| Abbreviation | Definition |
|---|---|
| A | Animals |
| A | Ant |
| A | Anteater |
| AAA | Animal Acupuncture Academy |
| AAA | Animal Agriculture Alliance |
| AAAA | Association for Applied Animal Andrology |
| AAALAC | Association for the Assessment and Accreditation of Laboratory Animal Care International |
| AAAV | Avian Adeno Associated Virus |
| AABC | Animals Are Brookhavens Concern |
| AABP | American Association of Bovine Practitioners |
| AAC | Animal Appreciation Club |
| AACV | Australian Association of Cattle Veterinarians |
| AAEM | American Association of Electrodiagnostic Medicine |
| AAEP | American Association of Equine Practitioners |
| AAEVT | American Association of Equine Veterinary Technicians |
| AAFCO | Association of American Feed Control Officials |
| AAFHV | American Association of Food Hygiene Veterinarians |
| AAFP | American Association of Feline Practitioners |
| AAHA | American Animal Hospital Association |
| AAHC | Australian Animal Health Council |