And if you prefer that all your hard work not go to the dogs (and the cats), then try crises pregnancy centers, children's homes and hospitals, hospice care, shut-ins, and foster children.
You can also contact the churches around you and see if their ministries have a need for blankets. Or pick a disease (cancer, AIDS, MS, MD, etc.), find an organization that works with these patients, verify the organization's track record, and then contact them to see if they can use your blankets.
If you want to branch out and send your blankets around the world, pick a group to help: orphans in Bangladesh, rescued child soldiers in Africa, AIDS babies, rescued victims of human trafficking, etc., etc. Find an organization that helps these people, verify that organization's track record, and then contact them about your blankets.
The options are limitless! You might also check the following places for charity threads: Ravelry, crochet forums, and quilting forums.