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Case Reports
. 2025 Mar 20;70(2):72.
doi: 10.1007/s11686-025-01012-3.

First Reported Case of Accidental Gastric Myiasis Caused by Gasterophilus Larvae in a Gray Wolf

Rabiga Uakhit  1   2   3 , Christian Bauer  2   4 , Ainura Smagulova  1   3 , Vladimir Kiyan  5   6
Affiliations
Case Reports

First Reported Case of Accidental Gastric Myiasis Caused by Gasterophilus Larvae in a Gray Wolf

Rabiga Uakhit et al. Acta Parasitol. .

Abstract

Background: Myiasis is the infestation of living vertebrates by larvae ("maggots") of dipterous flies. These include the Gasterophilus species (Oestridae). Their larvae are obligate endoparasites of equids, and their third instar larvae remain in specific areas of the gastrointestinal tract for many months. Non-equids are unsuitable hosts for Gasterophilus spp. However, their larvae have occasionally been found in the digestive tracts of carnivores and scavengers; this is known as accidental myiasis.

Methods: A gray wolf (Canis lupus) hunted near a settlement in northern Kazakhstan in February 2023 was necropsied. Its stomach, which was otherwise empty, contained four cylindrical, cream-coloured maggots, approximately 15 mm long, attached to the gastric mucosa.

Results: The maggots were identified morphologically as second and third instar Gasterophilus larvae and molecularly as Gasterophilus pecorum.

Conclusion: This is the first reported case of accidental gastric myiasis in wolves. The causative species, Gasterophilus pecorum, is a common parasite of equids in Asian countries. The larvae must have survived the ingestion process intact and remained attached to the wolf's stomach wall with cephalopharyngeal hooks for a prolonged period of time, lasting from more than half a day to several days.

Keywords: Gasterophilus Spp.; Gastric myiasis; Kazakhstan; Wolf.

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Conflict of interest statement

Declarations. Ethics Approval: The study (collection of hunted wild carnivores, including wolves) was approved by the Animal Ethics Committee, as shown in the extract from Protocol No. 1 (24 July 2019). The study adhered to the World Medical Association Code of Ethics (Declaration of Helsinki) for Animal Experimentation ( http://ec.europa.eu/environment/chemicals/lab_animals/legislation_en.htm ), which ensures that all animal procedures are done ethically. Competing Interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Third instar Gasterophilus sp. larva collected from the stomach of a gray wolf, ventral view. Scale bar = 5 mm
Fig. 2
Fig. 2
Maximum likelihood tree based on the mitochondrial cox2 gene region from the Gasterophilus pecorum larva in this study (red dot) and several Gasterophilus spp. available in GenBank. Numbers along the branches show bootstrap values resulting from different analyses in percent; scale: estimated number of nucleotide substitutions per site; species name after the GenBank accession no.; blue triangle: outgroup
See this image and copyright information in PMC

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