About the spelling thing, I don't think that he/she is from an English speaking country so I guess that he/she will publish it in his/her language, so English doesn't matter much
However, what makes me concerned here is WHY WOULD YOU REVEAL YOUR PLOT TO STRANGERS ??? Anyone who read this thread can very well copy your idea and makes it their own. They may even write it better than you and make money with it. THAT IS THE MOST DANGEROUS THING FOR A WRITER !!!
About your question, what I understand is that you need the title for the case/novel with the dog ? Well, since I haven't actually read it yet so I'm also not sure what is best to name (but again DON'T POST IT!), but maybe I can give you some advice...
1. Don't name anything that would spoil your tricks to the readers. That is the most important. Therefore title with "digest" is a no-go. You can hint the readers by making them focus on the dog, but be careful when doing that.
2. For mystery novels, it's better to name it something that would draw the readers' attention and make them want to explore the plot. I personally recommend using mysterious or abstract titles, instead of direct ones ("Murder at some place...", "Murder with something...", "something murder case") that can easily get boring, and it shouldn't be too far from the plot. Of course unless those some place or something can attract readers (e.g haunted mansion) but in this case they seem not.
Lastly, like everyone else has said, I wouldn't rush with the publishing if I were you. However, I hope that you know what you're doing and wish you for your success in your career !