Dr. Marty Becker is the resident veterinarian on "Good Morning America" and the author of two new books, "Why Do Dogs Drink Out Of Toilets?" and "Do Cats Always Land On Their Feet?" Write to him in ...

Before animal research facilities began using individually ventilated cage (IVC) systems for mice, cages were often changed one or more times per week. When using IVC systems, however, it is standard ...