Wednesday, January 18, 2017

How to introduce a new guinea pig

Guinea pigs; cavy; guinea pig introduction
Osler (left) and Fitzy (right) some minutes after meeting.

Guinea pigs are herd animals. They enjoy companionship and often fret when kept alone. The problem of course is that even well-kept guinea pigs die eventually, and unless that is due to an accident or natural disaster, one is left without a companion.  Thence the eternal “guinea pig chain” that those in the know speak of.

Isolated guinea pigs appear to be stressed, and may be more prone to physical illness. In my experience a lone guinea pig is less active and more flighty than one with a companion. Many publications recommend a group of three guinea pigs – two females and a neutered male. This is a species that should not be kept alone.

But how do you go about introducing another guinea pig? One has to respect that not all animals will take to each other immediately. You cannot just stick a new guinea pig into your established guinea pig’s enclosure and walk away. This can lead to fighting, wounds, secondary infections and distress. They can’t get away from their flatmates if they don’t like them.

This week we introduced a new boar, Fitzy, to Osler, an adult sow. Fitzy is three-years-old, desexed (this is imported as Osler has not produced offspring – if they don’t breed by nine months their pelvic symphysis fuses, making a caesarean necessary and these are high-mortality procedures) and had recently lost his female companion.

Here’s our policy on introducing guinea pigs:

  • Know the sex. Confession: I’m guilty of not doing this on one memorable occasion. I had a boar who was fretting, and I admit I was in a hurry. It was after work, I’d been looking all around Sydney and I found a contact who had a young “boar” to introduce to my older boar (its usually easier to introduce a younger boar to an older, established boar). I trusted that she had checked, took “him” home, introduced him to my new boar and noted they got along like a house on fire. Several days later I checked “his” sex, only to be confronted with female genitalia. There are several morals to this story, one being that guinea pigs are exceptional at multiplication. Cornflake gave birth to two beautiful babies – Osler and her brother Cushing. (And yes, you need to separate young males from their mothers fairly early on).

  • Quarantine the new guinea pig or at very least have a vet check to rule out infectious disease, e.g. the cavy might Trixacarus caviae.
    Trixacarus caviae
    The guinea pig mite, Trixacarus caviae.
  • If you have time and both guinea pigs are well, consider scent swapping. This is where you take an item from one enclosure and place it in the other guinea pig’s enclosure, so they can get accustomed to each other’s scent.
  • Introduce them in neutral territory. They are less likely to fight or disagree if both are in a new environment. I use the bathroom because I can close the door and give them space if they hit it off.
  • Provide a salad. Lots of species bond over food and guinea pigs are no exception. Greens and herbs like fennel and mint are popular. Usually I put this in between the guinea pigs in their neutral environment, and let them work their way towards it.
  • Clean the enclosure. Fresh substrate, bedding and food mean fresh smells that both pigs can explore. Provide at least two water sources and scatter food through the enclosure so everyone can access food.
  • Provide one or more hides. The best are open-ended, e.g. tunnels that guinea pigs can run through. This way no one can be cornered.
  • You may need to perform several introductions before all goes smoothly, but it often does. Usually guinea pigs become very vocal, walk around each other, sniff, occasionally “popcorn” and then share a salad.
  • Keep an eye out for any tensions once they’re in the enclosure together.


In the case of Osler and Fitzy, they were enjoying their fennel salad within minutes of meeting and settled in without any problems.