Table II.
Antimicrobials used at least once in cows or calves before weaning from July 2013 through June 2014 in 98 cow-calf herds.
| Cows | Number of herds | Percent | Calves | Number of herds | Percent |
|---|---|---|---|---|---|
| Antimicrobials used (category of importance to human healthb) | |||||
| Aminoglycosides (II) | 1 | 1% | |||
| Aminoglycosides (topical agents) (III) | 2 | 2% | |||
| Cephalosporins (1st generation) (II) | 3 | 3% | |||
| Cephalosporins (3rd generation) (I) | 7 | 7% | Cephalosporins (3rd generation) (I) | 14 | 14% |
| Fluoroquinolones (I) | 8 | 8% | |||
| Florfenicol (III) | 27 | 28% | Florfenicol (III) | 79 | 81% |
| Lasalocid (IV) | 2 | 2% | Lasalocid (IV) | 1 | 1% |
| Macrolides (II) | 19 | 19% | Macrolides (II) | 23 | 24% |
| Monensin (IV) | 10 | 10% | Monensin (IV) | 6 | 6% |
| Neomycin-sulfamethazine (II) | 11 | 11% | |||
| Penicillin (II) | 36 | 37% | Penicillin (II) | 19 | 19% |
| Polymyxinsa (I) | 14 | 14% | Polymyxinsa (I) | 1 | 1% |
| Sulfa boluses (III) | 5 | 5% | Sulfa boluses (III) | 43 | 44% |
| Sulphonamides (III) | 2 | 2% | |||
| Tetracyclines (III) | 78 | 80% | Tetracyclines (III) | 54 | 55% |
| Trimethoprim-sulfadoxine (II) | 7 | 7% | Trimethoprim-sulfadoxine (II) | 30 | 31% |
| Any antimicrobial use | 93 | 95% | Any antimicrobial use | 93 | 95% |
| Importance to human healthb | |||||
| Category I | 20 | 20% | Category I | 19 | 19% |
| Category II | 49 | 50% | Category II | 55 | 59% |
| Category III | 85 | 87% | Category III | 93 | 95% |
| Category IV | 11 | 11% | Category IV | 7 | 7% |
| Route of administration | |||||
| In-feed products | 14 | 14% | In-feed products | 9 | 9% |
| Injectable products | 92 | 94% | Injectable products | 92 | 93% |
| Intra-mammary product | 22 | 22% | Intra-mammary product | 1 | 1% |
| Intra-uterine bolus | 6 | 6% | Oral boluses | 51 | 52% |
| Topical wound spray | 2 | 2% | Water-soluble product | 5 | 5% |
a
Contained in intra-mammary preparation (Special Formula 17900-Forte Suspension).
b
Importance to human health as categorized by Health Canada (15). Category I includes drugs of very high importance to human health, Category II includes drugs of high importance, Category III are medium importance, and Category IV are low importance.