Culbro, a family-controlled private equity firm based in New York City, has made a minority investment in TDBBS, a manufacturer and marketer of dog treats and chews. Based in Richmond, VA, TDBBS specializes in bully sticks, elk antlers and other high-protein dog chews that are easily digested. The company also offers complementary, all-natural dog treats and chews to customers through its proprietary e-commerce sites and other retail channels. Formed in 2005, Culbro primarily focuses on making equity investments of $10 million to $20 million in middle-market companies across a number of sectors, including branded consumer products, healthcare services, education products and services and other outsourced services, including information technology.