I want to offer my pet multiple foods, can this do any harm?
In principle is there no need for animals to switch between foods and protein sources (= flavours). Some animals can get bored with their food. In these, uncommon, cases it is needed to switch. Diets for dogs and cats are complete. Cats and dogs use less senses to judge their food, contrary to humans. Humans judge food, next to scent and taste, also on colour and texture. For dogs, and especially for cats, mainly the scent is of importance and in lesser degree the texture. That is why colourful food is not important.
Changing of foods can upset your pet's intestines, which causes stomach aches.
Especially for animals with food hypersensitivity it is not recommended to switch because of the hypersensitivity reactions caused by ingredients of the food and the risk of developing an allergy, again. That is why it is not recommended to switch foods. When you switch food, keep in mind that the animal needs to readjust to the new food. This adjusting period is around 6 weeks. Switch gradually. For advice, see ‘How can I best switch to a different food?’