I remembered discovering either Call of the Wild or Whitefang when I was a boy and really liking it, so on finding this on our shelves I read it to Celyn (12 but too disabled to read). 
 I found myself translating on the hoof as the book was written in 1903 and much of the language is quite Dickensian. Celyn's vocabulary, whilst largely unknown to me, must be derived from books and conversations, and neither of those would have supplied her with many of the words in Call of the Wild. 
 I found myself having to find more comprehensible substitutions for sentences in the style of: "His primeval perspicuity endured the ardor of robust toil." as I read them. I also took time to precis what had happened every few pages. 
 The book wasn't written for children. It was first published in sections in a national newspaper and satisfied the readers' curiosity about life in the Alaskan wilds during the recent (ongoing?) gold rush. Jack London spent a lot of time out in the wilds with the men, sleds, and dogs, researching for the story, so the technical detail is accurate and serves as reportage. 
 It's a pretty grim tale told with as little anthropomorphism as can be achieved without destroying comprehension. Our hero, the dog Buck, is stolen from a loving home to satisfy the need for sled dogs in the gold rush. We meet a whole succession of some 20+ dogs and (view spoiler)[ every single one of them dies a gruesome death (hide spoiler)] . Some of the dogs meet very moving ends. The human cast changes swiftly and many of them fare little better. 
 The story structure is unusual and the whole book very short (somewhere in the 30-40,000 word range). It is, however, (or perhaps because) engaging and 'educational'. I thought it was a good read, though now it's reaching for 4* whereas the boy-Mark would have given 5* without a second thought ... though perhaps he read Whitefang instead... 
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