First report of Neotrombicula inopinata infestation in domestic cats from Portugal

A review on trombiculiasis: An underreported parasitosis that affects humans and animals, including world distribution, clinical findings, associated pathogens, prophylaxis and identification methods

Chigger mites comprise three families: Trombiculidae, Leeuwenhoekiidae and Walchiidae, with over 3,000 species worldwide. Their life cycle includes six stages, and the larvae are parasites, while the other stages are free-living predators. Once attached to a host, the larvae spend several days feeding on the host's epithelial tissue, forming the stylostome. An inflammatory reaction can be formed during larval feeding, known as trombiculiasis or trombiculosis. In this study, we provide a literature review using 123 scientific articles on the cases of trombiculiasis in animals and humans reported in different biogeographical regions, including 29 countries and 30 different chigger species, with all the information compiled in the Supplementary material. This review aims to increase the visibility of this disease and group of mites, so that physicians and veterinarians can become more aware of the disease and include the causative agent in differential diagnoses. We also offer knowledge on mounting and control methods in order to improve mite identification for future research. Lastly, the prophylaxis and control methods in cases of infestations and associated pathogens are mentioned.

First report of Ericotrombidium ibericense in domestic dogs

PURPOSE

Larval stages of trombiculid mites infest a wide variety of wild and domestic animals. The most common clinical signs related with the presence of these parasites are alopecia, crusts, erythema, excoriation, erosion, papules, pustules and vesicles. Most of trombiculid infestations may not be perceived by the clinician due to their small size. Although Ericotrombidium ibericense has been recorded on cats, it has not been found on dogs.

METHODS

In August 2019, three domestic dogs presenting pruritic dermatological lesions in the ventral area of the body and interdigital spaces were presented at a veterinary clinic in Santarém, central Portugal. Trombiculid mites were extracted from the skin and preserved in 70% ethanol. Specimens were prepared in slides with Hoyer's medium and observed with optical microscopy.

RESULTS

After morphological examination of the specimens, mites were identified as E. ibericense (Acariformes: Trombiculidae).

CONCLUSIONS

Most of the trombiculids recorded in European clinical practice are generally identified as Neotrombicula autumnalis by default, since, in most cases, mites are not examined morphologically. This is the first record of E. ibericense in domestic dogs. More studies are needed to evaluate the distribution of these mites in Portugal. Veterinary clinicians must be aware of this parasitosis, as trombiculids can cause exuberant clinical signs, but are often misdiagnosed.