| Abbreviation | Definition |
|---|---|
| MISCELLANEOUS | Miscellaneous |
| MIWA | Merritt Island Wildlife Association |
| MKKA | Minnesota Killie Keepers Association |
| MLAR | Main Line Animal Rescue |
| MLAS | Master of Laboratory Animal Science |
| MLG | Magical Lion Grownup |
| MMAH | Mississippi Mills Animal Hospital |
| MMAH | Mitchell Mill Animal Hospital |
| MMCR | Mid Michigan Cat Rescue |
| MMHAA | Mangalarga Marchador Horse Association of America (humane breed association) |
| MMMTC | Midnyte Mountain Miniature Training Center (miniature-horse training facility; Springfield, MO) |
| MNKY | Monkey |
| MOAS | Madison Oglethorpe Animal Shelter |
| MP | Mother Pig |
| MPFA | Michigan Pet Fund Alliance |
| MRAH | Monument Road Animal Hospital |
| MSBOON | My Sad Baboon Oliver Obliged Nolan |
| MUTO | Massive Unidentified Terrestrial Organism |
| MYLF | Mountain Yellow Legged Frog |
| NAA | Nimrokko Animal Army |