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Updated: Mar 29, 2026
In Vivo Confocal Microscopy: A Standard Operating Procedure for the Detection of Demodex Mites at the Eyelid Margin
Published on: July 3, 2025
First Detection of Human- and Dog-Associated Demodex Mites (Acari, Arachnida) in Southern European Wolves (Canis
Natalia Sastre1, Manena Fayos2, Luca Rossi3
1Servei Veterinari de Genètica Molecular, Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
Abstract:
Demodex mites are common commensals of mammalian skin, but under certain conditions, they can cause severe skin diseases. This study analyzed the presence, diversity, and phylogenetic relationships of Demodex species in two wolf subspecies from southern Europe to determine whether species-level differences exist between wild and domestic canids after thousands of years of divergence. A total of 1400 hair samples from 140 wolves were analyzed using a real-time PCR (qPCR) targeting mitochondrial 16S rRNA and nuclear 18S rRNA genes. Overall, 37.1% (52/140; 95% CI: 29.0-45.9%) of wolves were positive for Demodex DNA, with a higher prevalence in Italian (46%) than in Iberian (36%) wolves. The lip and chin areas were the most reliable sampling sites. Four Demodex species were identified in wolves: D. injai and D. canis (associated with dogs), and D. folliculorum and D. brevis (associated with humans). Co-infestations involving multiple Demodex species were recorded for the first time in wild canids. These results challenge the long-held belief of strict host specificity in Demodex mites. The discovery of Demodex species associated with both humans and dogs in wolves supports the idea that host-switching and ecological interactions have occurred throughout the evolution of canids and humans. Such cross-species transfers may have taken place during the early domestication of dogs, representing a plausible scenario compatible with our data. However, given the isolated history of the two southern wolf populations, it is more probable that these findings result from recent interspecific transmission events, likely facilitated by ecological overlap with domestic animals and human environments. Future genomic studies will be essential for clarifying the evolutionary relationships within the genus Demodex and its host associations.
Insights
Demodex mites, commonly found on mammals, were identified in wolves, including species typically found in dogs and humans. This challenges the idea of strict host specificity and suggests recent cross-species transmission events.
Area of Science:
- Parasitology
- Canid Ecology
- Molecular Phylogenetics
Background:
- Demodex mites are common skin commensals in mammals.
- Under certain conditions, Demodex can cause severe skin diseases.
- Host specificity of Demodex species in wild canids is poorly understood.
Purpose of the Study:
- To analyze Demodex mite presence, diversity, and phylogenetic relationships in two European wolf subspecies.
- To investigate potential species-level differences between wild and domestic canid-associated Demodex.
- To explore host-switching and evolutionary interactions within the Demodex genus.
Main Methods:
- Real-time PCR (qPCR) targeting mitochondrial 16S rRNA and nuclear 18S rRNA genes.
- Analysis of 1400 hair samples from 140 wolves (Italian and Iberian subspecies).
- Identification of Demodex species based on genetic markers.
Main Results:
- 37.1% of wolves tested positive for Demodex DNA, with higher prevalence in Italian wolves.
- Four Demodex species were identified: D. injai, D. canis (dog-associated), D. folliculorum, and D. brevis (human-associated).
- Co-infestations with multiple Demodex species were observed for the first time in wild canids.
Conclusions:
- The findings challenge the long-held belief of strict host specificity in Demodex mites.
- The presence of dog and human-associated Demodex species in wolves suggests host-switching and recent interspecific transmission.
- Ecological overlap with domestic animals and human environments likely facilitates these cross-species transfers.
