Peer-reviewed veterinary case report
A case of Setaria equina in a 13-year-old, UK-resident mare.
- Journal:
- Veterinary parasitology, regional studies and reports
- Year:
- 2026
- Authors:
- Healy, S R et al.
- Affiliation:
- The Royal Veterinary College · United Kingdom
- Species:
- horse
Plain-English summary
A 13-year-old mare living in the UK was found to have a rare infection caused by a type of parasite called Setaria equina, which is usually spread by mosquitoes. This infection was discovered during a postmortem examination after the mare had passed away. The adult worms were located in her abdominal cavity, and tests were done to confirm their identity. While these parasites are not typically harmful when they are adults, they can cause problems if their larvae move to other parts of the body. Even though cases like this are uncommon in the UK, veterinarians should keep this infection in mind, especially when dealing with eye problems in horses, regardless of whether the horse has traveled abroad.
Abstract
Setaria equina is a species of filarial nematode parasite transmitted by mosquitoes, which infects horses and other equids. Adult worms reside in the abdominal cavity with apparently little pathogenic significance, but larvae can migrate to other regions of the body with resulting clinical disease. Cases in the UK are rare, with the last published report in 2001. A recent case of S. equina infection was detected in a 13-year-old, UK-resident mare during postmortem examination in Hertfordshire, UK. Adult worms were collected from the abdominal cavity, their DNA extracted and subjected to PCR and sequencing analysis for identity confirmation. Although rare, clinical seteriasis should be considered by clinicians, especially in ocular disease cases, even without overseas travel history.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/41651623/