One reason is that if they didn't have the required amount of dogs, they would be disqualified. I'm not sure about the other reason.
There are a number of behaviors that could disqualify a musher from the Iditarod race. Two of the most common are animal neglect or cruelty or sabotage of other teams or mushers. Dogs are also checked for illegal drugs.
what route will mushers take
Mushers cook food in a bonfire while they race
because
63 mushers began the race, however 9 have scratched.
CORN
The largest number of mushers to finish a race is 77.
it was to commemorate the serum race, mushers + dogs
BY AND I OOP SKSKSKSKSKSKSKSKSKSKSKSKSKSK
They might be disqualified
The US 4x100 team was disqualified from the race because one of the runners stepped out of their lane during the race, which is against the rules of track and field.
If Swimmer B was second in the race and D was 1st and Disqualified Swimmer B would then win the race.