Laboratory tests for diagnosing and monitoring canine leishmaniasis

A longitudinal study on the detection of anti-Leishmania antibodies in a captive European mink (Mustela lutreola) population and their correlation with serum protein electrophoresis

Leishmaniosis, caused by Leishmania infantum and transmitted by sand flies, is a significant zoonotic disease. Dogs are primary reservoirs, but other domestic animals, such as cats and ferrets, and wild species, including Eurasian otters and European mink, can be hosts. This study focused on European mink, a critically endangered species, investigating the seroprevalence of L.infantum antibodies and its correlation with serum protein profiles over 2021-2024. A total of 68 captive minks in Spain were monitored, yielding 105 serum samples. ELISA tests identified 44 seropositive samples (41.9 %), with seroprevalence varying annually. While no significant association was found between seropositivity and age, gender, or body condition, seropositivity correlated significantly with the year of collection. Some animals exhibited fluctuating antibody levels across sampling periods. Serum protein electrophoresis analyzed 96 samples, revealing that L.infantum seropositivity significantly affected total protein concentrations, β-globulins, γ-globulins, and albumin:globulin ratio. Variations were also observed in specific protein fractions among both seropositive and seronegative minks. These findings highlight European mink's potential epidemiological role in L.infantum transmission. Monitoring antibody levels and protein profiles in captive populations can inform conservation strategies and disease management efforts.

qPCR as a Tool for the Diagnosis of Visceral and Cutaneous Leishmaniasis: A Systematic Review and Meta-Analysis

INTRODUCTION

Ensuring accuracy in the diagnosis of leishmaniasis is crucial due to the myriad of potential differential diagnoses. Given the inherent limitations of serological techniques, real-time polymerase chain reaction (qPCR) emerges as a superior alternative. Furthermore, parasitological methods, conventionally regarded as the gold standard owing to their high specificity, encounter challenges concerning sensitivity and invasiveness for patients. In this context, the present study aims to assess, via meta-analysis, the performance of qPCR in diagnosing visceral and cutaneous leishmaniasis.

METHOD

This meta-analysis encompassed studies published between January 2011 and December 2022, sourced from six databases (PubMed, LILACS, Scopus, Scielo, EMBASE, and Web of Science), utilizing the keywords "qPCR," "molecular diagnosis," and "leishmaniasis." Epidemiological studies focusing on the efficacy of qPCR for leishmaniasis diagnosis were included. Data such as study demographics, geographic locations, sampling techniques, and the number of positive qPCR results were aggregated and analyzed to derive overall positivity rates, sensitivity, and specificity values associated with qPCR. Heterogeneity analysis was conducted on the data to select appropriate models, and the collective efficacy data of qPCR were illustrated in forest plots.

RESULTS

Fifty-four studies met all inclusion criteria. The positivity rates for human visceral and cutaneous leishmaniasis were 27.07% (95% CI: 17.81-36.33%) and 60.40% (95% CI: 30.23-90.57%), respectively. In cases of visceral leishmaniasis in dogs, cats, and wild animals, the positivity rates were 26.55% (95% CI: 21.40-31.70%), 0.92% (95% CI: 0.09-1.75%), and 28.98% (95% CI: 21.86-35.10%), respectively. Analysis of the selected studies revealed high overall sensitivity and specificity values achieved with qPCR, at 91.08% (95% CI: 81.77-100.39%) and 98.08% (95% CI: 97.13-99.03%), respectively.

CONCLUSION

This study indicates that qPCR is a highly sensitive and specific tool, adequately suitable for the diagnosis of human visceral and cutaneous leishmaniasis, as well as visceral leishmaniasis in animals.

Updating the epidemiology of canine leishmaniosis in the United Kingdom through the use of electronic health data

Dogs infected with Leishmania infantum have been increasingly reported in the UK mostly related to imported/travelled dogs. Up-to-date epidemiologic data are essential for a better control of this zoonotic disease in such emerging areas. This study aimed for the first time, to estimate the percentage and temporal variation of dog and cat samples testing positive for L. infantum infection at commercial diagnostic laboratories, and to describe the travel history of positive dogs and cats positive to leishmaniosis in a network of UK veterinary practices. Leishmania infantum serology and PCR data were collected by the Small Animal Veterinary Surveillance Network (SAVSNET) from five UK national veterinary diagnostic laboratories between 2010 and 2022 and were analysed. In addition, electronic health records (EHRs) were collected from 251 veterinary practices across the UK between March 2014 and September 2022. Text mining tools were used to identify cases compatible with clinical leishmaniosis as recorded in the clinical narratives; these were subsequently manually validated. Data from a total of 25,327 diagnostic samples (25,201 from dogs and 126 from cats) were analysed including 20,517 sera tested by either quantitative ELISA or IFAT, and 4810 by PCR. Leishmania infantum antibodies were detected in 39.7 % of tested dog samples and 1.07 % of cat samples. In dogs, seropositivity increased from 2013 to 2022. Leishmania DNA was only detected by PCR in samples from dogs (11.8 %). A total of 368 dogs with canine leishmaniosis (CanL) were identified from clinical narratives. Of these, 189 had either visited, or were rescued/imported from, Spain, Greece, Cyprus and other southern European countries. Among factors associated with CanL in the UK canine population, dogs between 3 and 6 years of age were 4.71 times more likely to have CanL than those two years or younger. In addition, there was an increased risk of having recorded CanL clinical cases from 2017 to 2022, compared to 2014. Southeast of England was the UK region that accounted for the highest number of CanL cases (34.51 %). This study provides recent trends in Leishmania infection in dogs in the UK, identifies risk factors and countries likely associated with imported cases, and provides important insights to help plan and monitor national intervention strategies.

Efficacy of a combination of nucleotides and lactoferrin in maintaining stable or improving the clinical picture and laboratory findings of leishmaniotic dogs: A randomized controlled study

This prospective, randomized, controlled, therapeutic study aimed to evaluate the efficacy of a product containing nucleotides and lactoferrin in maintaining or improving the clinical picture and laboratory findings of canine leishmaniosis (CanL). The safety and tolerance of this combination were also assessed. Forty Leishmania infantum-seropositive dogs, not requiring leishmanicidal and/or leishmaniostatic treatment, were enrolled in the study and randomized into treatment (TG) and placebo (CG) groups. Products A (containing nucleotides and lactoferrin) and B (placebo) were blindly administered to TG and CG, respectively, as palatable tablets at a rate of 1 tablet per 10 kg of weight once every 24 h for 6 months. Following inclusion (T0), dogs were followed up after 3 (T90) and 6 (T180) months. At each time point, for all animals enrolled physical examination and laboratory tests (complete blood count, biochemical panel including C-reactive protein [CRP] and ferritin, and serum protein electrophoresis) were performed. The immunofluorescence antibody test to detect antibodies for L. infantum (T0, T180), Ehrlichia canis (T0, T90, and T180), and Anaplasma phagocytophilum (T0, T90, and T180) was executed. A CanL-dedicated clinical score, using a validated scale from 0 (i.e., absence of clinical signs) to 19, was assigned. Four dogs (n=2 in TG, n=2 in CG) did not complete the study. No statistically significant differences in CanL clinical score were observed between CG and TG at T0, T90 and T180. Both TG and CG showed significant variations in anti-L. infantum antibody titres (p=0.0001 and p=0.004, respectively). In TG, antibody titres decreased in 77.8 %, increased in 5.5 %, and remained stable in 16.7 % of dogs, while in CG, decreased in 27.8 %, increased in 50 %, and remained stable in 22.2 % of dogs. During the study, CRP and ferritin remained stable in TG and significantly increased in CG. At T180, 9 out of 18 dogs (50 %) enrolled in the CG, and 1 out of 18 (5.6 %) enrolled in the TG, developed an active form of leishmaniosis. No side effects were reported in any patient included. In conclusion, a 6-month oral administration of a supplement containing nucleotides and lactoferrin was effective in maintaining a stable clinical score, improving antibody titres and potentially reducing the progression from non-active to active forms in L. infatum seropositive dogs. Furthermore, the product was well-tolerated, easy to administer, and free of side effects.

Serum protein electrophoresis in European mink (Mustela lutreola): reference intervals and comparison of agarose gel electrophoresis and capillary zone electrophoresis

BACKGROUND

Knowledge of reference intervals for blood analytes, including serum protein fractions, is of great importance for the identification of infectious and inflammatory diseases and is often lacking in wild animal species.

MATERIAL AND METHODS

Serum samples were obtained from European minks enrolled in the breeding program (n = 55). Agarose gel electrophoresis (AGE) and capillary zone electrophoresis (CZE) were used to separate and identify protein fractions. Albumin, α1, α2, β, and γ-globulins fractions were identified in all mink sera by both electrophoresis methods. Reference intervals (90% CI) were determined following the 2008 guidelines of the Clinical Laboratory Standard Institute. The methods were compared using Passing-Bablok regression, Bland-Altman analysis, and Lin's concordance correlation.

RESULTS

A significant bias was found between methods for α1, α2, and γ-globulin. Lin's concordance correlation was considered unacceptable for α1, α2, and β-globulins. Differences for gender between methods were found for albumin and α2-globuins, which were higher for males than females. γ-globulins were higher for adults than young minks using both methods; however, α1 and α2-globulins were lower.

CONCLUSION

Both methods are adequate for identifying serum protein disorders, but the AGE and CZE methods are not equivalent. Therefore, reference intervals for each technique are required.

Preliminary field evaluation of indirect ELISA test using the recombinant antigen rLicNTPDase-2 for serodiagnosis of canine leishmaniasis in Colombia

Leishmaniasis is a significant public health concern, with dogs as the primary reservoir in urban scenarios and facilitating transmission. Diagnosing infected dogs is a crucial step for public health interventions, and the development of new diagnostic platforms can significantly enhance efforts in various regions worldwide. Given the limited availability of diagnostic methods in Colombia, this study evaluates the effectiveness of an Indirect Enzyme-Linked Immunosorbent Assay (ELISA) based on the recombinant protein rLicNTPDase-2 to detect Leishmania in infected dogs. Serum samples were collected from dogs in both endemic and non-endemic areas and classified as natural standards based on prior parasitological diagnoses. The results revealed 24 true positives (TP) and 9 true negatives (TN). Subsequently, the test was then validated with samples from symptomatic and asymptomatic animals, alongside the standards, yielding a specificity of 96 %, a sensitivity of 81 %, efficiency of 90.6 %, a positive predictive value of 92.8 %, and a negative predictive value of 89.6 %. The positive likelihood ratio (RV+) was 20, while the negative likelihood ratio (RV-) was 0.19, indicating high relevance and a robust clinical utility. The area under the curve (AUC) was 1.00, suggesting that the test has excellent discriminatory ability, significantly deviating from the reference diagonal. This is further supported by the significant difference(p < 0.0001) between TN and TP results determined by Fisher's exact test. Involving 163 animals showed 47 % positive and 46 % negative results with a significant difference (p < 0.05) in the mean optical density (OD) values between positive and negative samples. These findings indicate that the ELISA test effectively differentiates between positive and negative samples based on OD values. This study suggests that ELISA based on the recombinant antigen rLicNTPDase-2 could serve as a viable alternative for the serodiagnosis of leishmaniasis in canines in Colombia.

Clinical significance of blood cell ratios in healthy and sick Leishmania infantum-seropositive dogs

BACKGROUND

The accuracy of blood cell ratios (BCRs) as cost-effective and easily accessible diagnostic and prognostic markers of inflammatory conditions has been investigated in veterinary medicine in recent years.

METHODS

Neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), and platelet-to-lymphocyte (PLR) ratios were studied in 195 dogs clinically evaluated and tested for anti-Leishmania infantum (Li) antibodies (Li-seronegative (Li-), n = 10; Li-seropositive clinically healthy (Li+healthy), n = 100; Li-seropositive with clinical and/or clinicopathological abnormalities (Li+sick), n = 85). The Li+sick dogs were classified in LeishVet stages IIa/IIb (Li+IIa/IIb) (n = 66) and III/IV (Li+III/IV) (n = 19). BCR relationships with LeishVet clinical stage, antibody levels, and serum protein electrophoretic fraction concentrations were investigated.

RESULTS

Higher NLR values were found in Li+, Li+healthy, and Li+IIa/IIb sick dogs compared to Li- dogs (P < 0.001). Higher NLR and MLR were found in Li+sick (NLR, P < 0.001; MLR, P = 0.034) and Li+III/IV dogs (NLR, P < 0.001; MLR, P = 0.005) compared to Li- dogs, and in Li+III/IV dogs (NLR, P = 0.002; MLR, P < 0.001) compared to Li+healthy. All three BCRs were higher in Li+sick (NLR, MLR, P < 0.001; PLR, P = 0.023) and Li+IIa/IIb dogs (NLR P < 0.001; MLR P = 0.001; PLR, P = 0.012) compared to Li+healthy dogs. The BCRs failed to distinguish dogs with moderate (Li+IIa/IIb) and severe or very severe disease (Li+III/IV). BCRs demonstrated weak positive correlations with serum globulin fractions and antibody levels, and weak negative correlations with serum albumin level were found. Li+sick dogs presenting hypoalbuminemia showed higher MLR ratios (P = 0.001) than those with normal albumin values.

CONCLUSIONS

This study shows that BCR measures provide useful information for differentiating antibody-positive healthy and sick dogs at diagnosis. Dogs with hypoalbuminemia showed higher MLR values despite monocytosis being very rare.

Evaluation of urinary podocin and nephrin as markers of podocyturia in dogs with leishmaniosis

BACKGROUND

Renal disease is the main cause of death in canine leishmaniosis. Detection of an active glomerular injury is important to identify early renal damage and to prevent the development of chronic kidney disease. Podocyturia can indicate renal injury, and podocyte-associated molecules such as podocin and nephrin can be used to identify podocyturia. The purpose of the study was to evaluate urinary podocin and nephrin concentrations in dogs with leishmaniosis as markers of podocyturia.

METHODS

A total of 35 healthy dogs and 37 dogs with leishmaniosis were enrolled in the study. Dogs with leishmaniosis were classified according to the staging of the International Renal Interest Society (IRIS). Urinary podocin and nephrin concentrations were measured in all dogs with a validated enzyme-linked immunosorbent assay test and normalized to creatinine (uPoC and uNeC, respectively). The demographic, clinical, and laboratory data from both groups were analyzed and compared. Subsequently, the laboratory results were analyzed and compared according to IRIS staging in dogs in IRIS stage I and dogs in IRIS stage II + III + IV. The Pearson's correlation test evaluated the relationship between urinary markers of podocyturia.

RESULTS

Compared with healthy dogs, lower urinary podocin [median values (IQR): 15.10 (11.75-17.87) ng/ml versus 8.63 (7.08-13.56) ng/ml; P < 0.01] and nephrin [median values (IQR): 3.2 (3.62-5.43) ng/ml versus 2.67 (2.06-3.44) ng/ml; P < 0.01] were found in infected sick dogs. No significant differences were observed in the uPoC and uNeC between the two groups. Urinary nephrin and podocin concentrations were higher in healthy dogs and in dogs in IRIS stage I (both P < 0.05) compared with dogs in IRIS stages II + III + IV. No significant differences were found for uPoC and uNeC between healthy dogs and dogs with leishmaniosis in different IRIS clinical stages.

CONCLUSIONS

Dogs with leishmaniosis had a low concentration of podocin and nephrin in more advanced IRIS clinical stages, when kidney disease was more severe compared with healthy dogs and dogs in IRIS stage I with mild disease. Urinary nephrin was detectable for the first time in healthy non-infected dogs.

Exploring the Relationship between Canine Paraoxonase-1 (PON-1) Serum Activity and Liver Disease Classified by Clinico-Pathological Evaluation

Paraoxonase-1 (PON-1), a liver-synthesized enzyme, acts as a negative acute-phase reactant during systemic inflammation in dogs. Given the hepatic synthesis of this enzyme, the presence of liver diseases may influence PON-1, thus affecting its reliability as a biomarker for inflammatory/oxidative systemic diseases. The aim of this study is to investigate PON-1 activity variations among dogs suspected of liver injury or failure, evaluating the influence of hepatic diseases on PON-1 activity. A total of one-hundred-sixty dogs were retrospectively enrolled and categorized into three groups based on clinical presentation and laboratory results: control (C = 20), suspected liver injury (INJ = 114), and suspected liver failure (FAIL = 26). The INJ group was further divided into subgroups based on the severity of the alanine aminotransferase (ALT) increase. Both the INJ and FAIL groups were further divided based on serum macroscopic appearance. The PON-1 activity was quantified using a paraoxon-based method, which is already validated in dogs. No significant difference in PON-1 activity was observed between the C and INJ groups, despite a significant increase in the subgroups with moderate and severe elevations of ALT. The dogs with icteric serum exhibited decreased PON-1 activity, while lipemic serum was associated with an increased PON-1 activity. A significant reduction in PON-1 activity was noted in the FAIL group, compared to both C and INJ groups (p < 0.0001), regardless of serum appearance. Given the retrospective nature of this study, additional evaluations (e.g., histopathology, imaging) were not performed. The results obtained here suggest the importance of interpreting PON-1 activity cautiously in dogs with suspected liver disease.

Relapses in canine leishmaniosis: risk factors identified through mixed-effects logistic regression

BACKGROUND

Canine leishmaniosis (CanL), caused by Leishmania infantum, is an important vector-borne parasitic disease in dogs with implications for human health. Despite advancements, managing CanL remains challenging due to its complexity, especially in chronic, relapsing cases. Mathematical modeling has emerged as a powerful tool in various medical fields, but its application in understanding CanL relapses remains unexplored.

METHODS

This retrospective study aimed to investigate risk factors associated with disease relapse in a cohort of dogs naturally infected with L. infantum. Data from 291 repeated measures of 54 dogs meeting the inclusion criteria were included. Two logistic mixed-effects models were created to identify clinicopathological variables associated with an increased risk of clinical relapses requiring a leishmanicidal treatment in CanL. A backward elimination approach was employed, starting with a full model comprising all potential predictors. Variables were iteratively eliminated on the basis of their impact on the model, considering both statistical significance and model complexity. All analyses were conducted using R software, primarily employing the lme4 package, and applying a significance level of 5% (P < 0.05).

RESULTS

This study identified clinicopathological variables associated with an increased risk of relapses requiring a leishmanicidal treatment. Model 1 revealed that for each 0.1 increase in the albumin/globulin ratio (A/G) ratio, the odds of requiring treatment decreased by 45%. Conversely, for each unit increase in the total clinical score (CS), the odds of requiring treatment increase by 22-30%. Indirect immunofluorescence antibody test (IFAT) was not a significant risk factor in model 1. Model 2, incorporating individual albumin and globulins values, showed that dogs with high IFAT titers, hyper beta-globulinemia, hypoalbuminemia, anemia, and high CS were at increased risk of relapse. Both models demonstrated a good fit and explained a substantial amount of variability in treatment decisions.

CONCLUSIONS

Dogs exhibiting higher CS, dysproteinemia, anemia, and high IFAT titers are at increased risk of requiring leishmanicidal treatment upon clinical relapse in CanL. Regular monitoring and assessment of risk factors prove essential for early detection of relapses and effective intervention in CanL cases. The contrasting findings between the two models highlight the complexity of aspects influencing treatment decisions in this disease and the importance of tailored management strategies to improve outcomes for affected dogs.

A case report of acute claudication due to vena cava thromboembolism in a dog naturally infected with Leishmania Infantum

Canine leishmaniosis is a vector-borne disease caused by Leishmania infantum, and clinical manifestations of infection range from absent or severe to fatal and result from immune-mediated mechanisms. In dogs, the most common clinical signs of leishmaniosis include skin lesions and lymphadenomegaly. However, the presence of other nontypical signs has been described, and diagnosing these cases can be challenging. The aim of the present short communication was to describe the impact of the formation of circulating immunocomplexes due to L. infantum in a dog with leishmaniosis affected by a massive venous thrombus of the caudal vena cava and external iliac veins. On admission, the dog presented bilateral cutaneous vasculopathy of the thigh and renal disease due to L. infantum infection. Two weeks after starting anti-Leishmania treatment based on meglumine antimoniate and allopurinol administration, the animal developed acute claudication of the hind limbs with the presence of a thrombus in the caudal vena cava and the external iliac veins and a high level of circulating immunocomplexes detected by enzyme-linked immunosorbent assay. Exacerbation of the humoral immune response, along with deposition of circulating immune complexes in the tissues and the concurrent presence of kidney and liver damage, might have contributed to an imbalance in haemostasis in this patient. Future studies should evaluate and analyse the pathological mechanisms contributing to thrombosis in dogs with leishmaniosis.

The erythrocyte sedimentation rate and other markers of inflammation in cats tested for Leishmania infantum and feline immunodeficiency virus antibodies

BACKGROUND

In endemic areas, Leishmania infantum and feline immunodeficiency virus (FIV) co-infection occurs in cats, and may favour a progressive course of feline leishmaniosis. Abnormalities in serum protein fractions have been reported, but inflammation markers have scarcely been studied. Erythrocyte sediment rate (ESR) is a marker of inflammation that is poorly used in veterinary medicine, but it has been evaluated in EDTA blood using a recently introduced automatic device. We studied ESR and a pool of feline markers of inflammation (MoI) in cats L. infantum (Li+) and/or FIV antibody-positive (Li+FIV+/FIV+) with the aims (a) to evaluate ESR as MoI in cats with the infectious and clinical conditions considered and (b) to provide data about a pool of MoI never investigated in the feline infections studied and in other cat diseases before.

METHODS

This prospective controlled study included 35 study group cats (Li+, n = 20; FIV +, n = 8; Li+FIV+, n = 7) and ten healthy antibody-negative control cats. Clinical findings at physical examination and selected clinical pathological abnormalities related to inflammation were statistically analysed in relation to the infectious status and ESR values.

RESULTS

ESR values were higher in Li+, FIV+, and Li+FIV+ cats compared with control cats, and 40% of the study group cats had ESR values above the reference interval (RI). ESR positively correlated with some positive MoI and negatively with some negative MoI studied. Additionally, a higher prevalence of ESR values above the RI has been detected in cats with hypoalbuminemia or hypergammaglobulinemia and higher ESR values were measured in cats with serum protein electrophoresis (SPE) fraction abnormalities. Correlations were also found with erythrocytes, hemoglobin, hematocrit and some erythrocyte indices. FIV+ and Li+FIV+ cats had a higher prevalence of increased ESR values, and almost all had SPE abnormalities and more severe clinical presentations compared with Li+ cats.

CONCLUSIONS

Abnormal levels of MoI were found in almost all parameters studied, particularly in FIV+ and Li+FIV+ cats. Also, ESR can be used as a marker of inflammation in cats with L. infantum and/or FIV infection.

Distribution of and Relationships between Epidemiological and Clinicopathological Parameters in Canine Leishmaniosis: A Retrospective Study of 15 Years (2009-2023)

Leishmaniosis is a vector-borne disease caused by protozoan parasites of the genus Leishmania, which are zoonotic and have an important impact on animal and public health globally. Between 2009 and 2023, blood samples from domestic dogs with clinical suspicion of leishmaniosis were received from 286 veterinary medical centres throughout mainland Portugal. An enzyme-linked immunosorbent assay (ELISA) was utilised to detect antibodies against Leishmania infantum antigens. Additionally, a complete blood count and tests for total proteins, urea, creatinine and alanine aminotransferase, as well as protein electrophoresis, were also performed. No significant relationship between sex and breed was observed. The age distribution was bimodal, with the highest prevalence of disease occurring at 2-5 years of age and a secondary peak occurring at 6 years or over (p < 0.001). No statistical correlation was observed between creatinine and urea across the ELISA serological groups. In contrast, both the gamma globulin levels (r = 0.45; p < 0.001) and the albumin/globulin ratio (r = -0.36; p < 0.001) exhibited moderate correlations with the ELISA. These findings support recent seroprevalence studies in dogs, with some geographical areas in Northern Portugal exhibiting the highest values, which may be the result of geographical shifts in parasite circulation due to climate change.

Critically Appraised Topic on Canine Leishmaniosis: Does Treatment with Antimonials and Allopurinol Have the Same Clinical and Clinicopathological Efficacy as Treatment with Miltefosine and Allopurinol, after One Month of Treatment?

The treatment of canine leishmaniosis commonly involves meglumine antimoniate with allopurinol or miltefosine with allopurinol. This study aims to compare the clinical and clinicopathological efficacy at 28-30 days of conventional dosing regimens for both treatments using the critically appraised topic methodology. A comprehensive search across three databases (PubMed, CAB Abstracts, and Web of Science) from March 2004 to September 2023 yielded 16 relevant articles, encompassing 325 ogs treated with meglumine antimoniate and allopurinol, and 273 dogs treated with miltefosine and allopurinol. The findings indicated a significantly higher rate of complete clinical cure in the group treated with meglumine antimoniate and allopurinol. Most dogs in both groups exhibited improvement in clinicopathological alterations after one month of treatment. No significant difference was observed in the number of dogs that showed a negative Leishmania qPCR between the two groups, one month post-treatment. However, quantitative serology results were not commonly reported in the available data and therefore this aspect could not be compared.

Fibroblast growth factor-23 and Alpha-Klotho concentrations in dogs with canine Leishmaniasis

This study aimed to assess the concentrations of Fibroblast Growth Factor-23 (FGF-23) and α-Klotho in healthy dogs and dogs at different stages of Canine Leishmaniasis (CanL), and investigate the changes of these parameters in relation to renal function and calcium‑phosphorus metabolism. A total of 74 dogs (22 healthy and 52 with CanL) of varying ages, sexes, and medium-sized breeds were included. Dogs with CanL were categorized into different stages (Stage I-IV) based on Leishvet recommendations. In addition to routine hematological parameters, plasma FGF-23, serum α-Klotho, urea, creatinine, phosphorus, calcium, parathormone, vitamin D concentrations, and urine protein/creatinine ratio were measured. Data from healthy dogs were compared to dogs with CanL overall and by stage. Dogs with CanL exhibited higher concentrations of FGF-23 (p < 0.05), α-Klotho, and parathormone (p < 0.001), as well as lower concentrations of vitamin D and calcium (p < 0.001). FGF-23 concentration was particularly elevated in Stage IV compared to other stages. However, no significant differences in α-Klotho levels were observed among the stages. FGF-23 levels showed a weak positive correlation with urea and creatinine concentrations and a moderate positive correlation with urine protein/creatinine ratio. This study demonstrated increased levels of FGF-23 and α-Klotho in dogs with CanL for the first time. The increase in FGF-23 levels was more prominent in advanced stages of the disease and correlated with higher urea and creatinine concentrations. These findings may serve as a basis for future diagnostic and therapeutic investigations, contributing to the understanding of the pathophysiology of kidney disease in CanL.

Synthetic Peptides Selected by Immunoinformatics as Potential Tools for the Specific Diagnosis of Canine Visceral Leishmaniasis

Diagnosing canine visceral leishmaniasis (CVL) in Brazil faces challenges due to the limitations regarding the sensitivity and specificity of the current diagnostic protocol. Therefore, it is urgent to map new antigens or enhance the existing ones for future diagnostic techniques. Immunoinformatic tools are promising in the identification of new potential epitopes or antigen candidates. In this study, we evaluated peptides selected by epitope prediction for CVL serodiagnosis in ELISA assays. Ten B-cell epitopes were immunogenic in silico, but two peptides (peptides No. 45 and No. 48) showed the best performance in vitro. The selected peptides, both individually and in combination, were highly diagnostically accurate, with sensitivities ranging from 86.4% to 100% and with a specificity of approximately 90%. We observed that the combination of peptides showed better performance when compared to peptide alone, by detecting all asymptomatic dogs, showing lower cross-reactivity in sera from dogs with other canine infections, and did not detect vaccinated animals. Moreover, our data indicate the potential use of immunoinformatic tools associated with ELISA assays for the selection and evaluation of potential new targets, such as peptides, applied to the diagnosis of CVL.

Comparative Study of Colorimetric In Situ Hybridization and Quantitative Real-Time Polymerase Chain Reaction for Diagnosis of Infection by Leishmania infantum in Dogs in Formalin-Fixed and Paraffin-Embedded Skin

The zoonotic visceral leishmaniasis is caused by the protozoan Leishmania infantum and dogs are reservoirs for this parasite. For the diagnosis of Leishmania at the species level in dogs in formalin-fixed, paraffin-embedded skin (FFPES) samples, colorimetric in situ hybridization (CISH) and quantitative real-time polymerase chain reaction (qPCR) are options, but their sensitivities are not well established. Therefore, the aim of this study was to determine the sensitivity of these two techniques in FFPES for the diagnosis of the L. infantum infection in dogs using culture as the reference standard. The FFPES of 48 dogs with cutaneous infection by L. infantum confirmed by culture and by multilocus enzyme electrophoresis were examined by CISH and qPCR using specific probes for L. infantum. The sensitivities of qPCR, CISH and their combination were, respectively, 77.0%, 58.0% and 83.3%. The sensitivities of qPCR in dogs with and without clinical signs were, respectively, 74.2% and 82.4%. The sensitivities of CISH in dogs with and without clinical signs were, respectively, 61.3% and 52.9%. The CISH and qPCR showed satisfactory sensitivities for the diagnosis of L. infantum in the FFPES of dogs, even in dogs without clinical signs, and their combination increases the sensitivity for this diagnosis.

Clinical importance of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and systemic immune-inflammation index in dogs with leishmaniasis

Leishmaniasis is a zoonotic disease caused by Leishmania spp., impacts multiple systems and organs. While hematological and biochemical profiles aren't definitive for diagnosis, recent studies have identified the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammation index (SII) as predictors of morbidity and mortality in critically ill human and dog patients. This study examined 100 dogs diagnosed with leishmaniasis, categorized by the International Renal Interest Society (IRIS) stages 1-4. Additionally, the dogs were divided based on whether they survived less or more than one year (L1Y and G1Y). Control group consisted of 43 dogs. The NLR increased as the disease progressed (IRIS 1-4), presenting statistically significant differences (P<0.05) when compared to the control group (2,37±2,08) IRIS 3 and 4 (4,59±13,39 and 6,99±12,86, respectively), and G1Y and L1Y (3,60±4,02 and 4,87±5,82, respectively). Significant changes in SII were only evident in short-term survivors (L1Y 951,93±1402) and advanced renal disease cases (IRIS 4 stage 1073,68±1901,09). Conversely, PLR remained largely unchanged. In conclusion, these results suggest that the neutrophil-to-lymphocyte ratio (NLR) and systemic immune-inflammation index (SII) may serve as potential markers for assessing disease progression and prognosis in dogs diagnosed with leishmaniasis.

Nodular pyogranulomatous panniculitis due to Leishmania infantum infection in a domestic ferret (Mustela putorius furo)

Leishmaniosis is a vector-borne disease caused by different Leishmania species and transmitted by phlebotomine sand flies under natural conditions in Europe. Scientific information related to Leishmania infantum in dogs is extensive, where less information is available in cats and other companion animals. Recently, first clinical cases of L.infantum infection in domestic ferrrets (Mustela putorius furo) have been described. However, clinical information on leishmaniosis in this species is limited A 15-month-old male neutered domestic ferret was presented with chronic weight loss and the presence of coalescent, erythematous and firm subcutaneous nodules in the ventral abdominal subcutis. A fine-needle aspiration of these nodules was performed and the cytological examination revealed a granulomatous inflammation with the presence of macrophages contained a number of oval organisms with an eccentric nucleus and pale cytoplasm, compatible with Leishmania spp. amastigotes compatible with Leishmania spp. amastigotes. The nodules were surgically excised and histological examination showed a severe multifocal pyogranulomatous panniculitis. Specific immunohistochemistry and qPCR for L. infantum from excised nodules were positive. Additionally, L. infantum was cultured and isolated from the nodules by a fine-needle aspiration. An in-house Western Blot test for L. infantum was performed in serum sample and a positive result was obtained. This is the first reported case of nodular pyogranulomatous panniculitis due to L. infantum infection in a domestic ferret. Further studies are necessary to determine the relevance of domestic ferrets in the transmission of leishmaniosis. The description of new clinical forms of the disease is important as it can assist veterinarians in identifying these new clinical presentations.

Clinical and Clinico-Pathological Observations of the Erythrocyte Sedimentation Rate in Dogs Affected by Leishmaniosis and Other Inflammatory Diseases

The erythrocyte sedimentation rate (ESR) has been used in canine medicine in several disorders, above all, to evaluate levels of inflammation. This study evaluated the ESR in canine leishmaniosis (CanL) and other inflammatory conditions. Three groups of dogs were examined: CanL affected dogs without clinical signs (INFECTED group, #25) or with clinical signs (SICK group, #43) and dogs affected by acute or acute-on-chronic conditions (OTHER DISEASE group, #65). The ESR was compared with acute phase proteins or reactants either positive or negative (leukogram, fibrinogen, iron, unsaturated iron binding capacity, ferritin, haptoglobin, and albumin) and immunological markers (gamma-globulins, IgG, and IgM). The ESR was higher in the SICK group than in the INFECTED group (median 39 vs. 11 mm/h; p < 0.0001), as well as in the OTHER DISEASE than in the INFECTED groups (median 41 vs. 11 mm/h; p < 0.0001). The ESR appeared outside the reference range for all dogs in the SICK and OTHER DISEASE groups and almost with similar values (mm/h; median 39, 95% CI 31-51 vs. 41, 95% CI 12-87; p > 0.05). The extent of changes in ESR can help to establish the severity of CanL and other inflammatory disorders. As a point-of-care test, the ESR can be used to screen dogs for unhealthy conditions, and its values correlate with the severity of any disease, including CanL.

Clinical validation of circulating immune complexes for use as a diagnostic marker of canine leishmaniosis

Introduction

Canine leishmaniosis (CanL) is a systemic disease that affects dogs. When multiplication of the parasite cannot be controlled, dogs consistently show high levels of antigen and IgG antibodies, which lead to the formation of circulating immune complexes (CIC). Timely intervention to reduce the parasite load and CIC levels is crucial for preventing irreversible organ damage. However, a diagnostic test to quantify CIC levels is currently lacking.

Methods

In this real-world study, we aimed to examine the performance of a new ELISA to measure CIC levels in dogs naturally infected with Leishmania infantum. Thirty-four dogs were treated according to their clinical condition and followed for 360 days. Before (day 0) and after treatment (days 30, 90, 180, 270, and 360), all dogs underwent a physical examination, and blood samples were obtained for CBC, biochemical profile, serum protein electrophoresis and IFAT. Serum PEG-precipitated CIC were determined by ELISA.

Results

Our results indicate higher CIC levels in dogs in advanced disease stages showing higher antibody titres (p < 0.0001, r = 0.735), anemia (p < 0.0001), dysproteinemia (p < 0.0001), and proteinuria (p = 0.004). Importantly, dogs responding well to treatment exhibited declining CIC levels (p < 0.0001), while in poor responders and those experiencing relapses, CIC were consistently elevated. CIC emerged as a robust discriminator of relapse, with an area under the curve (AUC) of 0.808. The optimal cut-off to accurately identify relapse was an optical density of 1.539.

Discussion

Our findings suggest that declining CIC levels should be expected in dogs showing a favorable treatment response. Conversely, in dogs displaying a poor response and recurrent clinical relapses, CIC levels will be high, emphasizing the need for vigilant monitoring. These findings suggest that CIC could serve as a valuable biomarker for disease progression, treatment efficacy, and relapse detection in CanL. Our study contributes to enhancing diagnostic approaches for CanL and underscores the potential of CIC as a complementary tool in veterinary practice. As we move forward, larger studies will be essential to confirm these findings and establish definitive cut-offs for clinical application.

Erythrocyte sedimentation rate in heartworm naturally infected dogs "with or without" Leishmania infantum seropositivity: an observational prospective study

Canine heartworm disease by Dirofilaria immitis and canine leishmaniosis by Leishmania infantum (CanL) are both vector-borne diseases with frequently overlapping endemicity and able to trigger the acute phase response, being characterized by variations in acute phase proteins (APP). Recently, erythrocyte sedimentation rate (ESR), an indicator of inflammation, has gained attention in veterinary medicine, proving useful in several conditions that include CanL active forms in dogs. This study aims to evaluate ESR in heartworm-infected dogs, compare levels with heartworm-infected and L. infantum seropositive dogs as well as clinically healthy dogs, and assess correlations with other laboratory parameters. From October 2022 to January 2023, a prospective observational study was conducted enrolling heartworm-infected (Dirofilaria group) and heartworm-infected L. infantum seropositive (Dirofilaria/Leishmania group) animals subgrouped according to the CanL clinical form (Dirofilaria/Leishmania active and non-active groups). A group of clinically healthy dogs (control group) was also included. For each dog enrolled physical examination and laboratory tests (complete blood count, biochemical panel including APP, serum protein electrophoresis) were performed. Dirofilaria and Dirofilaria/Leishmania groups presented a significantly higher ESR level compared to healthy dogs. Dirofilaria/Leishmania active group had the highest ESR level among the groups considered. Dirofilaria/Leishmania non-active group had an ESR similar to the Dirofilaria group, but significantly higher and lower compared to the control and the Dirofilaria/Leishmania active group, respectively. A significant positive correlation between ESR and C-Reactive Protein has been found in all groups except for the Dirofilaria/Leishmania non-active group. In Dirofilaria/Leishmania active group a strong positive correlation between ESR and gamma globulins percentage as well as a strong negative correlation between ESR and albumin, albumin/globulins ratio were found. Overall, the ESR was confirmed to be an inflammation marker as well as a helpful disease index, being notably increased in heartworm-infected dogs affected by an active form of CanL.

Hyperbetaglobulinemia, anaemia and thrombocytopenia in a domestic ferret (Mustela putorius furo) associated to Leishmania infantum

Leishmaniosis in domestic ferrets is a vector-borne disease caused in Europe by the protozoan parasite Leishmania infantum. There is limited information on clinical signs and laboratory abnormalities in ferrets due to leishmaniosis. This clinical case report described a domestic ferret (Mustela putorius furo) with severe hyperbetaglobulinemia, anaemia, thrombocytopenia, and abnormal renal parameters. A good clinical response following an anti-Leishmania infantum treatment protocol was achieved. However, the presence of pain at the site of injection was the main side effect due to meglumine antimoniate administration. Xanthine crystalluria was not observed in urine sediment with no other urine alterations detected by urine analysis during the follow-up. Initially, clinical signs noted in this ferret could not initially be attributed to leishmaniosis. However, no causes were found that could have caused the hyperglobulinemia in this patient. A reduction of the levels of anti-L. infantum serum antibodies and the concentrations of beta-globulin fraction was detected in this patient after anti-Leishmania treatment administered as well as the disappearance of thrombocytopenia. To extent of the knowledge of leishmaniosis in ferrets, this is the fourth case report of leishmaniosis documented in this species.

Clinical and Laboratory Response of Domiciled Dogs with Visceral Leishmaniasis Treated with Miltefosine and Allopurinol

Canine visceral leishmaniasis (CVL) remains a significant disease worldwide. In Brazil, its treatment is performed using miltefosine, which has demonstrated promising outcomes in dogs. This study represents the first attempt to treat and monitor dogs with CVL in natural conditions over the course of one year. The dogs were divided into two groups: G1 received miltefosine and allopurinol for 28 days, while G2 received miltefosine for 28 days, followed by allopurinol for one year. The follow-up involved clinical, hematological, and biochemical evaluations, as well as the detection of Leishmania DNA in skin and bone marrow samples. By the end of the follow-up, dogs in G2 exhibited improved staging compared to their initial conditions, whereas those in G1 showed worsened staging. Leishmania DNA in skin and bone marrow decreased between 6 and 12 months after treatment. Our observations indicate that the treatment using miltefosine reduces the detection of the parasite in the skin and bone marrow for up to one year following its administration. The continuous use of allopurinol contributes to control of the disease in dogs. These findings provide valuable insights into the response of dogs treated in natural conditions, offering essential information for veterinarians and public health authorities.

Assessment of the diagnostic performance of serological tests in areas where Leishmania infantum and Leishmania tarentolae occur in sympatry

BACKGROUND

Visceral leishmaniosis caused by infection with the zoonotic protozoan Leishmania infantum is a life-threatening disease affecting dogs and humans. The sympatric occurrence of L. infantum and Leishmania tarentolae in an area of southern Italy endemic for canine leishmaniosis, where dogs are also exposed to the latter species, suggests the persistence of herpetophilic L. tarentolae in a non-permissive host, therefore raising questions about the performance of serological diagnostic tests routinely employed.

METHODS

The diagnostic performance of serological tests such as the immunofluorescence antibody test (IFAT), two commercial immunoenzymatic assays (i.e. NovaTec VetLine Leishmania ELISA® and rK39 ICT®) and an in-house enzyme-linked immunosorbent assay (ELISA) was evaluated in healthy dogs seropositive to L. infantum, whereas the only IFAT available was used to detect antibodies to L. tarentolae.

RESULTS

With the IFAT, out of a total of 104 dogs tested, 15 were seronegative for L. infantum of which three were L. tarentolae seropositive' and 89 were L. infantum seropositive. Of the latter 89 dogs, representing the highest proportion of seropositive animals (85.6%) detected by IFAT' 66 were also seropositive for L. tarentolae. Cohen's kappa (κ) agreement coefficient between the IFAT results and those of all the other tests was very low, and the IFAT results were significantly different from those of all the other serological tests as calculated by Cochran's Q-test. Analysis using the Bayesian latent class (Bayes-LCA) showed that the in-house ELISA and IFAT contributed the most towards identifying infected and non-infected dogs, respectively. The IFAT test showed low positive predictive value (59.5%), but high negative predictive value (100%).

CONCLUSIONS

These results demonstrate that the IFAT for L. infantum, although highly sensitive, may not be considered a useful diagnostic test due to its low specificity. Therefore, an accurate serological tool with high specificity is mandatory for avoiding cross-reaction in epidemiological contexts where the two species of Leishmania occur in sympatry.

A blinded, randomized and controlled multicenter clinical trial to assess the efficacy and safety of Leisguard® as an immunotherapeutic treatment for healthy Leishmania infantum-seropositive dogs

BACKGROUND

Domperidone (Leisguard®) is an immunomodulatory drug used as a preventive measure in healthy dogs. However, no studies have been published in healthy Leishmania infantum-seropositive dogs. The aim of this study was to evaluate the clinical efficacy and safety of domperidone as immunotherapy in Leishmania-seropositive healthy dogs.

METHODS

Sixty-seven dogs were treated with domperidone at 0.5 mg/kg and 44 dogs received placebo, once daily for 4 consecutive weeks. Monthly treatments were repeated every 4 months until the end of the 1-year follow-up period. Veterinary examinations were performed on days 0, 30, 120, 150, 240, 270 and 360. Samples of blood and urine were collected on days 0, 120, 240 and 360 for routine laboratory tests and quantitative in-house ELISA for the detection of L. infantum-specific antibodies. Furthermore, Leishmania real-time PCR and IFN-γ ELISA were performed at day 0 and the end of the study. Dogs that developed disease were withdrawn from the study and classified as sick dogs. Adverse drug reactions were reported.

RESULTS

Thirty dogs developed disease during the follow-up period: 13/67 (19.4%) in the group treated with domperidone and 17/44 (38.6%) in the placebo-treated group (P = 0.03). Low-seropositive dogs treated with domperidone (4/40, 9.1%) were significantly less likely to develop disease compared to low-seropositive dogs treated with placebo (7/24, 29.2%; P = 0.04), while no differences were found between domperidone (9/23, 39.1%) and placebo (10/20, 50%) in medium- to high-seropositive dogs. At the end of the study, a higher proportion of Leishmania PCR-positive dogs was observed in the placebo-treated group (16/33, 48.5%) compared to the domperidone group (13/51, 25.5%; P = 0.04). Furthermore, low-seropositive dogs treated with domperidone with an increase of IFN-γ concentration presented a higher increase than those treated with placebo at the end of the study. Four dogs treated with domperidone presented self-limiting diarrhea.

CONCLUSIONS

Healthy dogs with low L. infantum antibody levels treated with domperidone were less likely to develop disease compared to placebo-treated dogs. Furthermore, domperidone presented a good safety profile.

Elucidating the role played by bone marrow in visceral leishmaniasis

Leishmaniasis is a widespread group of infectious diseases that significantly impact global health. Despite high prevalence, leishmaniasis often receives inadequate attention in the prioritization of measures targeting tropical diseases. The causative agents of leishmaniasis are protozoan parasites of the Leishmania genus, which give rise to a diverse range of clinical manifestations, including cutaneous and visceral forms. Visceral leishmaniasis (VL), the most severe form, can be life-threatening if left untreated. Parasites can spread systemically within the body, infecting a range of organs, such as the liver, spleen, bone marrow and lymph nodes. Natural reservoirs for these protozoa include rodents, dogs, foxes, jackals, and wolves, with dogs serving as the primary urban reservoir for Leishmania infantum. Dogs exhibit clinical and pathological similarities to human VL and are valuable models for studying disease progression. Both human and canine VL provoke clinical symptoms, such as organ enlargement, fever, weight loss and abnormal gamma globulin levels. Hematologic abnormalities have also been observed, including anemia, leukopenia with lymphocytosis, neutropenia, and thrombocytopenia. Studies in dogs have linked these hematologic changes in peripheral blood to alterations in the bone marrow. Mouse models of VL have also contributed significantly to our understanding of the mechanisms underlying these hematologic and bone marrow abnormalities. This review consolidates information on hematological and immunological changes in the bone marrow of humans, dogs, and mice infected with Leishmania species causing VL. It includes findings on the role of bone marrow as a source of parasite persistence in internal organs and VL development. Highlighting gaps in current knowledge, the review emphasizes the need for future research to enhance our understanding of VL and identify potential targets for novel diagnostic and therapeutic approaches.

Serological survey of Leishmania infantum in apparently healthy dogs in different areas of Spain

BACKGROUND

Canine leishmaniosis caused by Leishmania infantum is an endemic disease in Spain. The dog is considered the main reservoir, and the detection of specific serum antibodies against L. infantum antigen is the most used technique for diagnosing this infection. The LEISCAN LEISHMANIA ELISA test is a commercialized enzyme-linked immunosorbent assay for the detection and measurement of canine anti-Leishmania serum antibodies.

OBJECTIVES

The aim of this study was to assess seroprevalence results of apparently healthy dogs in different areas of Spain using LEISCAN.

METHODS

Collection of sera from 5451 apparently healthy dogs was performed between 2020 and 2021 in different areas of Spain. Dogs were of adult age (≥12 months), were not previously diagnosed with clinical leishmaniosis or vaccinated against Leishmania and did not present clinical signs compatible with L. infantum infection. LEISCAN was performed following the manufacturer's protocol.

RESULTS

The overall seroprevalence was 5.5%. The highest seroprevalences were found in the Southeast of Spain: Comunidad Valenciana (14%) and Región de Murcia (14%), whereas the lowest seroprevalences were found in Northern Spain: Galicia (1%), Navarra (2%) and Castilla y León (2%) (p-value <0.001).

CONCLUSIONS

In conclusion, the seroprevalence for L. infantum in apparently healthy dogs in Spain varied from almost no infection to being over 10%.

Proteomic research on new urinary biomarkers of renal disease in canine leishmaniosis: Survival and monitoring response to treatment

The objective of our study was to search for survival biomarkers (SB) and treatment response monitoring biomarkers (TRMB) in the urinary proteome of dogs with renal disease secondary to canine leishmaniosis (CanL), using UHPLC-MS/MS. The proteomic data are available via ProteomeXchange with identifier PXD042578. Initially, a group of 12 dogs was evaluated and divided into survivors (SG; n = 6) and nonsurvivors (NSG; n = 6). A total of 972 proteins were obtained from the evaluated samples. Then, bioinformatic analysis reduced them to 6 proteins like potential SB increased in the NSG, specifically, Haemoglobin subunit Alpha 1, Complement Factor I, Complement C5, Fibrinogen beta chain (fragment), Peptidase S1 domain-containing protein, and Fibrinogen gamma chain. Afterwards, SG was used to search for TRMB, studying their urine at 0, 30, and 90 days, and 9 proteins that decreased after treatment were obtained: Apolipoprotein E, Cathepsin B, Cystatin B, Cystatin-C-like, Lysozyme, Monocyte differentiation CD14, Pancreatitis-associated precursor protein, Profilin, and Protein FAM3C. Finally, enrichment analysis provided information about the biological mechanisms in which these proteins are involved. In conclusion, this study provides 15 new candidate urinary biomarkers and an improved understanding of the pathogenesis of kidney disease in CanL.

Clinical presentation, diagnostic investigations, treatment protocols and outcomes of dogs diagnosed with tick-borne diseases living in the United Kingdom: 76 cases (2005-2019)

OBJECTIVES

To report the presence of tick-borne diseases in dogs living in the United Kingdom.

MATERIALS AND METHODS

Dogs with a final diagnosis of tick-borne diseases made between January 2005 and August 2019 at seven referral institutions in the United Kingdom were included in the study.

RESULTS

Seventy-six dogs were included: 25 were diagnosed with ehrlichiosis, 23 with babesiosis, eight with Lyme borreliosis and six with anaplasmosis. Fourteen dogs had co-infections with two or three pathogens. Except for those dogs with anaplasmosis and Lyme borreliosis, most dogs with tick-borne diseases had a history of travel to or from endemic countries. However, three dogs with ehrlichiosis, and one dog each infected with Babesia canis and Babesia vulpes did not have any history of travel. A variety of non-specific clinical signs and laboratory abnormalities were reported. Targeted treatment was successful at achieving clinical remission in 64 (84%) dogs.

CLINICAL SIGNIFICANCE

Even in non-endemic areas, veterinary surgeons should consider tick-borne diseases in dogs with compatible clinical presentation and laboratory findings and especially where there is a history of travel. As autochthonous transmission of tick-borne-pathogens does occur, an absence of travel should not rule out tick-borne diseases. Specific diagnostic testing is required to confirm infection, and this enables prompt targeted treatment and often a positive outcome.

Signalment, Immunological and Parasitological Status and Clinicopathological Findings of Leishmania-Seropositive Apparently Healthy Dogs

Canine leishmaniosis caused by Leishmania infantum is a disease with a wide range of clinical manifestations. Epidemiological serosurveys performed in Europe often lack a thorough assessment of clinical health status of studied dogs. The aim of this study was to evaluate signalment, immunological and parasitological status and clinicopathological findings of L. infantum-seropositive apparently healthy dogs (n = 212) living in endemic areas. Routine laboratory tests, endpoint in-house ELISA to quantify the anti-Leishmania antibodies, blood Leishmania qPCR and IFN-γ ELISA were performed. All dogs enrolled were L. infantum-seropositive and were classified as healthy (n = 105) or sick (n = 107) according to LeishVet guidelines. The sick group presented a higher proportion of medium to high antibody levels and positive qPCR and lower IFN-γ concentration compared to the healthy group. Sick dogs were mostly classified in LeishVet stage IIa. Biochemical alterations (98%) were the most common clinicopathological findings, with fewer urinary tract (46%) and hematological (40%) alterations. Apparently healthy L. infantum-seropositive dogs can be classified between truly healthy dogs and sick dogs with clinicopathological findings. Sick dogs presented medium to high seropositivity and parasitemia and low IFN-γ concentrations, and their most common clinicopathological abnormalities were serum protein alterations followed by proteinuria and lymphopenia.

Urinary cystatin C and N-acetyl-beta-D-glucosaminidase (NAG) as early biomarkers for renal disease in dogs with leishmaniosis

Canine leishmaniasis (CanL) is a disease caused by Leishmania infantum that can vary from a subclinical infection to a severe disease. Dogs affected with CanL present varying degrees of renal dysfunction. Unfortunately, traditional biomarkers such as urea and creatinine detect renal damage in advanced stages of the disease, so more accurate biomarkers are needed. Hence, we aimed to study how urinary cystatin C (CysC) and N-acetyl-beta-D-glucosaminidase (NAG), behave in dogs with CanL at different stages of the disease. Eighty-six CanL infected dogs were classified according to LeishVet stages: LI (16 dogs), LIIa (12 dogs), LIIb (12 dogs), LIII (16 dogs) and LIV (30 dogs); as a control, 17 healthy dogs were studied. Blood samples were collected for complete haematological and biochemistry analysis including plasma cystatin C. Urine analysis included urine specific gravity (USG), urine protein to creatinine ratio (UPC), CysC and NAG expressed as a ratio with creatinine uCysCc (μg/g) and uNAGc (IU/g). The haematological, biochemical and urinary analysis coincided with the LeishVet guidelines. The statistical study of the uCysCc ratio and the uNAGc, showed significant increase when compared against control starting from group LI (p < 0.05). Interestingly, when the cut-off values were calculated using the ROC curve, uCysCc (258.85 µg/g) and uNAGc (2.25 IU/g) 75 % of the dogs included in LI groups surpassed the threshold. Hence our study indicates that uCysCc and uNAGc, could help to detect early renal damage in CanL affected dogs.

Exposure to and infection by Leishmania infantum among domestic dogs in an area of the Cerrado biome, Maranhão, Brazil

Visceral Leishmaniasis is a serious public health problem and dogs are considered to be the main source of infection in urban areas. In Brazil, this disease is present in all regions, but with high concentration of cases in the Northeast, and the state of Maranhão is considered to be an endemic region. The aim of this study was to conduct an epidemiological, spatial, molecular and serological survey on Leishmania infantum among domestic dogs in the municipality of Belágua, Maranhão. Blood samples were collected from dogs and questionnaires were applied to their owners to obtain epidemiological data and risk factors relating to this zoonosis in the region. The coordinates of the dogs' homes were obtained to produce a disease risk map. Serological diagnoses were made using the indirect immunofluorescence reaction (IFAT) and the dual-path platform chromatographic immunoassay test (DPP®) (Bio-Manguinhos/FIOCRUZ, Brazil). A molecular investigation was undertaken using the polymerase chain reaction (PCR). Georeferencing was performed using the global positioning system (GPS) and cases of canine visceral leishmaniasis in the municipality were spatially represented and analyzed using QGIS version 3.16.6 (QGIS Development Team, 2021). A total of 205 blood samples were collected, of which 122 (59.51%) were seroreactive for L. infantum through IFAT, while the DPP test showed 84 reactive samples (40.97%). IFAT and DPP detected 16 positive animals simultaneously. One sample that was seroreactive through IFAT was also positive through PCR. In the clinical evaluation, it was observed that among the seropositive dogs, 112 (91.80%) were symptomatic and 10 (8.20%) were asymptomatic. In the spatial analysis, the Kernel density estimator enabled determination of the place at greatest risk of occurrence of the disease. The areas with the highest concentrations of cases were in districts with large quantities of precarious housing and lack of basic sanitation. This was the first report on the occurrence of L. infantum among dogs in the municipality of Belágua. The results show that canine visceral leishmaniasis is well dispersed in this municipality, thus putting at risk the human population.

Arginine, symmetric and asymmetric dimethylarginine levels in canine leishmaniasis

The study aimed to investigate the levels of arginine, symmetric dimethylarginine (SDMA), and asymmetric dimethylarginine (ADMA) in dogs with canine leishmaniasis (CanL) and their relationship with some renal and cardiovascular parameters. A total of 60 dogs were enrolled, including 40 with CanL and 20 healthy controls. The CanL group was divided into four stages based on clinical and laboratory findings. The levels of plasma arginine, SDMA, and ADMA were determined by high performance liquid chromatography (HPLC). The data from the healthy group were compared with those from the CanL group, and according to the stages. In dogs with CanL, systolic and diastolic blood pressure, plasma creatinine, cystatin-C, phosphorus, potassium, and low-density lipoprotein concentrations, the urine protein/creatinine ratio, the amount of nitric oxide, and creatine kinase-MB activity were higher, while the high-density lipoprotein concentration was lower compared to healthy controls. The concentration of arginine was low (p < 0.05) and the levels of ADMA (p < 0.001) and SDMA (p < 0.05) were high in dogs with CanL. There were no statistically significant differences in arginine concentration among the different stages of CanL. However, the concentration of plasma ADMA was higher in all stages of CanL compared to the healthy group, and the concentration of plasma SDMA was higher in Stage IV compared to the healthy group and Stage III. The present study demonstrates for the first time a decrease in arginine concentration and an increase in ADMA concentration in dogs with CanL. The increase in SDMA concentration in dogs with CanL was consistent with previous studies. However, compared to other renal parameters, SDMA exhibited limited performance distinguishing between clinical stages of CanL. These findings could be a source for future diagnostic and therapeutic studies to explain the renal and cardiovascular pathophysiology of CanL. Additional clinical studies that include treatment and patient follow-up with an assessment of the acute phase response are needed to provide a more detailed understanding of the changes observed in dogs with CanL.

Characterization and Proteomic Analysis of Plasma EVs Recovered from Healthy and Diseased Dogs with Canine Leishmaniosis

Dogs are highly valued companions and work animals that are susceptible to many life-threatening conditions such as canine leishmaniosis (CanL). Plasma-derived extracellular vesicles (EVs), exploited extensively in biomarker discovery, constitute a mostly untapped resource in veterinary sciences. Thus, the definition of proteins associated with plasma EVs recovered from healthy and diseased dogs with a relevant pathogen would be important for biomarker development. For this, we recovered, using size-exclusion chromatography (SEC), EVs from 19 healthy and 20 CanL dogs’ plasma and performed proteomic analysis by LC-MS/MS to define their core proteomic composition and search for CanL-associated alterations. EVs-specific markers were identified in all preparations and also non-EVs proteins. Some EVs markers such as CD82 were specific to the healthy animals, while others, such as the Integrin beta 3 were identified in most samples. The EVs-enriched preparations allowed the identification of 529 canine proteins that were identified in both groups, while 465 and 154 were only identified in healthy or CanL samples, respectively. A GO enrichment analysis revealed few CanL-specific terms. Leishmania spp. protein identifications were also found, although with only one unique peptide. Ultimately, CanL-associated proteins of interest were identified and a core proteome was revealed that will be available for intra- and inter-species comparisons.

First study on microscopic and molecular detection of Acanthocheilonema reconditum and Leishmania infantum coinfection in dogs in Southwest Colombia

Background and Aim

Canine vector-borne diseases represent an important issue for the welfare and health of animals, but also have great zoonotic potential. These diseases are caused by bacteria, nematodes such as filariae, and other parasites such as Leishmania spp. Given the difficulty in differentiating common microfilariae in dogs by microscopy and serological methods, molecular techniques such as polymerase chain reaction (PCR) and sequencing should be valuable for reaching a reliable diagnosis. This study aimed to use microscopy and PCR to identify the microfilarial species in dogs from Valle del Cauca, Colombia, and a possible association with Leishmania infantum parasites.

Materials and Methods

This study was conducted on 270 dogs from Pradera and Florida municipalities. Microfilariae were detected in dogs by optical microscopy and amplification with 5.8S-ITS2-28S. Species identification was achieved through the amplification of the gene cytochrome oxidase I (COX1).

Results

Microscopic detection of microfilariae was possible in 4.81% (13/270) of the dogs. In addition, by PCR of COX1 and Sanger sequencing of ITS2, Acanthocheilonema reconditum was identified as the circulating microfilarial species in 12 dogs, coinfecting with the species L. infantum (Leishmania donovani complex).

Conclusion

To the best of our knowledge, this is the first report on A. reconditum and L. infantum mixed infection in dogs in Colombia, particularly in the Valle del Cauca.

Detecting Leishmania in dogs: A hierarchical-modeling approach to investigate the performance of parasitological and qPCR-based diagnostic procedures

BACKGROUND

Domestic dogs are primary reservoir hosts of Leishmania infantum, the agent of visceral leishmaniasis. Detecting dog infections is central to epidemiological inference, disease prevention, and veterinary practice. Error-free diagnostic procedures, however, are lacking, and the performance of those available is difficult to measure in the absence of fail-safe "reference standards". Here, we illustrate how a hierarchical-modeling approach can be used to formally account for false-negative and false-positive results when investigating the process of Leishmania detection in dogs.

METHODS/FINDINGS

We studied 294 field-sampled dogs of unknown infection status from a Leishmania-endemic region. We ran 350 parasitological tests (bone-marrow microscopy and culture) and 1,016 qPCR assays (blood, bone-marrow, and eye-swab samples with amplifiable DNA). Using replicate test results and site-occupancy models, we estimated (a) clinical sensitivity for each diagnostic procedure and (b) clinical specificity for qPCRs; parasitological tests were assumed 100% specific. Initial modeling revealed qPCR specificity < 94%; we tracked the source of this unexpected result to some qPCR plates having subtle signs of possible contamination. Using multi-model inference, we formally accounted for suspected plate contamination and estimated qPCR sensitivity at 49-53% across sample types and dog clinical conditions; qPCR specificity was high (95-96%), but fell to 81-82% for assays run in plates with suspected contamination. The sensitivity of parasitological procedures was low (~12-13%), but increased to ~33% (with substantial uncertainty) for bone-marrow culture in seriously-diseased dogs. Leishmania-infection frequency estimates (~49-50% across clinical conditions) were lower than observed (~60%).

CONCLUSIONS

We provide statistical estimates of key performance parameters for five diagnostic procedures used to detect Leishmania in dogs. Low clinical sensitivies likely reflect the absence of Leishmania parasites/DNA in perhaps ~50-70% of samples drawn from infected dogs. Although qPCR performance was similar across sample types, non-invasive eye-swabs were overall less likely to contain amplifiable DNA. Finally, modeling was instrumental to discovering (and formally accounting for) possible qPCR-plate contamination; even with stringent negative/blank-control scoring, ~4-5% of positive qPCRs were most likely false-positives. This work shows, in sum, how hierarchical site-occupancy models can sharpen our understanding of the problem of diagnosing host infections with hard-to-detect pathogens including Leishmania.

Ein Update zur Leishmaniose des Hundes: Diagnostik, Therapie und Monitoring

Aufgrund von steigenden Importzahlen von Hunden aus dem Ausland, zunehmendem Reiseverkehr sowie den Veränderungen klimatischer Bedingungen in Europa gewinnen Infektionen mit Leishmania (L.) infantum bei Hunden in Deutschland zunehmend an Bedeutung. Daher sollten auch Hunde aus dem Ausland, die keine klinischen Symptome zeigen, direkt nach Import sowie erneut 6 Monate später auf vektorübertragene Infektionserreger getestet werden. Bei Hunden mit klinischer Symptomatik, die hinweisend auf eine Leishmaniose sind, werden direkte und indirekte Nachweisverfahren sowie eine hämatologische und biochemische Untersuchung unter Einbezug von Serumeiweißelektrophorese sowie Bestimmung des C-reaktiven Proteins empfohlen. Als Leitfaden für die Therapie sowie das Monitoring stehen die LeishVet-Guidelines zur Verfügung. Es stehen leishmanizide und leishmaniostatische Wirkstoffe zur Verfügung, die in first-line, second-line und third-line unterschieden werden. Zur Anpassung der Allopurinol-Dosierung wird der Stufenplan empfohlen. Aufgrund der Veränderung der klimatischen Bedingungen kommt es zu einer Ausbreitung der Habitate von Sandmücken, die als Vektoren der Leishmaniose bekannt sind. Als weitere Infektionsquellen sind Deckakte, transplazentare Infektionen, Bisswunden und Bluttransfusionen beschrieben. Leishmania infantum hat zoonotisches Potential und ist daher auch in Hinblick auf den „One-Health“-Gedanken bedeutend.

Urinary phoretograms performed by capillary electrophoresis in dogs with chronic disease with or without Leishmania infantum infection

INTRODUCTION

The study of early markers to detect kidney malfunction has increased in recent years since serum markers, such as creatinine increase when there is a 75% loss of renal mass. Urinary capillary electrophoresis (UCE) is an available laboratory technique that provides an easily interpretable electrophoretic pattern. This pattern in our study has been divided into five fractions as it is done in serum: fraction 1 migrating in the albumin zone, fraction 2 in the alpha₁-globulins zone, fraction 3 in the alpha₂-globulins zone, fraction 4 in the beta-globulins zone, and fraction 5 in the gamma globulins zone. UCE can be useful in the early diagnosis of renal disease.

MATERIAL AND METHODS

In this study, UCE was performed in dogs with azotemia and proteinuria due to chronic kidney disease (CKD) not related to Leishmania infantum (L. infantum) infection (G₁, n = 11) and dogs with CKD related to L. infantum infection (G₂, n = 17) and compared with reference intervals from healthy dogs (G₀, n = 123), with the aim of comparing their phoretograms and assessing changes in the fractions of the phoretograms based on the health status of individuals.

RESULTS

Fraction 2 was statistically augmented in dogs with CKD (G₁) when compared with the healthy population (G₀) and dogs infected by L. infantum (G₂). Fraction 3 was statistically increased in dogs with CKD (G₁) and dogs infected by L. infantum (G₂) compared with G_0. Fraction 4 was found to be statistically decreased in dogs with CKD (G₁) and dogs infected by L. infantum (G₂) compared with G_0. Fraction 5 was statistically higher in dogs with L. infantum (G₂) compared with G₀ and dogs with CKD (G₁). No statistical relationship was found between the protein to creatinine ratio and different fractions from the urinary phoretogram in the study population. No statistical relationship was found between serum and urine fractions in the study population.

DISCUSSION

The results of the present study suggest that UCE is a promising non-invasive technique that might be used as a part of the diagnostic and follow-up in dogs with kidney disease due to different pathologies.

First Report of Autochthonous Canine Leishmaniasis in Hong Kong

Canine leishmaniasis is a zoonotic disease caused by Leishmania infantum; transmitted by the bite of phlebotomine sand flies. Leishmania infantum amastigotes were identified by cytology from a locally born Hong Kong dog exhibiting nasal, cutaneous, and systemic disease who was part of a kennel of eight dogs. All eight kennel dogs were subsequently tested serologically by enzyme-linked immunosorbent assay (ELISA) and by polymerase chain reaction (PCR) followed by DNA sequencing for L. infantum infection. The local dog was seropositive and blood and splenic tissue were PCR positive for L. infantum whilst the other kennel dogs were negative on serology and PCR. Autochthonous transmission was suspected for the local dog as Hong Kong lacks known vectors of L. infantum. Either vertical transmission from the deceased dam who had previously died with disease suspicious for leishmaniasis or horizontal transmission from a second non-locally born kennel dog who had been diagnosed previously with leishmaniasis was possible. This is the first recorded autochthonous case of canine leishmaniasis in Hong Kong. Leishmaniasis should be considered as a differential for cutaneous or systemic illness in local untraveled dogs in Hong Kong. In addition, as dogs serve as L. infantum reservoirs for human infection attention should be paid to the possibility of leishmaniasis emerging in Hong Kong.

Canine Leishmaniasis: Update on Epidemiology, Diagnosis, Treatment, and Prevention

Dog are the main reservoir of Leishmania infantum, causing canine leishmaniasis, an incurable multisystemic disease that leads to death in symptomatic dogs, when not treated. This parasite causes visceral, cutaneous, and mucosal leishmaniasis in people in the Mediterranean Basin, North Africa, South America, and West Asia. This disease is mostly unknown by veterinarians outside the endemic areas, but the disease is expanding in the Northern Hemisphere due to travel and climate change. New methodologies to study the epidemiology of the disease have found new hosts of leishmaniasis and drawn a completely new picture of the parasite biological cycle. Canine leishmaniasis diagnosis has evolved over the years through the analysis of new samples using novel molecular techniques. Given the neglected nature of leishmaniasis, progress in drug discovery is slow, and the few drugs that reach clinical stages in humans are unlikely to be commercialised for dogs, but several approaches have been developed to support chemotherapy. New-generation vaccines developed during the last decade are now widely used, along with novel prevention strategies. The implications of the epidemiology, diagnosis, treatment, and prevention of canine leishmaniasis are fundamental to public health.

Gut Microbiota and Lymphocyte Subsets in Canine Leishmaniasis

Gut microbiota seems to interact with immune system. Canine leishmaniasis pathogenesis and severity of disease lean on the host immunity, but there is no information in literature about gut microbiota in infected animals. Thus, this study aims to compare the microbiota composition and leukocyte subset of healthy dogs with those of asymptomatic dogs exposed to Leishmania spp. and dogs with clinical leishmaniasis. Thirty-nine dogs were enrolled and grouped into three groups: healthy, exposed asymptomatic and infected symptomatic for Leishmania spp. Flow cytometry on whole blood evaluated the prevalence of CD4, CD5, CD8, CD11b, CD14, and CD21 positive cells. Gut microbiota was investigated using a next generation sequencing (NGS) technique. Firmicutes resulted significantly more abundant in the healthy dogs compared with the other two groups. Conversely, Proteobacteria were more abundant in symptomatic dogs. Even in rarest phyla comparison some significant differences were found, as well as in comparison at classes, order, family and genus levels. The symptomatic group had lower concentration of all the lymphocyte classes (CD5, CD21, CD4, CD8) compared to the other groups. A lower abundance of Firmicutes is reported in literature in diseased animals compared to the healthy ones and this is in agreement with the results of this study. Increased Proteobacteria in sick animals could suggest a dysbiosis status, even without distinct gastrointestinal signs. The leukocyte classes results indicate a decreased Th1 response in symptomatic dogs. Studies also investigating the cytokine response could deepen the knowledge on the pathogenesis of canine leishmaniasis.

Review and statistical analysis of clinical management of feline leishmaniosis caused by Leishmania infantum

Background

There is limited information about feline leishmaniosis (FeL) management in clinical practice. Leishmania infantum is the species of Leishmania most frequently reported in both dogs and cats in countries of the Mediterranean region (henceforth ‘Mediterranean countries’), Central and South America, and Iran. This study was conducted to provide veterinary clinicians with an updated overview of evidence-based information on leishmaniosis in cats.

Methods

A review was performed using PubMed, Science Direct, Google Scholar and Web of Science. Case reports of FeL caused by L. infantum were sought for the period 1912 to 1 June 2021.

Results

Sixty-three case reports are included in this review. Fifty-nine out of the 63 cats were from Europe, mostly from Mediterranean countries (88.9%). Most of them were domestic short-haired cats (90%) with a mean age of 7.9 years, and had access to the outdoors (77.3%). Sixty-six percent of the cats had comorbidities, of which feline immunodeficiency virus infection was the most frequent (37.7%). Dermatological lesions (69.8%) was the most frequent clinical sign, and hyperproteinemia (46.3%) the most frequent clinicopathological abnormality. Serology was the most performed diagnostic method (76.2%) and was positive for 93.7% of cats. Medical treatment was applied in 71.4% of cats, and allopurinol was the most used drug (74.4%). Survival time was greater for treated cats (520 days; 71.4% of cats) than non-treated cats (210 days; 25.4%).

Conclusions

The majority of the cats had comorbidities, of which feline immunodeficiency virus was the most frequent. Dermatological lesions were frequently reported, and systemic clinical signs and clinicopathological abnormalities were also common. Serology may be useful for the diagnosis of FeL in clinical practice, and a positive titer of ≥ 1/40 may be a useful cut-off for sick cats. The reported treatments and dosages varied, but there was a good clinical response and longer survival in most of the cats treated with allopurinol monotherapy.

Graphical abstract

Leishmania exposure in dogs from two endemic countries from New and Old Worlds (Brazil and Portugal): evaluation of three serological tests using Bayesian Latent Class Models

BACKGROUND

Zoonotic leishmaniosis caused by Leishmania infantum is endemic in several countries of the Mediterranean Basin, Latin America, and Asia. Dogs are the main hosts and reservoirs of human infection. Thus, from a One Health perspective, early diagnosis of Leishmania infection in dogs is essential to control the dissemination of the parasite among other dogs and to humans. The aim of this study was to estimate the diagnosis accuracy of three serological tests to detect antibodies to Leishmania in dogs from two endemic settings using Bayesian latent class models (BLCM).

METHODS

A total of 378 dogs from two Portuguese and Brazilian endemic areas of leishmaniosis (194 animals from Portugal and 184 from Brazil) were screened. Detection of anti-Leishmania antibodies was performed using two commercial ELISA (L. infantum IgG-ELISA® and EIE-LVC®) and a rapid immunochromatographic test (DPP-LVC®). Bayesian latent class models were used to estimate Leishmania infection prevalence, together with sensitivities and specificities of the three diagnostic tests, in the two dog populations simultaneously. Predictive values were also calculated. Credibility intervals (CI) were obtained, considering different types of prior information.

RESULTS

A posterior median Leishmania seroprevalence of 13.4% (95% CI 9.0-18.7) and of 21.6% (15.0-28.3) was estimated to the Portuguese and Brazilian dog subpopulations, respectively. The Bayesian analysis indicated that all tests were highly specific (specificity above 90%), and that the DPP-LVC® was more sensitive (96.6%; 83.1-99.9) than both ELISAs in the Portuguese subpopulation, while in the Brazilian subpopulation, EIE-LVC® and L. infantum IgG-ELISA®, had the highest sensitivity (88.2%; 73.7-97.0) and specificity (98.7%; 95.1-99.9), respectively.

CONCLUSIONS

In general, the levels of diagnosis accuracy of the three serological tests to detect Leishmania antibodies assessed by BLCM indicate their utility in canine epidemiological studies. The same approach should be used to assess the performance of these techniques in the clinical management of infected and sick dogs using representative samples from the wide spectrum of clinical situations, namely from subclinical infection to manifest disease. The low positive predictive value of the serological tests used in the current protocol of the Brazilian Ministry of Health suggests that they should not be used individually and may not be sufficient to target reservoir-based control interventions.

Molecular and serological evaluation of visceral leishmaniasis in domestic dogs and cats in Maragheh County, north-west of Iran, 2018-2021

Objective

Zoonotic visceral leishmaniasis (VL) is caused by Leishmania infantum, of which dogs are the main reservoir. VL is endemic in the Middle East, also in some parts of Iran. Following reports of new cases of VL in children in Maragheh County, the non‐endemic area of the disease, we encouraged to conduct a preliminary study on domestic dogs and cats to identify their potential role as reservoirs for the disease.

Materials and Methods

This study was conducted during a period of 3 years from 2018 to 2021. Two hundred ownership dogs and 25 cats from Maragheh County, north‐west of Iran, were randomly screened. Blood samples were collected. A direct agglutination test (DAT) was used for the detection of anti‐L. infantum antibodies. Furthermore, buffy coat samples from the L. infantum seropositive animals were examined to detect parasite presence using polymerase chain reaction.

Results

Out of the total of 200 ownership dogs evaluated, 170 (85%) were male and 30 (15%) were female with a mean age of 4.3 years. Anti‐L. infantum antibodies (IgG cut‐off ≥ 1:320) were observed in 3.5% of dogs (7/200) by the DAT test. All seropositive dogs were identified in the first year of examination. Regarding molecular approaches in seropositive dogs, two samples were positive for a 565 bp kDNA minicircle gene specific for L. infantum. During the study period, no seropositive case was detected in the cats examined.

Conclusions

This study shows that the domestic cycle of L. infantum has been established in the studied region. It is necessary to increase the awareness and monitoring of the disease with the study of wild reservoirs periodically.