Q: Is it normal for a guinea pig to sneeze after eating hay?
A: A tickle in the nose will cause any guinea pig to sneeze, especially after burrowing down into dusty hay. Even the cleanest hay can have residual dust. But these sneezes should be few and far between.
A guinea pig that sneezes a number of times within an hour may have a respiratory ailment or be developing one. Additional signs include discharge from the nose, crusty eyes, lethargy, failure to eat or drink, or acting all hunched in a cage.
Guinea pigs cannot hunker down and ride out a respiratory ailment; they should get immediate medical treatment by a veterinarian who is knowledgeable about treating guinea pigs. Guinea pigs will hide signs of illness as an instinct to protect the herd. In the wild, showing signs of illness might draw predators and endanger their companions, so guinea pigs instinctively hide illness until they are overcome by it. Many prey species do this as a hard-wired response.