Scedosporium prolificans infection associated with arthritis and osteomyelitis in a horse.

A type of fungus called Scedosporium prolificans has been linked with arthritis and bone infections in a 6-year-old racehorse, according to this research paper.

Research Background and Case Details

• The research paper focuses on an equine subject, a Thoroughbred racehorse, who was initially believed to be suffering from an inflammation of the tendon between the bones, known as the interosseous tendon. Despite receiving treatment, the horse’s condition didn’t significantly improve.
• Following another examination called an ‘arthrocentesis’ of the left metacarpophalangeal joint (the joint connecting the metacarpal bones of the hand or forefoot with the phalanges of the fingers or toes), the horse’s joint swelled severely. Upon conducting radiography, the researchers discovered that there had been a significant degradation of certain bones, including the distal end of the third metacarpal bone, the proximal sesamoid bones, and the proximal end of the proximal phalanx.

Postmortem Findings and Conclusion

• The horse unfortunately did not respond to the administered treatment and was consequently euthanized for humane reasons.
• An autopsy was conducted post-euthanasia, revealing serious erosive arthritis and degenerative osteomyelitis (a severe bone infection) in the left metacarpophalangeal joint. Researchers gathered swab specimens from the ulcerated lesions of the articular cartilage for microbial culture.
• The results from the test showed that the infection was caused by the fungus Scedosporium prolificans – a recently identified opportunistic pathogen that primarily affects both humans and animals. In humans, this fungus usually causes localized invasive infections that target musculoskeletal tissues and are commonly triggered by penetrating trauma or surgical incision.
• In people with compromised immunity, this fungus could also lead to severe, life-threatening systemic infection. The study also notes that the challenging characteristic of this fungus is its resistance to nearly all existing antimycotic (antifungal) agents.

Relevance of Findings

• This case study gives valuable insights into equine health, specifically for racehorses, and highlights the potential threat posed by Scedosporium prolificans. It provides evidence of the fungus’s ability to cause severe joint and bone infections, leading to debilitating conditions like arthritis and osteomyelitis.
• This research primarily warns veterinary medical communities about the dangers presented by this type of fungus and the need for further studies to develop an effective antimycotic treatment.