Whiskey's family did bloodwork which looked good and a biopsy of the mass that proved he had an 8x10cm spindle cell sarcoma mass on the right side of his anus. (frostedfacesfoundation.org)
Skunks have two glands, on either side of the anus, that produce a mixture of sulfur - containing chemicals (methyl and butyl thiols) that has a highly offensive smell. (sciencedaily.com)
All cats have a pea - sized anal sac that sits on both sides of their anus. (petsmagazine.com.sg)