Pets eat lawn grass and other plants because they have a nutritional deficit.

Dogs and cats are carnivores. This means that they evolved to eat a primarily meat-based diet. It is likely, however, that their wild ancestors occasionally supplemented their diets with vegetation. Dietary flexibility can be an important adaptation in times when usual food sources are scarce, for example, in times of drought. There is no evidence that eating plants is associated with any dietary imbalance or search for fiber.

Pets are often initially attracted to household plants because of their natural instinct to evaluate new objects. This is typical of young kittens and puppies, for example, that base their initial exploration of the world on oral investigation. They may then develop a preference because of taste or consistency for a specific plant that could well become part of their basic diet. If your pet’s interest in your plants is simply a playful nuisance, place these plants out of reach or in a room that is off-limits. In some cases, it might be best to tailor your choice in houseplants to ones that do not attract your pet.

This behavior is usually not a health risk but should be discouraged if the plant is toxic to pets. Lawn grass is not poisonous. However, if it has been treated with insecticides, it could become a menace to your pet. Some household plants and some shrubbery and trees common in home landscaping contain substances that are toxic to pets. Your veterinarian should be able to inform you if your plants pose a problem.