I want to know the answer to the following question:
Why were sled-dogs used to deliver medicine to Nome in 1925?
All the background I'm provided with is that "The "Serum Run" is another sled dog race that more accurately follows the route of the famous 1925 relay, leaving from the community of Nenana (southwest of Fairbanks) to Nome.". Is that enough to answer the question?
Answer: no