Not a chest infection, Pip. I believe what Rachael meant was that her piggies exhibit similar symptoms (sneezing and wheezing) when the cage is cleaned out/new bedding put in. In other words, the pigs suffer allergies.
Hayfever and sensitivities to bedding and dust is quite common in guinea pigs. The difficulty is in identifying a respiratory infection (URI) from an allergy, because obviously you cannot risk leaving the pig if there is a chance the pig has a respiratory infection. One key sign that it is an allergy is that medication does not make any difference to the pigs symptoms. Another sign is that with URIs, the symptoms tend to get worse rapidly, while hayfever/allergy symptoms can exist for a long time while sometimes being more severe, but then easing off at other times.
A vet check is important to rule out an infection, but it is also important to consider:
- what bedding you use;
- the quality of the hay;
- how often the cage is cleaned out, and how often the hay is topped up;
- the pollen count;
- the weather/temperature/humidity.
Often just monitoring when the symptoms occur can lead you to the cause of the sneezing!