Maria Cohut's purpose in the article "Dogs: Our Best Friends in Sickness and in Health" is to explore the physical and mental health benefits of dog ownership. The article discusses the various ways in which dogs can improve human health, including reducing stress, increasing physical activity, and providing emotional support. Cohut draws on research studies and expert opinions to support her claims, and also provides personal anecdotes and examples to illustrate the positive impact that dogs can have on human health. Ultimately, the purpose of the article is to highlight the many benefits of dog ownership and to encourage readers to consider getting a dog for their own health and well-being.