First report of straelensiosis in red foxes (Vulpes vulpes)

Abstract

Background-Straelensia cynotis, a trombidioid larval mite, was identified as a cause of nodular dermatitis in dogs in Southern Europe. It has been suggested that red fox (Vulpes vulpes) is a natural host for S. cynotis. However, no case has been reported in this species. Objective-To describe three suspected cases of straelensiosis in red foxes. Animals-Three juvenile wild red foxes from Portugal. Results-Erythematous papules and nodules were found in the head, neck and limbs of these foxes with no associated pruritus. In skin biopsies, well-preserved larval mites were found within dilated hair follicles. These follicular lesions were multifocal and consisted of a degenerative and necrotic area nearby the parasite's mouthparts with marked pseudoepitheliomatous hyperplasia and perifollicular mucinosis. These features are considered pathognomonic in S. cynotis infestations in dogs. Treatment and outcome are outlined. Conclusions and clinical importance-To the best of the authors' knowledge, the present case series documents the first known occurrence of nodular dermatitis by Straelensia spp. in red foxes. This new evidence may corroborate participation of the red fox in the life cycle of S. cynotis.

Feline straelensiosis: Clinical and histopathological description of a case and first genetic characterisation of Straelensia cynotis

“…Although foxes have been regarded as the natural host of the parasite and the main source of infestation for the accidental hosts, most of the evidence supporting this hypothesis was circumstantial 2 . Furthermore, the parasite was reported for the first time in foxes in 2020 8 . In the case described here, the cat was living in an area frequented by foxes and also by a variety of other wild animals.…”

“…2 Furthermore, the parasite was reported for the first time in foxes in 2020. 8 In the case described here, the cat was living in an area frequented by foxes and also by a variety of other wild animals. Straelensiosis has now been reported in dogs from other southern European countries, including Spain, 3 Portugal 6 and Italy.…”

“…The need for molecular tools to identify S. cynotis was later emphasised when it was recognised as being the only valid method to confirm foxes as wild reservoir of the parasite. 8 Herein, we report the first molecular characterisation of S. cynotis obtained from a cat and a dog, together with the data set required for genetic comparison to past and/or future reports of the parasite. Blast analysis revealed 99.82% similarity between the specimens collected from dog and cat with histopathologically confirmed straelensiosis.…”

“…Owing to the absence of prior molecular identification and characterisation of the parasite, the aetiological agent was presumed to be the same species in all reported hosts based on its morphological features. The need for molecular tools to identify S. cynotis was later emphasised when it was recognised as being the only valid method to confirm foxes as wild reservoir of the parasite 8 …”