| Monensin | Organic compounds | Lipids and lipid-like molecules | Fatty Acyls | Fatty acids and conjugates | Details |
| Moxidectin | Organic compounds | Phenylpropanoids and polyketides | Macrolides and analogues | Milbemycins | Details |
| Narasin | Organic compounds | Lipids and lipid-like molecules | Prenol lipids | Terpene glycosides | Details |
| Nequinate | Organic compounds | Organoheterocyclic compounds | Quinolines and derivatives | Quinolones and derivatives | Details |
| Nicarbazin | Organic compounds | Benzenoids | Benzene and substituted derivatives | N-phenylureas | Details |
| Nifurpirinol | Organic compounds | Organoheterocyclic compounds | Furans | Nitrofurans | Details |
| Nitarsone | Organic compounds | Benzenoids | Benzene and substituted derivatives | Nitrobenzenes | Details |
| Nitenpyram | Organic compounds | Organoheterocyclic compounds | Pyridines and derivatives | Halopyridines | Details |
| Norgestomet | Organic compounds | Lipids and lipid-like molecules | Steroids and steroid derivatives | Pregnane steroids | Details |
| Oclacitinib | Organic compounds | Organoheterocyclic compounds | Pyrrolopyrimidines | Pyrrolo[2,3-d]pyrimidines | Details |
| Oleandomycin | Organic compounds | Organic oxygen compounds | Organooxygen compounds | Carbohydrates and carbohydrate conjugates | Details |
| Orbifloxacin | Organic compounds | Organoheterocyclic compounds | Quinolines and derivatives | Quinoline carboxylic acids | Details |
| Orgotein | Organic Compounds | Organic Acids | Carboxylic Acids and Derivatives | Amino Acids, Peptides, and Analogues | Details |
| Oxfendazole | Organic compounds | Organoheterocyclic compounds | Benzimidazoles | Not Available | Details |
| Phenothiazine | Organic compounds | Organoheterocyclic compounds | Benzothiazines | Phenothiazines | Details |
| Phosmet | Organic compounds | Organoheterocyclic compounds | Isoindoles and derivatives | Isoindolines | Details |
| Phthalofyne | Organic compounds | Benzenoids | Benzene and substituted derivatives | Benzoic acids and derivatives | Details |
| Pimobendan | Organic compounds | Organoheterocyclic compounds | Benzimidazoles | Phenylbenzimidazoles | Details |
| Poloxalene | Organic compounds | Organoheterocyclic compounds | Epoxides | Not Available | Details |
| Ponazuril | Organic compounds | Benzenoids | Benzene and substituted derivatives | Diphenylethers | Details |
| Pradofloxacin | Organic compounds | Organoheterocyclic compounds | Quinolines and derivatives | Quinoline carboxylic acids | Details |
| Prostalene | Organic compounds | Lipids and lipid-like molecules | Fatty Acyls | Fatty acid esters | Details |
| Robenacoxib | Organic compounds | Benzenoids | Benzene and substituted derivatives | Aniline and substituted anilines | Details |
| Ronnel | Organic compounds | Organic acids and derivatives | Organic thiophosphoric acids and derivatives | Thiophosphoric acid esters | Details |
| Rotenone | Organic compounds | Phenylpropanoids and polyketides | Isoflavonoids | Rotenoids | Details |
| Roxarsone | Organic compounds | Benzenoids | Phenols | Nitrophenols | Details |
| Selamectin | Organic compounds | Phenylpropanoids and polyketides | Macrolides and analogues | Milbemycins | Details |
| Squalene | Organic compounds | Lipids and lipid-like molecules | Prenol lipids | Triterpenoids | Details |
| Sulfachlorpyridazine | Organic compounds | Benzenoids | Benzene and substituted derivatives | Benzenesulfonamides | Details |
| Sulfaethoxypyridazine | Organic compounds | Benzenoids | Benzene and substituted derivatives | Benzenesulfonamides | Details |