Dog Dander is a common particle in many indoor environments. It can be easily identified by its elongated
shape and birefringence, which is higher than human or cat dander. In offices and classrooms it is one of
the "track-in" particles that come in on the clothing of a dog owner. It is occationally quite high in a
sample, which generally indicates a service dog is present. The most common look-alike is fine sawdust.