Table 3.
Assignment of DDDbovCA and DCDbovCA values for antimicrobial agents used non-systemically through the intramammary, intrauterine, and topical routes for cattle in Canada.
| Antimicrobial agent | Combined with another antimicrobial agent in products? | Antimicrobial class | Category according to Health Canada | DDDbovCA (mg per animal per day) | DCDbovCA (mg per animal per course) |
|---|---|---|---|---|---|
| Antimicrobial agents used through the intramammary route in cows during the lactation | |||||
| Benzylpenicillin (Penicillin G) Procaine | Combined with dihydrostreptomycin, novobiocin, and polymyxin B sulfate | Beta-lactamase sensitive penicillins | II | 60 | 90 |
| Cefapirin | No | First-generation cephalosporins | II | 400 | 400 |
| Ceftiofur | No | Third-generation cephalosporins | I | 125 | 250 |
| Dihydrostreptomycin | Combined with benzylpenicillin procaine, novobiocin, and polymyxin B sulfate | Aminoglycosides | II | 100 | 150 |
| Novobiocin | Combined with benzylpenicillin procaine, dihydrostreptomycin, and polymyxin B sulfate | Aminocoumarins | Not categorized | 150 | 225 |
| Pirlimycin | No | Lincosamides | II | 50 | 250 |
| Polymyxin B sulfate | Combined with benzylpenicillin procaine, dihydrostreptomycin, and novobiocin | Polymyxins | I | 6 | 9 |
| Antimicrobial agents used through the intramammary route in cows at drying-off | |||||
| Benzylpenicillin (Penicillin G) procaine | Combined with novobiocin | Beta-lactamase sensitive penicillins | II | 48 | 480 |
| Cefapirin | No | First-generation cephalosporins | II | 120 | 1,200 |
| Ceftiofur | No | Third-generation cephalosporins | I | 200 | 2,000 |
| Cloxacillin | No | Beta-lactamase resistant penicillins | II | 200 | 2,000 |
| Novobiocin | Combined with benzylpenicillin procaine | Aminocoumarins | Not categorized | 160 | 1,600 |
| Antimicrobial agents used through the intrauterine route in cows | |||||
| Cefapirin | No | First-generation cephalosporins | II | 500 | 500 |
| Gentamicin sulfate | No | Aminoglycosides | II | 200 | 200 |
| Oxytetracycline | No | Tetracyclines | III | 2,500 | 2,500 |
| Sulfanilamide | Combined with sulfathiazole | Sulfonamides | III | 2,880 | 2,880 |
| Sulfathiazole | Combined with sulfanilamide | Sulfonamides | III | 480 | 480 |
| Antimicrobial agents used through the topical route in cattle | |||||
| Chlortetracycline | No | Tetracyclines | III | 147 | 441 |
| Sulfanilamide | Combined with sulfathiazole | Sulfonamides | III | 444 | 2,220 |
| Sulfathiazole | Combined with sulfanilamide | Sulfonamides | III | 444 | 2,220 |
DDDbovCA, Canadian Defined Daily Dose for cattle (in mg/animal/day); DCDbovCA, Canadian Defined Course Dose for cattle (in mg/animal/course).