Can I repair a solid wood door frame that was chewed by a dog?

This is not very common but should be able to be dealt with.

Looking at the photo it is a little larger in size but not very deep. My dog chewed on things when he was a kid too, and it got better as he got older.

Of course to say how to fix it. Wooden things are afraid of water, so before using other materials should be used to use primer or 108 adhesive on the board to close, to prevent peeling. Then use strong plaster priming, not putty. Third, use high-strength anti-rip mesh with glue for thorough closure. Finally, sand for flatness and then paint with high elastic paint.

This approach is based on a combination of other people's opinions and mine, which is probably right.

So you should find a professional worker (such as the manufacturer of solid wood doors you buy after-sales staff) to show you exactly how to do it, let him say clearly and then start work, I believe it can be done well.