Koko, a Red Cloud Kelpie, passed away in Perth, Australia at the age of seven after succumbing to congestive heart disease.
Producer Nelson Woss, who became Koko's owner after the film shoot, says, "Through the making of Red Dog, Koko became Australia's favourite dog. He certainly changed my life forever. I will miss his companionship, his remarkable outgoing, friendly nature and the many long walks that we enjoyed together in Perth and around the country. His incredible journey has come to an end."
Director Kriv Stenders adds, "Ironically it reflects the theme of the film - it taught us about the cycles of life. The preciousness of friendship and loyalty, and I think personally I feel like I learnt a lot from Koko. I knew he was having a bit of a battle, but he had a reprieve a month ago. For a short seven years, he certainly made a big difference."
Koko was honoured with the Best Dog in a Foreign Film prize at the inaugural Golden Collar Awards in Los Angeles in February (12).
Lucas was named Best Actor for his performance in the Australian family movie, which scooped a total of six prizes including Best Director for Kriv Stenders.
The American actor was unable to collect his prize at the Sydney ceremony due to other filming commitments, but his canine co-star Koko went in his place.
Red Dog producer Nelson Woss joked, "He (Koko) is very happy to be here, although he is a bit grumpy that the film has gained nine nominations and there isn't a single one for him."
British actress Emily Watson was also a big winner - she received the Best Actress trophy for her portrayal of a social worker in Oranges and Sunshine.