When my children were growing up, we always had a dog for the family, and one of the best ones we ever had was a coal black Great Dane that grew to be a huge dog, and he was very protective of the family, but also had the carefree nature of the Great Dane.
We had his ears cropped, so he had that awesome traditional look , and we named him Mr. Spock, since he had the pointed ears.
We had horses, and the whole family went riding almost every day, and of course, Spock came along with us, so he developed a very muscular and athletic body from all the running along with the horses.
The name really seemed to fit with his dignified personality.