EFFECTIVENESS
Cattle: The effectiveness of Pradalex for the treatment of BRD associated with Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Mycoplasma bovis was demonstrated in a multi-site natural infection field study conducted in the U.S. A total of 630 commercial, mixed-breed male and female calves with clinical BRD were enrolled. Calves were administered a single subcutaneous dose of either Pradalex at 10 mg/kg body weight or an equivalent volume of sterile saline. Calves were evaluated for clinical success on Day 10. The success rate of Pradalex-treated calves (49.7%) was statistically significantly different (p = 0.0089) and numerically greater than that of saline-treated calves (25.6%) (based on back-transformed least squares means). No adverse events associated with Pradalex administration were reported in the study.
Swine: The effectiveness of Pradalex for the treatment of SRD associated with Bordetella bronchiseptica, Glaesserella (Haemophilus) parasuis, Pasteurella multocida, Streptococcus suis, and Mycoplasma hyopneumoniae was demonstrated in a multi-site, natural infection field study conducted in the U.S. A total of 1,200 castrated male and female growing pigs with clinical SRD were enrolled. At enrollment, pigs were administered a single intramuscular dose of either Pradalex at 7.5 mg/kg body weight, or an equivalent volume of sterile saline. Pigs were evaluated for clinical success on Day 7. The success rate of Pradalex-treated pigs (45.2%) was statistically significantly different (p=0.0274) and numerically greater than that of the saline-treated pigs (34.2%) (based on least squares means). No adverse events associated with Pradalex administration were reported in the study.
A total of 72 castrated male and female growing pigs were enrolled in an M. hyopneumoniae-induced challenge model study. Pigs were inoculated with a field strain of M. hyopneumoniae once daily for three consecutive days. Three days after the final inoculation, pigs were administered a single intramuscular dose of either Pradalex at 7.5 mg/kg body weight, or an equivalent volume of sterile saline. Pigs were euthanized and necropsied on Day 10. There was a significant difference (p=0.0002) in the mean total lung lesion score in favor of Pradalex-treated pigs (11.7%) compared to the saline-treated pigs (33.1%).
TARGET ANIMAL SAFETY
Cattle: Pradalex was evaluated in a margin of safety study with 32 healthy, weaned calves. Calves were randomized to four treatment groups: 0X (saline control), 1X (10 mg pradofloxacin/kg), 3X (30 mg pradofloxacin/kg) and 5X (50 mg pradofloxacin/kg). Calves were administered subcutaneous doses on Days 0, 4, and 8. All calves remained clinically normal throughout the in-life study and survived until scheduled necropsy on Day 9. Injection site swelling was noted in the 1X and 5X groups. Neutrophil counts, monocyte counts, and creatine kinase levels were generally higher in the treated groups, and this was attributed to inflammation and tissue damage at the injection sites. At necropsy, injection site lesions consisting of discoloration and edema, with microscopically visible hemorrhage, inflammation, and necrosis were reported in most treated animals. No signs of fluoroquinolone-induced arthropathy were reported. No other clinically significant adverse effects related to Pradalex were reported.
Pradalex was also evaluated in a margin of safety study focusing on pathologic changes to the testes and epididymides in 16 healthy, weaned bull calves. Calves were randomized to four treatment groups: 0X (saline control), 1X (10 mg pradofloxacin/kg), 3X (30 mg pradofloxacin/kg) and 5X (50 mg pradofloxacin/kg). Calves were administered subcutaneous doses on Days 0, 4, and 8. All calves remained clinically normal throughout the study and survived until scheduled castration on Day 9. Injection site swelling was noted in the 1X, 3X, and 5X groups. In the 1X group, 3 of 4 calves developed mild to moderate subcutaneous swellings, one resolved by 6 hours post-treatment and two were not resolved by the end of the study. No abnormal macroscopic or microscopic pathology in the testes or epididymides was reported.
Swine: Pradalex was evaluated in a margin of safety study with 32 healthy, weaned, crossbred pigs. Pigs were randomized to four treatment groups: 0X (saline control), 1X (7.5 mg pradofloxacin/kg), 3X (22.5 mg pradofloxacin/kg) and 5X (37.3mg pradofloxacin/kg). Pigs were administered intramuscular doses on Days 0, 2, and 4. All pigs remained clinically normal throughout the in-life study and all pigs survived until scheduled necropsy on Day 11. Aspartate aminotransferase (AST) and creatine phosphokinase (CK) showed elevations and statistically significant treatment by day interactions in Pradalex-treated pigs. These were attributed to inflammation and tissue damage at the injection sites and the values returned to normal by Day 10. There were no other clinically relevant effects on the remaining clinical pathology results. At necropsy, the only macroscopic and microscopic lesions attributable to Pradalex were related to tissue injury at the intramuscular injection sites. No signs of fluoroquinolone-induced arthropathy were reported. No other clinically significant adverse effects related to Pradalex were reported.