There are a few different questions I get asked regarding other pets in a household with guinea pigs, especially dogs and cats. By nature, dogs and cats are predators and guinea pigs are prey. Curiously, even though guinea pigs are prey, the tamer ones of their kind will not usually show fear when faced with a dog or cat and are seemingly unaware of the danger that is literally facing them. I noticed that most piggies will come right up to the front of the cage to say "hi" when a dog is brought in to the pig room. Sadly, not all dogs and cats (but especially dogs), share the guinea pig’s innocent and friendly nature. So, can guinea pigs live with dogs and cats?
A common reason for surrendering a guinea pig (I see this a lot) is there's a dog in the household with an unhealthy interest in the guinea pigs. Dogs with a high prey drive will not usually give up until they get what he wants. It's an urge and an instinct that is stronger than anything. In this case, it's likely best to protect the guinea pigs by finding them a safer home or find a new home for the dog where there are no guinea pigs or other small pets present.
Living with a dog with a high prey drive and constantly having to worry about your guinea pigs is extremely stressful. Not only that, but these are situations that are likely to end in tragedy.
The opposite to this is a dog who loves the guinea pigs, sleeps with them, licks them, protects them and is extremely gentle with them. And then there is the dog that is in the middle of the two, a dog with an "I can take it or leave it kind of attitude."
I always urge people to be extremely cautious. A seemingly gentle and sweet dog may just be waiting for the opportunity to pounce on the guinea pigs. And an overly excited pup may just be desperate to meet the guinea pigs to become their new best friend. You just don’t know. So the best thing is to test the dog.
This is a test you can do that is safe for the guinea pigs. Put the guinea pigs in a sturdy cage with metal bars and a top and bottom. Keeping the dog on a leash slowly walk toward the cage with the piggies. You can tell a lot by the dogs reaction. You may be able to tell immediately that the dog will be a danger to the little guys if he lunges at the cage. A dog that (once he becomes aware of the piggies in the cage) will stand very still and stare at the pigs (without wagging his tail) is often scheming to get to them. Whereas the excited, loudly barking, tail wagging pup may be totally harmless. This test will tell you a lot but is by no means fool proof. I think that the better way to find out is to get the help of a dog professional who can interpret the behavior toward the guinea pigs.
Cats can pose a threat as well and the same caution must be exercised. A similar test can be done with our feline friends as well.