Meghan Markle has written a foreword for the Annual Review of Mayhew, the U.K. animal welfare charity of which she’s a royal patron.

The Duchess of Sussex began by referencing her rescue dog Guy, which moved with her from Canada to London and was by her side on the morning of her wedding to Prince Harry last May. The Duke and Duchess of Sussex also became the new owners of a Labrador puppy last August, just a few months into their life as newlyweds.

“As a proud rescue dog owner, I know from personal experience the joy that adopting an animal into your home can bring,” the Duchess of Sussex wrote. “The role that we, as people, play in rehoming and rescuing these animals is vital, but the role of organisations such as Mayhew is unparalleled."

PHOTO: Prince Harry and his wife Meghan, Duchess of Sussex, pose for a photo with their newborn baby son in St George's Hall at Windsor Castle in Windsor, England, May 8, 2019.
Dominic Lipinski/Pool/AFP/Getty Images
Prince Harry and his wife Meghan, Duchess of Sussex, pose for a photo with their newborn baby son in St George's Hall at Windsor Castle in Windsor, England, May 8, 2019.

Mayhew offers veterinary care and support for dogs and cats around the world. The Duchess of Sussex, who is officially on maternity leave after giving birth to her son, Archie, on May 6, wrote the foreword before the baby arrived, a palace source told ABC News.

PHOTO: Britain's Prince Harry and Meghan, Duchess of Sussex, hold their newborn baby son in St George's Hall at Windsor Castle, in Windsor, England, May 8, 2019.
Dominic Lipinski/Pool via Reuters
Britain's Prince Harry and Meghan, Duchess of Sussex, hold their newborn baby son in St George's Hall at Windsor Castle, in Windsor, England, May 8, 2019.

In the foreword, she went on to praise the charity for the work it does in improving communities.

The choice to adopt a pet is a big decision that comes with much responsibility but infinite return on the investment. It will undoubtedly change your life.

"What initially struck me about Mayhew specifically is their community approach not simply to rehoming animals, but in the preventive care that inhibits these cats and dogs from ending up in shelters in the first place," she said. "From Mayhew's global education programmes to their community work on a micro level with the elderly, homeless and vulnerable communities, they actively seek solutions that allow people to stay with their animals and have the support they need to do so."

From her experience as a rescue dog owner, Meghan said adopting a pet "will undoubtedly change your life."

"The choice to adopt a pet is a big decision that comes with much responsibility but infinite return on the investment," she said. "As Patron of Mayhew, I encourage you to get involved in whatever way you can - either through pet adoption, volunteering, donation, or spreading the word. We are all interconnected and through these animals we find an even great link to community and the part we can play."

PHOTO: Meghan, the Duchess of Sussex meets "Foxy" during her visit to the Mayhew, an animal welfare charity, Jan. 16, 2019, in London.
Eddie Mulholland/Getty Images
Meghan, the Duchess of Sussex meets "Foxy" during her visit to the Mayhew, an animal welfare charity, Jan. 16, 2019, in London.

In January 2019, Meghan made a public visit to Mayhew and held some of the charity’s rescue dogs as she visited with staff and volunteers.

In addition to Mayhew, the Duchess of Sussex is also the patron of Smart Works, a charity that helps women get back on their feet, the National Theatre and the Association of Commonwealth Universities.