‘Puppy’ is a term derived from the Latin ‘catellus’ (small dog) used to refer to an unweaned young male or female canine during the first months of its life. Depending on the breed and size category, this period lasts between ten and eighteen months, the age at which it definitively becomes an adult. The life expectancy of sled dogs is estimated at 12-15 years, it is not reduced due to their more intense activity nor their harsher living conditions.