In a 12 months old Cavall Pirinenc Català breed horse carcass the presence of abundant nodular structures disseminated on the peritoneum and abdominal fat was observed. Inside the cysts, nematode larvae were found.

These nematodes are compatible with the large strongyles group (Strongylidae family) The parasitological study allowed to identify them as Strongylus edentatus larvae (specifically the larval phase L5 also known as immature adults).

These are intestinal parasites that present during their cycle stages of larval migration outside the intestine during which they cause lesions on the liver and other abdominal structures such as the omentum, liver ligaments and diaphragm, often associated with hemorrhages, and generating, as in the case we are dealing with, eosinophilic granulomas. Once mature, the larvae return to the intestine where adults will lay their eggs, causing edema and/or haemorrhagic nodules or plates on the wall of the caecum and the colon.

It is not a zoonosis.

When opening the abdominal fat cysts, larvae of up to 4 cm in length are observed.

Male and male larvae of Strongylus edentatus.

Observation of a female larvae of Strongylus edentatus under the microscope.

Detail of the buccal capsule of a larva of Strongylus edentatus.

Comparison between the buccal capsules of Strongylus edentatus and Strongylus vulgaris. The second is the most common nematode parasite in horses and is characterized by causing arteritis in the mesenteric circulation that can cause arterial infarcts and colic in the large intestine.