Pulmonary aspergillosis associated with acute enteritis in a horse.

This research investigates a case of invasive pulmonary aspergillosis in a horse tied to a diarrheal illness. The 8-year-old mare featured in this study developed the fungal lung infection after suffering from diarrhea, laminitis, and a nasal discharge, which were eventually traced back to an infection from the bacterium Ehrlichia risticii.

Background of the Research

• The research article focuses on an autopsy examination conducted on an 8-year-old Quarter Horse that had previously shown signs of diarrhea, laminitis, and bilateral nasal discharge.
• It was found that the horse had invasive pulmonary aspergillosis, a fungal infection that affects the lungs and can lead to systematic infections and death if not treated.

Diagnosis Process

• The diagnosis pointed to an infection with a bacterium named Ehrlichia risticii.
• This verdict was based on clinical assessments such as signs of diarrhea and fever.
• Furthermore, laboratory tests showed a high level of antibodies against E. risticii in the serum (1:2,560), evidencing the horse’s immune system responding to the bacterial exposure.
• Additionally, multiple cultures taken from the fecal and colonic specimens were negative for Salmonella, ruling out this bacterium as the cause of the symptoms.

Pathological Mechanisms

• The researchers suggested possible pathological events that led to the development of the horse’s pulmonary aspergillosis.
• The mechanisms proposed include two key pathways: fungal intrusion of the intestinal tract, and compromised immunity and tissue deterioration due to severe enterocolitis.

Role of Aspergillus Exposure

• The researchers also assume the horse’s exposure to a significant amount of Aspergillus organisms could have been a critical factor in the manifestation of this disease.
• Aspergillus is a fungi variety that can cause severe lung infections, especially in individuals with weakened immune systems or existing lung diseases like the horse in this investigation.