What are common causes of mastitis in dogs?

The correct answer relates to the conditions that can lead to mastitis in dogs, particularly in nursing females. Mastitis is often caused by physical factors that involve the nursing process, including situations where there is an excessive amount of milk that cannot be adequately removed due to insufficient suckling from the puppies. When the milk accumulates in the mammary glands and is not expelled, it can lead to inflammation and infection, ultimately resulting in mastitis.

Inadequate dietary intake and dehydration can impact a dog's overall health but are not direct causes of mastitis. Similarly, while excessive exercise and anxiety can affect an animal's well-being, they do not directly correlate with the development of mastitis. Lastly, a low energy diet and infections can affect health but are not as directly relevant to the mechanical and physiological causes associated with nursing and milk production.