Three or more males²
¹Spays are invasive and more dangerous than male neuters. When given a choice, neuter the male instead of spaying the female
²Some people manage male groups of 3+ but it is rarely successful. Do not attempt unless you are able to adopt a fourth guinea pig and keep two separate pairs
Quarantine
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Before beginning the bonding process, your new guinea pig needs to be quarantined in a separate room from your guinea pig(s) with no shared items for 14 days. You should also take your new guinea pig(s) to an exotic vet before the quarantine is over to get a general physical exam. Keep in mind that a physical exam coming back healthy does not mean the rest of the quarantine can be skipped, as not all illnesses show up physically immediately. It is okay to use a cage smaller than the required minimum as this is just a temporary situation, however if possible it is always good to give the guinea pig the most space you can.
Quarantine is important to prevent the new guinea pig from bringing diseases into your home and spreading it to the guinea pig(s) you already have. As prey animals, guinea pigs naturally hide signs of illness to keep themselves safe from predators, so people adopting out their guinea pig(s) may not always notice these signs. Some small animal rescues will do quarantines or frequent health checks before adopting out, which may mean you can reduce quarantine time.
During the quarantine, you should double-check your new guinea pig’s sex, monitor their feces and urination, listen to their breathing, monitor their eating, and observe their behavior. The quarantine period also allows you to transition pellet brands if needed and allow the guinea pig to decompress and get used to you.
Quarantines are also sometimes done for medical reasons, such as if they have a contagious disease or are recovering from a medical procedure. Some medical quarantines will allow the guinea pigs to stay in the same room, as there is no possibility of airborne transmission. Ask your cavy-savvy exotic vet for advice about your specific situation.
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How to Bond Your Guinea Pigs
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After quarantine, some people choose to place their guinea pigs in neighboring cages for a few days or longer, allowing them to familiarize with each other through the bars. This is an optional step, but many people have reported finding it helpful for boars and guinea pigs who have a history of failed bonds. If you choose to do this, do not place your guinea pigs together for “playdates”; they should only come into direct contact when you are ready for the official bonding session.
The first necessary step to bonding is to set up a neutral territory. This needs to be a space equal to or larger than their bare minimum cage space, but it cannot be one of their cages due to guinea pigs’ territorial behavior. You should scatter hay throughout the area, but that is all that needs to be in this space. Some people choose to add hideys as well, but they must have two or more entrances/exits to prevent the guinea pigs from cornering each other. Hideys are not recommended for more difficult bonding sessions such as boars, larger groups, or guinea pigs with a history of failed bonds.
The next step is to place your guinea pigs in the neutral area. They will begin to interact and express dominance behaviors. Dominance behaviors include teeth chattering, “rumblestrutting” (a deep rumble noise accompanied by a strange walk, most commonly seen in boars), chasing, mounting, and puffed-up fur. See the “further reading” section at the bottom of this article for a visual representation of these behaviors! Dominance behaviors can look intimidating and scary, and it’s normal to be worried about your pet’s safety. However, it is important not to intervene with a guinea pig bonding session unless they start to fight (see “fighting” section). If you intervene with a bonding session when it isn’t necessary, you may cause the session to fail or be prolonged. Bonding can take a long time, sometimes hours. Choose a time when you are free for most of the day. Never leave a bonding session unsupervised; if you need to step away for just a moment, make sure someone trustworthy can watch over them.
If the bond is successful, your guinea pigs will eventually stop showing dominance behavior and seem to ignore each other, often just eating hay side-by-side. Once they have been together for around 30 minutes or more with no dominance behavior, it is safe to conclude the bonding session and move them to their permanent cage. If a guinea pig previously lived in this cage, make sure to deep clean it by switching the bedding and washing fabrics. More dominance behaviors may occur after moving to the clean cage, but it should be at a much lesser scale than during the first introduction.
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Strategies to Avoid
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There are many strategies for bonding that are recommended by various people but are not ideal. Some people do have success with these strategies, but it is generally less common or works but is much more stressful and difficult for the guinea pigs involved. Keep in mind that some people may also recommend bonding strategies used for rabbits. Guinea pigs and rabbits have very similar general care but very different interactions with animals of the same species. Do not use rabbit bonding strategies with guinea pigs or vice versa.
Putting them in the same cage
Placing guinea pigs in a cage together with no bonding session will cause a territorial response, and they will almost always fight.
“Speed dating”
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“Speed dating” bonding is when two guinea pigs are placed in a neutral space for a short period of time (such as 20 minutes), and separated if they don’t bond in this time. This is more common at rescues and is usually done with guinea pigs being introduced to many different guinea pigs in one day, often in quick succession. This does not allow guinea pigs to properly express dominance behaviors and sort out their dominance hierarchy. This method is extremely stressful for the guinea pigs, as bonding is a stressful experience and meeting many different guinea pigs right after each other will add to that stress.
Bathtime bonding (and other trauma bonding)
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Trauma bonding is a strategy intended to make the guinea pigs stressed and afraid while together in hopes of helping them forget their dominance issues. While this may work, it causes unneeded and at times cruel stress on the animals. Bathtime bonding (where the guinea pigs are given a bath together) is one of the most popular forms of trauma bonding. Along with the stress bathtime may inflict on guinea pigs, baths are not recommended unless absolutely necessary. Baths strip guinea pigs’ fur and skin of natural oils and can result in dry and cracked skin, or even cause respiratory infections.
Large group bonding
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Large group bonding is when many guinea pigs who have not met before are placed into a large space, and the ones that get along the best out of the group are paired up. This strategy, especially if done with males, can quickly cause immense amounts of stress and lead to a lot of fighting. It is important to be able to observe guinea pigs’ body language during bonding, so if there are many guinea pigs all expressing dominance behaviors and challenging each other, it may be easy to miss signs of fighting or know who is getting injured. This term does not refer to a larger group all being bonded with a new guinea pig. That is generally fine, as long as it is a compatible group (however you may wish to avoid creating large herds, as it can become difficult to know if a guinea pig is refusing to eat, getting picked on, or showing signs of illness through feces or urination)
Car/carrier bonding
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This is when the guinea pigs are placed in a small space such as a carrier to bond and sometimes taken in the car. Placing unbonded guinea pigs in a tight space will cause them to corner each other and fight, even guinea pigs with strong bonds are known to become upset with one another in carriers at times. Bringing them in the car together is often done in hopes of stressing them out as another form of trauma bonding, which as stated above is not okay.
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Fighting
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For guinea pigs, “fighting” is when one guinea pig pulls fur or draws blood from another. If guinea pigs fight during a bonding session, they should be separated immediately and the bonding session is concluded. However, this does not mean the pair/grouping will never work out. You can try another bonding session as soon as the next day and continue trying a few more times before declaring them an incompatible match. If a grouping really seems like it won’t work out after multiple bonding attempts, it might be necessary to try a different match-up. Some rescues allow “foster to adopt”, or allow bonding sessions within the rescue before you officially adopt your new guinea pig. If you are having trouble finding the right match for your guinea pig, it may be worth looking into those options so you don’t have to adopt and return failed partners for your guinea pig(s).
Fighting can also happen within already bonded groups. If a bonded pair or group fights, they will need to be separated and go through a bonding session to help re-bond them. Causes of fighting in bonded groups can include cages that are too small, food guarding (solved by adding more food stations or scatter feeding), dominance during heat, or young guinea pigs getting older and asserting more dominance. If a guinea pig becomes extremely aggressive towards its cage mates for seemingly no reason, contact your cavy-savvy exotic vet to discuss potential hormonal problems.
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Guinea Pig Loss​
A guinea pig passing away and leaving a single cagemate behind is very sad for both the owner and for the remaining animal. Guinea pigs that have lost a cagemate do need to be bonded with a new one, but it is very important that an owner allows themself to grieve as well. Remember, getting a new guinea pig is not replacing your old one, and their memory will live on with you. There are many ways to honor a late pet, such as sharing their story, keeping photos, keeping their ashes, or making prints of their feet. Allow yourself to grieve in whatever way you need to, and it’s okay to wait a short period of time to get a new guinea pig if you need to, unless your remaining guinea pig is showing signs of depression.
Signs of depression in guinea pigs include lethargy, refusal to eat, and abnormal behavior. Some abnormal behavior is normal, but if your guinea pig becomes lethargic or refuses to eat, you may need to ensure that your guinea pig is not sick and help them eat using Critical Care. Most guinea pigs will not experience depression. However, even if your guinea pig seems happy, it is still important to get them a new buddy to promote their long-term mental and physical well-being. If your late guinea pig passed away for an unknown reason, get a necropsy or take your living guinea pigs to the vet (or both!) to ensure that they did not die of a contagious disease. If multiple guinea pigs die within a short time frame and you still have living guinea pigs, take your living guinea pigs to the vet as soon as possible.
Some people prefer to get guinea pigs in groups of three, rather than two. This means that if one passes away, the remaining two will still have each other’s company. In this situation, getting another guinea pig is completely optional. Of course, this will not be possible for boar pairs.
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Further Reading
More resources on guinea pig bonding!