Hackpacker included a link to a dog-sledding site and I checked out the photos, but the text is presumably in Russian. (I once spent six months studying Russian but I'm embarrassed to admit I didn't even learn enough to be sure this text is Russian.)
Hackpacker also includes a link to
the story of Nicholas Vanier, a modern day adventurer who took a team of dogs from Baikal all the way to Moscow and almost froze to death several times in Siberia.
But it's in French. (Okay, time to admit I did SIX years of French at high school and can't remember much - but that's over forty years ago, so I reckon I have an excuse this time.) However, I did find a text in English that seems to be on the same topic. Here's a site by the energy company that supported Vanier's dog expedition.
And here's a site that is highly critical of Vanier's treatment of his dogs. Which got me thinking about other dog sled events and I came across the Yukon Quest page describing the level of veterinary care dogs receive in this event.
It does seem that one man travelling eight thousand kilometres would have trouble providing this level of care.