Abstract
Leishmania spp., protozoal parasites belonging to the Trypanosomatidae family, are the cause of a common zoonotic illness. Dogs are the main reservoirs of the parasites, which play a considerable role in infecting humans and other hosts. This report explains lymph node involvement by amastigotes of the viscerotropic Leishmania species in a dog who suffered from ulcerative nodules and generalized eczematous and exfoliative dermatitis (erythroderma).
A 2-year-old male dog with evident acute skin lesions and ulcerative nodules on the face was referred to a small animal hospital in Mazandaran province, Iran. The animal had started showing signs ten days prior and was lethargic and lost appetite. In order to detect Leishmania parasites, the popliteal lymph node was sampled for the cytological examination and also polymerase chain reaction (PCR) based on the ITS-1 region of the ribosomal DNA gene. Also, a blood sample was collected to determine hematological and biochemical parameters. As a result, Leishman bodies were seen both inside and outside of macrophages when light microscopy was performed on the lymph node sample stained with Giemsa. Laboratory findings revealed mild leukocytosis, lymphocytosis, neutrophilia, low hematocrit. hyperglobulinemia, hyperproteinemia, hypoalbuminemia, declined albumin/globulin ratio, and hyperglycemia. The PCR and sequencing results confirmed the presence of Leishmania in the popliteal lymph node. According to the molecular analysis, L. infantum was the causative agent of leishmaniasis in this case.
Cutaneous leishmaniasis is prevalent in humans and dogs in Iran. In most cases, L. tropica and L. major are the major causative agents of this form of leishmaniasis, and the lesions are confined. In this report, a generalized skin disease was evident. In addition, hematological and biochemical parameters supported a visceral form of leishmania infection in the animal. Because L. infantum is a more dangerous species than the other types for dogs and specifically humans, our report should be considered to control the infection. This report is significant as this unusual form of visceral leishmaniasis in the dog raises concerns about the possibility of zoonotic transmission and may threaten public health.