Clinical follow-up in fattening bulls affected by Bovine Respiratory Disease (BRD) after pharmacological treatment with Tulathromycin and Ketoprofen: clinical score and ultrasonographic evaluations

Bovine respiratory disease (BRD) is recognized as one of the most important disease in beef industry because it may negatively influence animal welfare and farm economy. An early diagnosis is necessary to improve prognosis and outcome, as well to provide for specific management treatment for the affected animals. The aim of this study is to assess the feasibility of the ultrasonographic technique as diagnostic method for BRD in fattening bulls after pharmacological treatment with tulathromycin and ketoprofen. Sixty Limousine fattening bulls of 10.23 ± 1.37 months’ age belonging to a single farm were enrolled in this study. Animals were divided into two groups according to ultrasonographic score (US score) of lungs: Group C or control group (US score<3; 29 animals), and Group D or disease group (US score≥3; 31 animals). Both groups received a clinical examination and a TUS (thoracic ultrasonography) at time 0 (T0; day of restocking) and time 7 (T7; +21 days). Furthermore, group D received additional clinical examinations and TUS at time 1 (T1; day of diagnosis and treatment), time 2 (T2; +1 day), time 3 (T3; +2 days), time 4 (T4; +3 days), time 5 (T5; +7 days), and time 6 (T6; +14 days). Statistical differences between groups were evaluated by parametric and not-parametric test. The lung lesions such as total areas of hepatization and fluid alveolograms were measured and analyzed with mixed regression models over time. The two groups showed a significant difference both in US score and clinical symptoms (respiratory score, nasal and ocular discharges and rectal temperature) when comparing T1 of group D with T0 of group C. Over the time, the treatment of group D was effective in reducing the US score and rectal temperature after 2 and 1 days, respectively, while ocular discharges was reduced after 2 days. The ultrasound evaluation of the general health status showed an improvement after 7 days from treatment. However, a reduction of total areas of hepatization and fluid alveolograms were evidenced in 3 days. In conclusion, the pulmonary ultrasound has been evidenced as a feasible and sensitive tool both for BRD early diagnosis and treatment effectiveness evaluation in fattening bulls.