Dolly faces various challenges throughout the story due to her age and weakening condition.
1. Exhaustion and Mistreatment: The harsh wilderness and demanding workload take a toll on Dolly. She struggles to keep up with the pace of the younger dogs and often lags behind. François and Perrault, despite their affection for her, sometimes resort to harsh measures to keep her moving.
2. Falling Behind: As the journey progresses, Dolly's exhaustion becomes more pronounced. She frequently falls behind the team, causing delays and frustration for the mushers.
3. Abandoned in the Snowstorm: During a particularly treacherous blizzard, Dolly collapses and is unable to continue. Knowing that they cannot afford to wait, Francois and Perrault make the difficult decision to leave her behind. They place her in a sheltered spot, hoping she might survive the storm, but they have little choice but to move on.
4. Rescue by Buck: Later on, Buck, the protagonist dog of the story, who has become the leader of the team, senses that Dolly is still alive. He breaks away from the team during a brief rest stop and sets out to find her. He successfully locates Dolly and brings her back to the camp.
5. Reunion and Recovery: The team reunites with Dolly, and they work together to care for her. With time and care, Dolly recovers her health and strength, although her age still limits her abilities.
Despite her challenges, Dolly's loyalty and indomitable spirit endear her to the hearts of readers. She embodies the theme of survival amidst adversity prevalent in the harsh wilderness.