Review of Corynebacterium (Rhodococcus) equi lung abscesses in foals: pathogenesis, diagnosis and treatment.

The research article discusses the growing significance of Corynebacterium (Rhodococcus) equi in causing bronchopneumonia and lung abscesses in foals and the potential effectiveness of a targeted antibiotic treatment in controlling the disease.

Overview of Corynebacterium (Rhodococcus) equi Infections in Foals

• The study first identifies the Corynebacterium (Rhodococcus) equi bacterium as a rising concern because it leads to bronchopneumonia and lung abscesses in foals.
• This bacterium is resilient, managing to survive within macrophages, which are white cells in our immune system. This ability allows it to evade normal pulmonary defense mechanisms, especially in foals with weakened immune systems.
• Past instances of this infection have led to high mortality rates of up to 80% among affected foals, in large part due to inappropriate treatment methods.

Effective Therapeutic Approach

• The study then discusses a preferred therapeutic approach for treating this bacterium. Stress is laid on the importance of selecting lipid-soluble antibiotics that can infiltrate inside the cell, where the bacteria reside.
• An effective combination treatment that has been used on foals since 1981 is mentioned, consisting of erythromycin (at a dosage of 25 mg/kg three times daily) and rifampicin (5 mg/kg twice daily).
• The foals treated this way mostly had radiographic proof of widespread lung abscessation and, in all instances, the existence of the C equi bacterium was confirmed by culturing tracheal aspirates.
• The treatment period varied between four and nine weeks.

Observations and Success Rate

• Occasional side effects, such as mild gastritis and diarrhea were observed during the treatment, however, they were not severe enough to necessitate stopping the therapy.
• No other negative side effects were reported.
• The therapy was found to be exceptionally effective, with an over 80% success rate as seen through the normalization of chest radiographs and plasma fibrinogen levels in treated foals.