Not necessarily. Sometimes the concept of 'happily ever after' in manga can be interpreted in unconventional ways, depending on the story's theme and message.
Yes, it usually does. Puppy hair has the ability to regrow after mange, as long as the underlying condition is properly treated and the puppy's health is restored.
First, establish a routine for training. Set short, frequent sessions. Use toys to make it fun. Also, socialize your puppy early to prevent behavioral issues. Consistency is key!
I haven't actually read the 'End of Ever After' novel specifically, but generally, it could be about the conclusion of a long - held state of 'ever after' like the end of a happily - ever - after scenario in a fairy - tale - like world. It might deal with the breakdown of an idyllic situation, perhaps due to some external force, internal conflict, or the passage of time.