Here are some things to keep in mind:
* Supervise interactions: Never leave your Wheaten terrier unsupervised with a guinea pig, even if they seem to be getting along.
* Train your dog: Teach your Wheaten terrier basic obedience commands like "leave it" and "drop it". This will help you control their behavior around the guinea pig.
* Separate living spaces: If you can't supervise your dog and guinea pig, consider keeping them in separate areas of the house. This will help to prevent any accidental encounters.
* Guinea pig safety: Ensure your guinea pig's enclosure is secure and your Wheaten terrier cannot access it.
It's important to remember that even if your Wheaten terrier has never shown aggression towards guinea pigs, it's important to always be cautious and take precautions to ensure their safety.