How's this for an idea. Victor owned the dog we know as Redbeard, the red Irish Setter of Sherlock's memory. But it's name wasn't Redbeard, that was the name of the pirate Victor liked to pretend to be in their games. The dog would have been named something boring and forgettable. Wherever Victor went, the dog went too (when the kids played outdoors). They were inseparable. Sherlock was envious and wished he had a dog like that, but he wasn't allowed because his dad was allergic to dogs. Maybe something happened to the dog (maybe Eurus did something nasty to it, but nobody knew it was her) and it had to be put down. Then came the tragedy of Victor disappearing... and somehow in Sherlock's mind the two were merged into Redbeard the dog. That's why we see and hear a dog in both Sherlock's and Mycroft's memories/flashbacks. That's why there was a dog bowl (Eurus got hold of it at some point, perhaps as a trophy). Imagine how confusing it all would have been for little Sherlock. Maybe his parents and brother tried to explain, but it was too traumatic and in the end they just let him believe what he thought he remembered.

Anyway, that's one possible explanation. I don't think Moffat and Gatiss are the sorts of writer's who worry about explaining all the details, and getting into discussions in the aftermath of TFP about the police searching for Victor etc. would have seemed unnecessary to them. Perhaps they didn't have this particular scenario in mind, but it works for me
 

Goteborg: Finnish-American Snapper Films Unveils ‘Sherlock North’

GOTEBORG — Finland-U.S.-based Snapper Films has unveiled a new TV series “Sherlock North,” which adds an intriguing twist to one of the most valuable of European entertainment properties.

Not many people know it, but in 1903 Sir Arthur Conan Doyle wrote a short story, “The Adventure of the Empty House,” where after faking his his own death at the Reichenbach Falls, Sherlock Holmes travels to Scandinavia, on the run from nemesis Professor Moriarty.

Under a false identity – an explorer named Sigerson – Holmes settles in dark and cold Lapland, in northern Finland, sparking a culture clash between the upper-class, fast-talking and eccentric Brit and the down-to-earth Nordic characters.

Finnish writer-director-producer Juha Wuolijoki will run the upcoming 10-hour television series “Sherlock North,” which he introduced yesterday as a work-in-progress at the TV Drama Vision section of  the Nordic Film Market in Göteborg’s 40th Film Festival. He aims to shoot the series in the winter of 2018, at the latest 2019. Finnish broadcaster YLE is on board for series development.

A film graduate from Helsinki’s University of Art and Design, Wuolijoki was interested from an early time in his career in working with foreign partners, and also actors: “There are great artists in Finland, but when you are outside your comfort zone, you have to push yourself,” Wuolijoki said.

One of his first films was a half-hour short, “Paulie,” shot in New York with, among others, the later Emmy-winner Michael Badelucco; he then directed three features: “Christmas Story” (2007), a Finnish family fantasy which tells the story of how Santa Claus became Santa; a Finnish period bio pic, “Hella W” (2011); and “Zarra’s Law” (2014), an English-language crime drama set in New York.”

In 1998 Wuolijoki set up production company Snapper Films in Helsinki. In 2007, it produced �

…