Unknown Breed

An unknown breed laboratory mouse is a Mus musculus animal whose laboratory mouse identity is known, but whose strain, stock, or breeding background has not been confirmed. It may look like an albino, black, or mixed-background mouse, yet coat color alone is not enough to identify a laboratory strain. The label should be treated as an honest statement that the animal's background is missing.

Unknown-breed mice can be cared for using standard mouse housing, enrichment, feeding, and handling practices, but they should not be represented as BALB/c, C57BL/6, or any other named strain without evidence. For rescues, teaching programs, or colony managers, the safest approach is to keep them separate from defined lines and document source, date received, sex, health status, and any breeding that occurs.

Colors: Albino, Black