Canine visceral leishmaniasis (CVL) is the major source of human visceral leishmaniasis. To control the spread of this disease, early and accurate detection of infected dogs is critical but challenging. The serological diagnosis of CVL remains problematic because there are no reliable commercially available tests. Most laboratories use enzyme-linked immunosorbent assay or the indirect immunofluorescent antibody test. These tests use Leishmania chagasi recombinant antigens K39 or K26 assembled with either gold-labelled Staphylococcus aureus protein A or protein G from Streptococcus pyogenes. In this work, we propose the development, optimization and standardization of a lateral flow immunoassay (LFIA) based on functionalized colored particles and a specific recombinant antigen, as a visual in situ method for the diagnosis of CVL. The following analysis variables were considered: (i) the concentration of the latex-protein complex; (ii) the dilution of the serum; (iii) the composition of the employed buffers; (iv) the nominal capillary flow time through the nitrocellulose membrane; (v) the concentration of reagents fixed in the test and control lines; (vi) the particle size of the colored latex; and (vii) the conjugation method. Then, the obtained strips were evaluated as a visual diagnostic tool based on a panel of positive and negative sera. It was observed that because of its simplicity and performance the LFIA test is a quick and reliable alternative for the diagnosis of CVL either in conventional laboratories or for remote areas where laboratories are not readily accessible for conventional assays.

犬内脏利什曼病（CVL）是人类内脏利什曼病的主要来源。为了控制这种疾病的传播，尽早而准确地检测出感染的狗是至关重要的，但具有挑战性。CVL的血清学诊断仍然存在问题，因为尚无可靠的市售检测方法。大多数实验室使用酶联免疫吸附试验或间接免疫荧光抗体试验。这些测试使用与黄金标记的金黄色葡萄球菌蛋白A或化脓性链球菌蛋白G组装的利什曼原虫查加斯重组抗原K39或K26。在这项工作中，我们提出了基于功能化有色颗粒和特定重组抗原的侧向流免疫测定（LFIA）的开发，优化和标准化，作为视觉原位诊断CVL的方法。考虑了以下分析变量：（i）乳胶-蛋白质复合物的浓度；（ii）稀释血清；（iii）所用缓冲器的组成；（iv）通过硝酸纤维素膜的名义毛细管流动时间；（v）在测试和控制管线中固定的试剂浓度；（vi）彩色乳胶的粒度；（vii）结合方法。然后，基于阳性和阴性血清组，将获得的试纸条作为视觉诊断工具进行评估。