Several types of lilies are toxic to dogs. Owners must avoid exposing their dogs to the peace lily, calla lily, amaryllis, lily of the valley, autumn crocus and palm lily. Ingestion of these plants can cause gastrointestinal distress, depression, tremors and a loss of appetite.
The Continental Kennel Club offers suggestions to prevent dogs from eating plants. Owners must keep all indoor plants out of the reach of their dogs. A dog that goes after vegetation to increase his fiber intake requires more roughage, such as bran flakes. When purchasing house or garden plants, dog owners must be aware of those that are dangerous to their pets and arrange them safely.