BackgroundLeishmaniosis, zoonosis that produces significant public health impacts, is caused by Leishmania infantum. Canines are the main domestic reservoir and, besides humans, other species of mammals could be infected when living in endemic areas. In this study, we detected equine Leishmania infantum infections in a canine visceral leishmaniosis transmission area and evaluated the clinical, haematological, biochemical and oxidative stress disorders. This study was conducted in Uruguaiana, Rio Grande do Sul, south of Brazil. Peripheral blood samples were collected from 124 animals (98 horses and 26 dogs) of both genders and several breeds after they underwent general and dermatologic examinations.ResultsTwenty five Leishmania infantum infected animals (20.16%), 14 horses and 11 dogs were detected by PCR (Polymerase Chain Reaction) amplification of kinetoplast DNA regions with 96% homology to Leishmania infantum (GenBank Accession No. L 19877.1). The clinical and haematological alterations of infected equines were skin lesions, nodules, lymphadenopathy, decreased levels in red blood cells and haematocrit (p < 0.05) and increase in urea serum concentration (p < 0.05), while CVL presented a decrease in red blood cells counts (p < 0.05), increase in lymphocytes (p < 0.05), and decrease in neutrophil-lymphocyte ratio (p < 0.05). Oxidative stress markers of plasma protein carbonyl and plasma lipid peroxidation were not statistically significant (p > 0.05) in both species.ConclusionsTo our knowledge, this has been the first leishmaniosis equine survey performed in south of Brazil, caused by Leishmania infantum that were able to initially identify haematological and biochemical changes in the species, even in asymptomatic animals. We present evidence supporting those findings of haematological and biochemical changes could be related to infection. Surprisingly, the clinical manifestations of equine infection were similar to those found in canine visceral leishmaniosis. The equine population could be play an important role in the cycle of leishmaniosis in south Brazil and consequently indicates a great risk of public health. This evaluation of infected animals is important to establish the clinical and laboratory parameters involved in the disease progression.

The aim of this study was to characterize Leishmania spp. from canine and feline samples using Polymerase Chain Reaction (PCR)- Restriction Fragment Length Polymorphism (RFLP). It was conducted in the southern region of Brazil, located at border crossings to Argentina and Uruguay. Samples were collected from 116 dogs (Canis lupus familiaris) and 89 cats (Felis catus). The PCR was performed to screen for an LT1 fragment from kinetoplast DNA (kDNA) target gene, and positive samples were subjected to a second PCR for an internal transcribed spacers (ITS1) region from ribosomal DNA (rDNA) target. RFLP was performed using the Haemophilus aegyptius (HAE III) restriction endonuclease (Fermentas ®). Positive samples by PCR ITS1 were sequenced and deposited in NCBI GenBank, and a phylogenetic analysis was developed. We found that 12.9% (15/116) of the samples from dogs were positive. All the 89 cat samples were negative. Positive samples were tested against Leishmania reference strains presenting different patterns in PCR-RFLP, and these samples showed bands denoting similarity to the standard species of Leishmania infantum, proven through sequencing and phylogenetic analysis. The RFLP technique, alone, was shown to be feasible for practical application and confirmation of the involved Leishmania spp.