anal sac

noun

: one of the usually paired small pouches of glandular tissue that are located on either side of the anus between the internal and external anal sphincters of various animals (such as dogs, cats, skunks, and foxes) and that discharge often strong-smelling secretions into the anus : anal gland

I don't think anyone truly knows why dogs have anal sacs, but the most prominent theory is that they are used as a marking scent.

—Jim Berg, News Journal (Wilmington, Delaware), 24 June 2008

Word History

First Known Use

1826, in the meaning defined above

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