Invasive pulmonary aspergillosis of horses: an association with acute enteritis.

This research investigated invasive pulmonary aspergillosis in horses, establishing a correlation between this ailment and acute enteritis, with a strong indication that Salmonella infection may be a primary cause for most of the cases. The study gives insight into the effects of multiple conditions and drug treatments, which might predispose horses to pulmonary aspergillosis.

Overview of the Research

• The research identified invasive pulmonary aspergillosis in 19 horses, which is a severe condition that affects the lungs and respiratory system, often associated with the fungus Aspergillus.
• In 16 out of these cases, fungal (mycotic) lesions were associated with inflammation of the intestine and colon (enterocolitis).
• Furthermore, 14 out of the cases appeared to be a result of Salmonella infection, a bacterial infection that affects the intestinal tract.

Pulmonary Lesions

• The study discovered that these lesions in the lungs comprised multifocal areas of acute necrosis, which means death of most or all of the cells in an organ or tissue due to disease.
• Other conditions observed were leukocytoclastic vasculitis, an inflammation of small blood vessels, and thrombosis (clotting within a blood vessel) with fibrinosuppurative inflammation surrounding mycelial masses. Mycelial masses refer to the vegetative part of a fungus consisting of a mass of branching, thread-like hyphae.
• Likewise, thromboemboli with fungi were found in the brain and kidneys of three cases. Thromboemboli refers to a detached intravascular solid, liquid, or gaseous mass that is carried by the blood to a site distant from its point of origin.

Predisposing Conditions

• The study also identified several factors that seemed to predispose horses to this fungal infection. These include corticosteroid therapy, disseminated neoplasms (spread of cancer), hepatitis, pleuritis (inflammation of the pleura, usually causing chest pain and shortness of breath), and peritonitis (inflammation of the peritoneum).

Conclusion of the Research

• The research concluded that a weakened immune system and invasion of Aspergillus fungi due to damaged intestines are more important in causing equine pulmonary aspergillosis than simply inhaling spores. This suggests that focus should be on overall health management and the gastrointestinal health of the horse, rather than only on respiratory hygiene.