A dog’s diet should always be tailored to the needs of each individual animal. Most Chihuahuas can do well on a moderate amount of grain; it is not necessary for them to eat grain-free.
The most important factor in nutrition is quality and transparency with ingredients, which means reading your food labels carefully and understanding what you’re personally feeding your pet!
The microbiome of dogs is different from that of humans, but we do know that all mammals experience health benefits from consuming grains (and also vegetables and fruits). Importantly, corn and wheat feed mycotoxins– toxic substances produced by a fungus– at lower levels than other foods for both dogs and people…