Because price is not nutrition: the cheapest mix can be mostly fillers for some species, while a slightly pricier hay or pellet prevents expensive health problems. Compare like for like, check ingredients, and read species-specific feeding guidance before switching.

Gradually, over 7-14 days, mixing increasing amounts of the new food with the old. Rabbits and guinea pigs are especially sensitive to sudden diet changes, which can stop their digestion — a fast switch can cause a vet visit.

Buying bigger bags, comparing price per kilogram, cutting sugary treats and avoiding fancy packaging all save real money without changing the core diet. Start there before downgrading the food itself.