Courage saw memories of his parents in the cartoon Courage The Cowardly Dog Season 4 Episode 13 with the title “Remembrance of Courage”.
In this episode Courage is being fixed a meal of chicken dumplings which are his favorite (stated by Muriel). However upon drinking some milk during his feast, he sees pictures of missing dogs on the box. This triggers memories of his mother and father, who were tricked and nabbed by an evil veterinarian who was really a mad scientist carrying out experiments on breeding dogs in space.
Courage’s Mother and Father fell victim to the evil Vet and were launched to the moon in a rocket. Courage tried to rescue his parent during that ordeal but was unsuccessful and had to escape instead. He was then found by Muriel who took him in and raised him.
This memory sends courage into shock and so he is taken to the same vet by Muriel and Eustace. The Vet declares that he would like to have a moment alone with Courage, and Muriel consented; Courage gets freighted and runs off thorough the hospital, pursued by the Scientist. Eventually he is captured and thrown into a rocket.
Muriel and Eustace arrive at the lab but are thrown into the rocket as well. Courage escapes, frees Eustace and Muriel then managed to push the Scientist inside the rocket before launch. At the last scene the evil vet arrives in space only to meet with the dogs he blasted off in space, which then attacked him.