AB 1428, the California bill to ban commercial pet cloning and genetic modification, was supported by a coalition known as Californians Against Pet Cloning (CAPC), whose members include:

The American Anti-Vivisection Society

United Animal Nations

International Center for Technology Assessment

Their website, NoPetCloning.org, is an excellent resource. Other organizations on record as opposing pet cloning include:

Center for Genetics and Society

Dane County (Wisconsin) Humane Society

American Humane Association

Church of Scotland's Society, Religion, and Technology Project

Friends of the Earth

Humane Society of the United States

National Humane Education Society

Roslin Institute

Even the Roslin Institute, which cloned the sheep known as Dolly, has opposed pet cloning. Dolly had to be euthanized in early middle age, suffering from lung cancer and arthritis. According to the scientific journal Nature, such premature death "is typical of cloned animals."

Genetically modified pets have been perceived until recently as a more remote concern, and have not yet attracted the same level of organized public opposition. Fish, rabbits, and other possible pet species have been cloned. The debate around AB 1428 will provide an opportunity to bring together all those concerned about these activities.

http://www.NoPetCloning.org/

Pet Cloning: Separating Fact from Fluff, The American Anti-Vivisection Society (February 16, 2005)
http://www.nopetcloning.org/img/original/report21605.pdf

Wayne Pacelle, "Is Animal Cloning Ethical?" San Francisco Chronicle, (January 21, 2005)
http://sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2005/01/21/EDGN0AT3861.DTL

Griff Witte, "New Biotech Pets Make Some Uneasy," Washington Post, (March 13, 2004)
http://www.thecampaign.org/News/march04s.php

Friends of the Earth and Humane Society Joint Statement on Pet Cloning
http://www.foe.org/camps/comm/cloning/hsusfoeletter1.html

Humane Society of the United States Statement on Pet Cloning
http://www.hsus.org/pets/issues_affecting_our_pets/hsus
_statement_on_the_cloning_of_pets.html

Roslin Institute Statement on Pet Cloning
http://www.roslin.ac.uk/news/articles/155.html