Strelka and Belka from Space Dogs, a Russian animated movie.
Watched it some days ago because of a friend's fanart and the movie was.. not the best, neither completely awful but still watchable?
Also the animation was pretty cheap. HOWEVER it made me read more about Soviet space dogs since the movie is based on/dedicated to the IRL Belka and Strelka, the first dogs who actually survived the orbital flights.
The most known space dog is Laika. Poor thing died shortly after the start because of overheating. She was even meant to die, but the scientists didn't expect it to die her that fast.
You could say it's animal cruelty made into animated movie for kids woops

Characters belong to the Centre of National Film Studio
Artwork © Kikonine