Abstract
Onychogryphosis is one of the main clinical findings in dogs with visceral leishmaniasis (VL); however, research focusing on the subungual area of infected dogs is scarce. This study aims to assess the subungual area of dogs with VL that presented or not onychogryphosis by means of histopathological analyses and immunohistochemical studies (parasite burden). The third digit of the thoracic and pelvic limbs of Leishmania infantum naturally infected dogs was collected regardless of sex, breed or age. The animals were split into two groups, dogs with onychogryphosis (G1; n=7) and without onychogryphosis (G2; n=9). The digits were evaluated in four areas (dorsal epidermis/dermis, ventral epidermis/dermis, dorsal matrix/dermis and ventral matrix/dermis). All lesions observed (mononuclear inflammatory infiltrate, vacuolar degeneration of basal keratinocytes, dermoepidermal clefting and pigmentary incontinence) were present in both groups, being more severe in the digits of G1 group. Immunostaining of the amastigote forms of Leishmania infantum were observed in the different areas of the digit, with statistical difference between the dorsal epidermis/dermis area and the dorsal matrix/dermis of G1 group. In conclusion, the main histopathological alteration of the digit of dogs with VL is mononuclear inflammatory infiltrate and parasite burden, especially in cutaneous tissue adjacent to the nail matrix. This aspect can influence the onychogryphosis development, due to the presence of the parasite and by inflammatory mediators released in the nail microenvironment.
Highlights
Visceral leishmaniasis (VL) is an anthropozoonosis broadly disseminated around the world, which affects human beings, dogs and wild animals [1] and whose etiologic agent in the American continent is the protozoan Leishmania infantum [2]
Onychogryphosis is the excessive growth of nails, and is among the main clinical findings in dogs with VL, being reported in the proportions of 63.1% [6], 40% [7] and 55% [8]
Among the histopathological findings at the subungual area of the dogs investigated in this study, chronic dermatitis was representative in the four digit areas of dogs with onychogryphosis, and a little less frequent in dogs without onychogryphosis
Summary
Visceral leishmaniasis (VL) is an anthropozoonosis broadly disseminated around the world, which affects human beings, dogs and wild animals [1] and whose etiologic agent in the American continent is the protozoan Leishmania infantum [2]. Mosquitos of the species Lutzomyia longipalpis and Lutzomyia cruzi are the vectors involved in disease transmission [3]. The clinical signs of VL are varied, such as generalized lymphadenomegaly, progressive weight loss, splenomegaly, hepatomegaly, skin alterations, eye lesions, kidney diseases, neurological disorders, and onychogryphosis [5]. Onychogryphosis is the excessive growth of nails, and is among the main clinical findings in dogs with VL, being reported in the proportions of 63.1% [6], 40% [7] and 55% [8]. Some authors correlate nail overgrowth to the presence of the parasite in the nail matrix [2]. A weak amplification of the parasite DNA was detected in the digit of a dog with VL [7]. The literature investigating onychogryphosis pathogens in dogs with VL is scarce
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
