A dog makes his way back home to his owner after they’re separated in a bombing during the Korean War.

Make it against all ods.

Maybe. "After being separated in a bombing during the Korean War, an injured Chihuahua -- through inhospitable mountains -- makes his way back home to his owner."

But not sure the sentence construction works.

Good stuff Richiev. I had this flash of an apple head chihuahua the person/soldier kept in his shirt before getting separated 😉

After I read this, my first thought was, this logline has all I need, a lead character, an inciting incident, a goal, and you even gave us the setting.

However, after I read Odie's advice I will add one thing.

A long time ago I read a book by Natalie Goldberg called, "Writing Down the Bones" which for me, was probably the most useful, how-to book on writing I have read. Because the book is more about giving you useful tips than teaching, story structure, character building, or what page you should do the inciting incident.

One of the pieces of advice Natalie Goldberg gave was this... Everything has a name. It's not a tree, it's an Oak, a Hemlock, or perhaps a weeping willow. It's not a car, it's a metallic grey honda, a yellow Volkswagon bug, or a 68 Chevy Camero. And when you use the proper name, it puts images into the reader's head.

If the reader has seen a weeping willow, when you use the proper name you won't have to go into a half-page of describing it. It will already be in their head.

So when Odie asked if you have any special characteristics for the dog, I was reminded of this. Is it a German Shepard? A Poodle? or perhaps a Black Lab? Each will put a different image into the reader's head and doesn't really add much to the word count.

Anyway, just a thought inspired by what Odie had written in his comments.

Hope this helped