Pulmonary hemorrhage in horses seroreactive to leptospirosis in Rio de Janeiro, Brazil.

The letter to the editor discusses pulmonary hemorrhage in horses seroreactive to leptospirosis in Rio de Janeiro, Brazil. It emphasizes the frequency of leptospirosis related respiratory disorders, specifically pulmonary hemorrhage, in horses and suggests that more research is needed especially in tropical areas where the disease is more prevalent.

Leptospirosis Associated Respiratory Disorders in Horses

In this article, the authors focus on the less frequently discussed respiratory illnesses associated with leptospirosis in horses, such as:

• Pulmonary Hemorrhage (PH)
• Pneumonitis

They provide examples of recorded instances of PH in an aborted foal in Rio de Janeiro, Brazil, and the diagnosis was confirmed through PCR testing of the foal’s hemorrhagic thoracic fluid.

Study on Training Horses

In a separate study, the team investigated 84 adult training horses. They found that:

• Pulmonary hemorrhage was significantly more common in seroreactive horses when compared to seronegative ones.
• The condition was also more severe among the seroreactive horses.
• Seroreactive horses were also 4.26 times more likely to present with PH.

Treatment of Leptospirosis in Horses

With regard to treatment, the researchers discuss their experiences with:

• Procaine Penicillin G combined with streptomycin.
• The antibiotic therapy cefquinome used on only one foal in another study, which resulted in ‘good results’.
• The use of 25mg/kg dosage in 18 adult seroreactive horses which showed improvement in the grade of their hemorrhage.

Consideration of Leptospirosis in Diagnosis of Acute Respiratory Distress

While the incidents in the research were recorded in Brazil, researchers suggest the possibility of such occurrences even in temperate countries like Belgium, although the frequency is higher in tropical areas. Therefore, they agree with the notion that leptospirosis must be considered as a potential cause during the differential diagnosis of acute respiratory distress in horses, irrespective of their age or location.