Possible Clues:

• Org. that battled P. T. Barnum
• Pro-Fido org.
• Dogfighting-fighting gp.
• Pro-adoption org.
• Org. for pound watchers?
• Labrador retriever?
• Oldest animal-safety org. in the U.S.
• Certain rescue org.
• Org. concerned with equines
• Humane org. founded in 1866