A nice article on Ivan Pavlov in The New Yorker notes that Pavlov funded his lab by selling dog drool to folks looking for a "treatment" for upset stomach:
For more than thirty years, Pavlov’s physiology factory turned out papers, new research techniques, and, of course, gastric juice—a lot of it. On a good day, a hungry dog could produce a thousand cubic centimetres, more than a quart. Although this was a sideline for Pavlov, the gastric fluids of a dog became a popular treatment for dyspepsia, and not just in Russia. A “gastric juice factory” was set up for the purpose. “An assistant was hired and paid thirty rubles a month to oversee the facility,” Todes writes. “Five large young dogs, weighing sixty to seventy pounds and selected for their voracious appetites, stood on a long table harnessed to the wooden crossbeam directly above their heads. Each was equipped with an esophagotomy and fistula from which a tube led to the collection vessel. Each ‘factory dog’ faced a short wooden stand tilted to display a large bowl of minced meat.” By 1904, the venture was selling more than three thousand flagons of gastric juice annually, Todes writes, and the profits helped increase the lab budget by about seventy per cent.