In the U.S., the path from public or private shelters to laboratories is treat too often by dogs and cats. In a few states, so-called "pound seizure" laws require shelters to turn over unclaimed or unwanted dogs and cats to researchers. In other states, shelters may voluntarily sell dogs and cats to "bunchers" who travel around a state or states, bunching animals together to resell to research facilities. Even in the handful of states that prohibit release of animals for research purposes, unscrupulous profit seekers can find animals and sell them for research across state lines.
Many scientists claim these "random source" animals from shelters are stray dogs, not pets. But in Ohio, the required holding period for a stray animal is only three days. We'll never know how many pets were sacrificed in research labs while their frantic owners were still vainly searching for them.
The Humane Society of the United States, "Is Your Pet Safe From Laboratory Experimentation?" (1982). CUP. 23.