In Episode 21 of "The Knowledgeable Pet Owner," the hosts discuss the crucial information groomers need from pet owners to ensure a safe and comfortable grooming experience. They emphasize the importance of informing groomers about any health issues, medications, and behavioral problems that a pet may have, as these factors significantly affect how grooming should be conducted. The hosts also point out that different pets may require different grooming environments, and knowing a pet's reactions to certain stimuli helps groomers better anticipate and manage potential issues. Additionally, skin conditions and allergies need to be communicated so that appropriate products and techniques are used. Ultimately, transparent communication from pet owners is essential for groomers to provide the best care and ensure the safety of both pets and grooming professionals.