Guinea pigs are herbivorous animals that require a diet rich in fiber, vitamin C, and other essential nutrients to maintain optimal health. Their primary diet should consist of high-quality hay, fresh vegetables, and a limited amount of fruits. While mushrooms are a common food item in human diets, their suitability for guinea pigs is a topic of concern among pet owners. According to information from Chestnut Mushrooms, certain types of mushrooms, such as white button, cremini, and portobello, are not toxic to guinea pigs and can be consumed in small quantities. However, it's important to note that mushrooms offer limited nutritional value for guinea pigs, as they lack sufficient fiber, vitamin C, and calcium, which are crucial for the animal's health. Feeding mushrooms to guinea pigs can lead to nutritional deficiencies if they replace more nutrient-rich foods in the diet. Moreover, wild mushrooms pose a significant risk, as they can be toxic and potentially fatal to guinea pigs. Even store-bought mushrooms should be given raw, thoroughly washed, and in moderation to prevent digestive issues. Cooking mushrooms is not recommended, as guinea pigs cannot properly digest cooked foods, and it may lead to gastrointestinal distress. Given these considerations, it's advisable to focus on providing guinea pigs with a balanced diet that includes hay, fresh vegetables like bell peppers and leafy greens, and occasional fruits such as apples and berries. This approach ensures that guinea pigs receive the necessary nutrients without the risks associated with feeding them mushrooms. For more information on appropriate dietary choices for guinea pigs, consulting with a veterinarian or referring to reputable sources on guinea pig nutrition is recommended.​