Table 1.
Antimicrobial drug usage in the study population.
| Drug (dosage) | Drug Class | Primary Reason for Use | Number of Animals treated (%) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Pen A | Pen B | Pen C | Pen D | Pen E | Pen F | Pen G | Pen H | |||
| Tylosin phosphate (11 mg/kg diet dry matter)a |
Macrolide | Liver abscess prevention | 244 (100) |
281 (100) |
152 (100) |
189 (100) |
230 (100) |
230 (100) |
265 (100) |
150 () |
| Tulathromycinb
(2.5 mg/kg BWc) |
Macrolide | BRDd Treatment | 15 (6.1) |
16 (5.7) |
12 (7.9) |
3 (1.6) |
19 (8.3) |
3 (1.3) |
8 (3.0) |
5 (3.3) |
| Oxytetracyclinee
(20 mg/kg BW) |
Tetracycline | BRD Treatment | 1 (0.4) |
1 (0.4) |
43 (28.3) |
9 (4.8) |
6 (2.6) |
2 (0.9) |
13 (4.9) |
10 (6.7) |
| Oxytetracycline and Flunixin meglumineb
(30 mg/kg BW and 2 mg/kg BW) |
Tetracycline | BRD Treatment | 0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
1 (0.4) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
| Danofloxacin mesylateb
(8 mg/kg BW) |
Fluoroquinolone | BRD Treatment | 0 (0.0) |
4 (1.4) |
1 (0.7) |
0 (0.0) |
4 (1.7) |
7 (3.0) |
2 (0.8) |
0 (0.0) |
| Enrofloxacinb
(7.7 mg/kg BW) |
Fluoroquinolone | BRD Treatment | 0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
2 (0.8) |
0 (0.0) |
| Ceftiofur sodiume
(1 mg/kg BW) |
β-lactam | BRD Treatment | 0 (0.0) |
0 (0.0) |
2 (1.3) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
| Ceftiofur crystalline free acidb
(6.6 mg/kg BW) |
β-lactam | BRD Treatment | 0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
0 (0.0) |
4 (1.5) |
1 (0.7) |
aThis AMD was in all rations of all cattle for the duration of the feeding period.
bEach treated animal received a dose that persisted in target tissues at effective therapeutic concentrations for 3 days, according to the drug label.
cBW = body weight.
dBRD = bovine respiratory disease.
eEach treated animal received a dose that persisted in target tissues at effective therapeutic concentrations for 1 day, according to the drug label.