Chaplain of Pets is an interfaith ministry to pets and their people. It’s based in Stone Mountain, Ga.

James Serpell is a professor of humane ethics and animal welfare at the University of Pennsylvania’s school of veterinary medicine. He directs the Center for the Interaction of Animals and Society.

Andrew Isenberg is a history professor at Temple University in Philadelphia. He is an expert on the history of American environmentalism, especially in the American West. He contributed a chapter on the moral ecology of wildlife to the book Representing Animals.

Katherine C. Grier is professor of material culture studies in the University of Delaware’s Winterthur Program in Early American Culture. She has studied the relationships between humans and animals, and her books include Pets in America: A History (2006).

David Dion DeGrazia is a philosophy professor at George Washington University in Washington, D.C. He has written about the ethics of animal research and is the author of Animal Rights: A Very Short Introduction.

The Rev. Victoria Weinstein is pastor of First Parish Church of Norwell, Mass., a Unitarian Universalist congregation. In May 2006, she delivered a sermon on the spiritual value of animals.

The Rev. Nancy Taylor is senior pastor of the Old South Church, a United Church of Christ congregation in Boston. In May 2006, she preached a sermon on the blessings given and received by animals.

Lori Gruen is an associate professor of philosophy and of women’s studies at Wesleyan University in Middletown, Conn. Among her areas of interest is injustice to animals. As a guest on a May 11, 2004, podcast of Philosophy Talk, she discussed the morality of eating animals.

Christine Gutleben is director of the animals and religion program for the Humane Society of the United States. She has an undergraduate degree in religious studies and a master’s degree from a theology school, where she studied theology and ethical food choices.