The film was altered from its original Japanese release when it was brought to English speaking countries. A large amount of footage of animals in dangerous, perilous situations (including scenes where it appears the animals are severely harmed and intentionally put into perilous situations) were removed to avoid controversy.
This film has been controversial since its release due to allegations of animal abuse, including claims that a number of kittens were killed during filming. Animal advocacy groups were not allowed to supervise during production, so those reports can't be confirmed. However, many have noted that the dangerous conditions the animals were placed in (including footage of a cat falling off of a cliff) were likely due to the filmmakers intentionally putting the animals into those situations.
Took four years to complete.
The original Japanese title, 'Koneko Monogatari' literally means 'A Kitten's Story'.
In the American version of the film, Otis was named after singer Otis Redding. Screenwriter Mark Saltzman was inspired to give him that name after seeing the pug literally "sittin' on the dock of the bay" - a well-known song by Otis Redding.