Canine Monocytic Ehrlichiosis Research Articles

Prevalence, risk factors, and hematologic changes in dogs from Baja California with presence of Ehrlichia spp., and coinfection with Anaplasma spp.

Ehrlichia and Anaplasma are obligate intracellular, gram-negative bacteria with tropism for hematopoietic cells, especially leukocytes and platelets. There are several Ehrlichia species that infect dogs. Ehrlichia canis is transmitted by Rhipicephalus sanguineus and replicates within monocytes and macrophages, leading to canine monocytic ehrlichiosis, a disease of worldwide distribution. The clinical signs are varied and non-specific. Anaplasma has two species that infect dogs, Anaplasma phagocytophilum and Anaplasma platys, the second also transmitted by Rhipicephalus sanguineus. This study aimed to evaluate the epidemiology and hematologic changes associated with the presence of Ehrlichia spp. and Anaplasma spp. coinfection in dogs from Baja California. Complete hematological analysis, examination of buffy coat smears, and ELISA tests were performed on blood samples from three veterinary diagnostic laboratories from Mexicali and Tijuana cities in Baja California, Mexico. A total of 5,469 dog samples were analyzed. The overall prevalence of Ehrlichia spp., was 4.79%, with a distribution of 6.3% in Mexicali (OR: 2.39 CI: 1.69-3.17) and 2.5% in Tijuana. The peak of infection was found in September. Contact with other dogs and tick infestation were the risk factors associated with infection (P < 0.05). There was 96% co-infection only in Tijuana and 0% in Mexicali. Anemia, thrombocytopenia, and hyperproteinemia are associated with Ehrlichia spp., and Ehrlichia/Anaplasma infection. In view of the foregoing, we have to maintain epidemiologic vigilance, as well as look further into the ticks present in the state and the possibility of transmission of unusual pathogens.

Evaluating the circulation of Ehrlichia canis and Rickettsia spp. in domestic dogs from a semiarid region in Brazil

Tick-borne diseases are important for animal and human health, because they can cause death if not diagnosed and treated early. Canine monocytic ehrlichiosis (CME) can cause high morbidity in dog populations. Rocky Mountain Spotted Fever (RMSF) is among the most virulent infectious in humans; dogs are also susceptible to infection. The aims of this study were to evaluate the presence of Ehrlichia canis and Rickettsia spp. infections in domestic dogs, and to identify tick species parasitizing dogs among urban areas of two municipalities (Sobral and Alcântaras) in the Ceará State, Northeastern Brazil. A total of 208 domiciled dogs was sampled. After clinical evaluation, blood samples and ticks were collected and submitted to Real-Time Polymerase Chain Reaction (RT-PCR) targeting E. canis DNA. Serum samples were screened by Indirect Immunofluorescence Assays (IFA) for antibodies against different strains of Rickettsia spp. previously recognized in Brazil. The results of this study indicate the molecular detection of E. canis in the state of Ceará, Brazil, where the proportion of canine infection in Sobral (9.9%) was higher than in Alcântaras (5.6%). Rhipicephalus sanguineus sensu lato was the prevalent tick species infesting the dogs in both municipalities (43.5 and 53.3%, respectively). Our serological results indicate that dogs of the study area were at low risk of exposure to these tick-borne Rickettsia spp. of the spotted fever group. Our study offers epidemiological data of these diseases to better understanding Rickettsiales epidemic and enzootic cycles in the Brazilian semiarid region, improving prevention and control measures.

Assessment of the effect of long-term serum storage for retrospective serologic diagnosis of canine monocytic ehrlichiosis (Ehrlichia canis)

There is currently sparse information on the possible effect of long-term storage of serum specimens for the retrospective serodiagnosis of canine monocytic ehrlichiosis (CME). The aim of this study was to assess the agreement between the original serologic outcome and the results of a repeat indirect fluorescent antibody (IFA) assay for the detection of IgG antibodies against E. canis. A secondary aim was to compare the diagnostic performance of two commercially available point-of-care (POC) immunochromatographic (IC) assays. Archived serum samples originally tested as positive (n=66) or negative (n=19) for E. canis IgG antibodies and kept frozen at −20°C for a median of 22 years, were retrospectively examined by IFA and by two POC IC assays. Cohen’s Kappa coefficient (0.748, p < 0.0001), indicated a substantial agreement between the original and repeat serologic testing results. An almost identical high sensitivity and moderate specificity were established for the two POC IC assays. Canine serum specimens on long-term storage may still be of value for seroepidemiologic surveys investigating the exposure to E. canis.

The geographic limits and life history of the tropical brown dog tick, Rhipicephalus linnaei (Audouin, 1826), in Australia with notes on the spread of Ehrlichia canis

The tropical brown dog tick, Rhipicephalus linnaei, is a tick of much medical, veterinary, and zoonotic importance. This tick has a nearly world-wide distribution due to its ability to survive and propagate in kennels and houses. Rhipicephalus linnaei is the vector of Ehrlichia canis, the causative agent of canine monocytic ehrlichiosis, an often debilitating disease of canids and, occasionally, humans. To prevent incursion of E. canis into Australia, dogs entering Australia have been required to have a negative immunofluorescence antibody test for E. canis. In May 2020 however, E. canis was detected in Western Australia. The detection of E. canis in Australia prompted disease investigation and concerted surveillance for R. linnaei and E. canis in regions across Australia. These investigations revealed that R. linnaei was established far beyond the previously recognised geographic range limits of this tick. In the present paper, using records from various collections, published data, and data from our network of veterinarian collaborators and colleagues, we update the current geographic range of R. linnaei in Australia. Our analyses revealed that the geographic range of R. linnaei in Australia is much wider than was previously supposed, particularly in Western Australia, and in South Australia. We also map, for the first time, where E. canis has been detected in Australia. Last, we discuss the possible routes of incursion and subsequently the factors which may have aided the spread of E. canis in Australia which led to the establishment of this pathogen in Australia.

Clinico-diagnostic and Therapeutic Management of Ehrlichiosis in Dog

Background: The research work was undertaken to investigate the efficacy of various diagnostic tests by using conventional microscopic examination, rapid Ab detection test and molecular technique, haemato-biochemical changes, Abdominal organs changes using ultrasonography, and therapeutic efficacy of different treatment protocols on Canine Monocytic Ehrlichiosis (CME) infected dogs from in and around Navsari, Gujarat, India. Methods: 69 dogs suspected of ehrlichiosis based on clinical signs and hematological values and then subjected to blood and buffy coat smear examination, rapid Ab detection test and PCR based assay targeting 16S rRNA gene. The pre and post-treatment haematology and biochemical analysis of treatment groups along with all the positive dogs were performed. Further, all the treatment group dogs were subjected to ultrasound for evaluating organ abnormalities. Modified Clinical Sign Grading (MCSG) score for CME-infected dogs was carried out to evaluate therapeutic responses based on minimizing the clinical score. Descriptive statistics along with Student t-test and One-way analysis of variance (ANOVA) followed by DMRT was performed to compare differences between means wherever applicable. Result: CME incidence among the 69 suspected cases was 49.28%. Out of 69 suspected dogs, Ehrlichial inclusions or morulae in the monocytes could be identified in only 4.35% of blood smears and 10.14% of buffy coat smears examined by Giemsa and or Field-stained and 15.94% of dogs were found positive for Ehrlichia genus by PCR. 72.5 per cent of dogs were found positive for antibodies to E. canis, out of 40 dogs. The sensitivity of blood smear examination, buffy coat smear examination, and thrombocytopenia was 10.34%, 24.14% and 89.66%, respectively. The specificity of all the diagnostic tests was 100%. The anemia along with leucopenia, were the most significant hematological alteration recorded while ALP, creatinine, and BUN were elevated and albumin was significantly decreased in CME-infected dogs. Significant improvement of haemato-biochemical parameters towards normalcy in both treatment groups. However, a higher percentage of reduction was observed in the clinical score of imidocarb treated CME affected dogs than in the oxy-doxycycline therapy after 14 days.

Occurrence and hematological aspects of dogs with Canine Monocytic Ehrlichiosis

Canine monocytic ehrlichiosis (CME) is an infectious disease caused by a gram-negative bacterium of the genus Ehrlichia spp., a monocyte parasite that leads to thrombocytopenia, anemia, hyporexia, apathy, pale mucous membranes, among others. The etiological agent is distributed worldwide, but there is a greater incidence and considerable prevalence in places with temperate climates due to the high presence of the tick vector Rhipicephalus sanguineus. In Brazil, the number of cases of this disease appears to have increased in many regions, due to several factors, but more studies are still needed regarding the prevalence in various regions. In view of the aforementioned points, this retrospective study aimed to address the findings of the clinical and laboratory evaluation of 43 medical records with the definitive diagnosis of canine monocytic ehrlichiosis, in naturally infected dogs, treated at HOVET - UFES, during the period of June 2017 to September 2023, in order to discuss and relate the findings found with current literature, as well as report the occurrence of this disease. For this, we used the clinical and laboratory records of dogs that showed positivity in the SNAP 4Dx Plus® rapid test and/or in blood smears, and presented Ehrlichia spp. morulae. in leukocytes. Simultaneously, clinical data, blood count findings and biochemical test results were prepared in figures, tables and organizational charts. Subsequently, with the information and results found, descriptive analysis of the data was used to demonstrate the occurrence through percentages. The most frequent clinical and laboratory changes were the presence of ticks, hyporexia, lymphadenomgelia, apathy, pale mucous membranes, thrombocytopenia, normocytic normochromic anemia, lymphopenia and hypoalbuminemia. Therefore, it is concluded that it is essential to report the occurrence of Ehrlichia sp. in dogs, as well as knowing the main clinical and laboratory changes mentioned so that it is possible to assist in the early identification of canine monocytic ehrlichiosis.

Whole Genome Sequencing and Comparative Analysis of the First Ehrlichia canis Isolate in China.

Ehrlichia canis, a prominent tick-borne pathogen causing canine monocytic ehrlichiosis (CME), is one of the six recognized Ehrlichia species worldwide. Despite its widespread presence in ticks and host dogs in China, comprehensive genomic information about this pathogen remains limited. This study focuses on an in-depth analysis of E. canis YZ-1, isolated and cultured from an infected dog in China. The complete genome of E. canis YZ-1 was sequenced (1,314,789 bp, 1022 genes, 29% GC content, and 73% coding bases), systematically characterizing its genomic elements and functions. Comparative analysis with representative genomes of Ehrlichia species, including E. canis strain Jake, E. chaffeensis, Ehrlichia spp., E. muris, E. ruminantium, and E. minasensis, revealed conserved genes, indicating potential evolutionary connections with E. ruminantium. The observed reduction in virulence-associated genes, coupled with a type IV secretion system (T4SS), suggests an intricate balance between pathogenicity and host adaptation. The close relationship with E. canis Jake and E. chaffeensis, alongside nuanced genomic variations with E. ruminantium and E. mineirensis, underscores the need to explore emerging strains and advancements in sequencing technologies continuously. This genetic insight opens avenues for innovative medications, studies on probiotic resistance, development of new detection markers, and progress in vaccine development for ehrlichiosis. Further investigations into the functional significance of identified genes and their role in host-pathogen interactions will contribute to a more holistic comprehension of Ehrlichia's biology and its implications for pathogenicity and transmission.

What's Eating You? Rhipicephalus Ticks Revisited.

Rhipicephalus ticks are vectors of disease in humans and animals. Rhipicephalus sanguineus sensu lato (the brown dog tick) is one of the most geographically widespread tick species worldwide, likely due to its ability to colonize human and canine dwellings over a range of habitats. They transmit a variety of diseases to dogs and humans, including canine babesiosis, canine monocytic ehrlichiosis, hepatozoonosis, Mediterranean spotted fever, and Rocky Mountain spotted fever. Tick bites manifest as intensely pruritic, erythematous papules at the site of tick attachment; symptomatic relief usually can be achieved with topical antipruritics. Prevention of tick bites is best achieved through a combination of veterinary and environmental control; protective clothing; repellents, such as N,N-diethyl-meta-toluamide (DEET) and permethrin; and prompt identification and removal of ticks.

Studies on clinical and molecular diagnosis in naturally occuring cases of Canine Monocytic Ehrlichiosis

Studies on clinical and molecular diagnosis in naturally occuring cases of Canine Monocytic Ehrlichiosis

Novel renal injury markers in dogs with ehrlichiosis

Canine monocytic ehrlichiosis (CME) has been observed to impact renal function. Currently, the recognition of acute kidney injury is through the nonspecific biomarker serum creatinine (sCr). Novel markers of renal injury such as urinary clusterin (uClust) and urinary cystatin B (uCysB) may increase our understanding of the relationship between ehrlichiosis and renal cellular injury. The aim of this study was to evaluate novel renal injury biomarkers in dogs with acute CME. Twenty healthy dogs were enrolled in the control group (CG), and 16 dogs naturally infected with Ehrlichia canis were included in the Ehrlichia Group (EG). All dogs were followed for 45 days. EG dogs were treated with doxycycline twice daily for the first 30 days. Urine and serum were collected at: 0, 0.5, 1, 15, 30, and 45 days after start of treatment. Urine concentrations of uClust and uCysB were determined using a research ELISA immunoassay. A linear mixed model was used to estimate population mean of renal injury markers with patient as the random effect, and day and treatment as fixed effects. EG was observed to have higher uClust values compared to CG (estimated population mean EG: 213 ng/dL vs. CG: 84 ng/dL, P &lt; 0.001). EG was observed to have higher uCysB values compared to CG (estimated population mean EG: 248 ng/dL vs. CG: 38 ng/dL, P &lt; 0.001). Increases in uCysB and uClust suggest the presence of renal injury and a possible mechanism for the observed predisposition to chronic kidney disease in dogs with ehrlichiosis.

Misdiagnosis of canine monocytic ehrlichiosis: why do we still risk animal lives?

Canine Monocytic Ehrlichiosis (CME) is a tick-borne disease caused by Ehrlichia canis that manifests as acute, chronic, or subclinical forms without specific clinical symptoms. This disease is diagnosed using clinical and laboratory findings (blood smears, molecular techniques, and serology). This study aimed to demonstrate the occurrence of false-positive results for Ehrlichia spp. in veterinary clinical practice. Seventy dogs with positive blood smears before treatment for Ehrlichia spp. subjected to doxycycline and imidazole treatment were analyzed using hematological examination, polymerase chain reaction (PCR), and indirect immunofluorescence assay. PCR analysis identified no samples positive for E. canis according to PCR analysis, while serological techniques showed a frequency of 51.4% in dogs with antibodies (IgG) against Ehrlichia spp. There was a correlation between hyperproteinemia and titers &gt; 10,240. Nonspecific changes occurred in 24.3% (17/70) of the patients with CME, such as anemia, leukopenia, and thrombocytopenia. The results indicated that the blood count and blood smear analysis were insufficient for diagnosis and that positive serological results associated with hematological changes suggestive of ehrlichiosis in dogs can be incorrectly assigned by a veterinarian, putting animals at risk.

Molecular Evidence of Ehrlichia canis (Rickettsiales: Anaplasmataceae) in Ticks (Ixodida: Ixodidae) Associated with Dogs (Carnivora: Canidae) from Nuevo Leon, Mexico.

Background: Ehrlichia canis is transmitted by ticks causing Canine monocytic ehrlichiosis, which is considered one of the most critical tickborne pathogens. Materials and Methods: This study aimed to identify by PCR technique E. canis in ticks associated with dogs from urban and rural homes in Nuevo Leon, Mexico. The study was conducted at 13 localities in eight municipalities from 2012 to 2021. Results: A total of 1873 ticks of three species were captured: Amblyomma tenellum, Dermacentor variabilis, and Rhipicephalus sanguineus s.l. The overall infection rate of E. canis in ticks was 59.12% (149/252). Of the 15 sequences, three haplotypes were identified. Conclusion: The urban transmission cycle of canine ehrlichiosis is demonstrated, where the potential vector is the tick R. sanguineus s.l.

Clinical and pathological factors associated with Ehrlichia canis in companion dogs.

Canine monocytic ehrlichiosis (CME) is a disease caused by the Gram-negative bacteria Ehrlichia canis, a bacterium that affects domestic dogs but can also infect humans. The diagnosis implies a challenge due to its diversity in clinical manifestations. The frequency of E. canis infection, risk factors, and clinical-pathological parameters associated with seropositivity were calculated with the PROC FREQ TABLES and PROC LOGISTIC procedures of the SAS statistical software. The study showed a seroprevalence of 26.62% (156/586). Association between seropositivity and risk factors was found. The age and the presence of ticks including clinical signs such as anorexia, seizures, cough, petechiae, epistaxis, and hematochezia, as well as multiple blood and biochemical alterations were analyzed. The logistic regression analysis showed a high predictive power (c = 0.98) for CME for thrombocytopenia, leukopenia, and anemia. The high prevalence of E. canis in endemic areas makes its diagnosis difficult. Thus, clinical signs must be considered, along with blood and biochemical alterations, as a possible predictor of the disease.

Molecular occurrence and genetic diversity of Ehrlichia canis in naturally infected dogs from Thailand

Canine monocytic ehrlichiosis is cause by Ehrlichia canis resulting in hematologic disorders and severe clinical signs. The aim of this study was to scrutinize the molecular detection and genetic diversity of E. canis based on the trp36 gene in dogs from Thailand’s northern and central regions. A total of 120 dogs blood samples were amplified for trp36 gene of E. canis using the polymerase chain reaction (PCR). Forty-seven out of 120 dog blood samples (39.16%, 47/120) were positive for E. canis the trp36 DNA with 790 bp of PCR amplicon size. The factor significantly associated with E. canis infection is animal housing status (p < 0.05). Sequence and phylogenetic analysis showed that E. canis trp36 gene of Thailand isolates was clustered into 1st clade with similarity ranging from 95.65 to 100% together with the US genogroup. The 14 haplotypes of the trp36 gene shown in TCS network exhibited that haplotype #1–4 was found in Thailand. The entropy analysis of the trp36 gene illustrated 751 polymorphic sites and 271 entropy peaks of nucleic and amino acid sequences, respectively. Hence, these findings are crucial for better understanding the epidemiology of Ehrlichia infection and could be helpful for implementing control measures in Thailand.

Experimental infection and co-infection with Chinese strains of Ehrlichia canis and Babesia vogeli in intact and splenectomized dogs: Insights on clinical, hematologic and treatment responses

Animal infection models are crucial for studying various aspects of Ehrlichia canis infections. To understand the pathogenesis of the first Chinese isolate of E. canis and simulate the natural progression of canine ehrlichiosis, we developed a model with 18 Beagle dogs that consisted of E. canis initial infection (days 0–17), treatment with doxycycline or rifampicin (days 18–32), recovery (days 33–66), E. canis reinfection (days 67–91), and Babesia vogeli superinfection (days 92–116). We measured body weight and rectal temperature every other day, drew blood every 4 days for routine hematology and biochemistry tests, and for quantification of E. canis and B. vogeli by quantitative PCRs. In this study, the first isolate of E. canis from China was used to experimentally infect dogs, and the infected dogs exhibited clinical signs of acute severe ehrlichiosis, including high fever, loss of appetite, dehydration, and body weight loss, confirming the similar pathogenicity of E. canis in China as compared to isolates from other regions. Infection with E. canis and B. vogeli led to reduced body weight and fever in dogs. Doxycycline treatment led to absence of E. canis DNA in infected dogs, while rifampicin treatment lowered the blood E. canis copy number up to 1.5 folds. E. canis-free infected dogs after doxycycline treatment were successfully re-infected with E. canis, indicating dogs with antibodies are still at risk of re-infection. Super-infection with B. vogeli resulted in higher fever, more severe anemia, and a reduced number of platelets. Splenectomized dogs showed significantly higher E. canis numbers during recovery and re-infection than intact dogs. The histological changes were observed in brain, lung, kidney, liver and spleen of the infected dogs. The findings in this study provide insights into clinical and hematologic responses, as well as effective treatment options, for dogs infected with the first Chinese isolate of E. canis, and may contribute to our understanding of the diagnosis and prevention of tick-borne diseases in dogs, including canine monocytic ehrlichiosis.

Effects of Doxycycline Treatment on Hematological Parameters, Viscosity, and Cytokines in Canine Monocytic Ehrlichiosis.

This study aimed to analyze the hematological parameters, blood viscosity, and cytokines of dogs infected by Ehrlichia canis untreated and treated with doxycycline. Initially, 47 dogs were examined, and 36 were suspected to have canine monocytic ehrlichiosis, which was confirmed through molecular polymerase chain reaction tests. This study consisted of 25 dogs, with 11 being healthy and 14 testing positive for E. canis. The dogs were divided into experimental groups based on their test results, including a control group of healthy dogs (N = 11), a group of infected dogs without treatment (N = 7), and a group of infected dogs treated with doxycycline (N = 7) at a 10 mg/kg dose every 12 h for 28 days. Blood samples were taken to determine hematological parameters, viscosity, and cytokine levels. It was observed that, regardless of doxycycline treatment, there was a reduction in total leukocytes and lymphocytes in infected dogs with Ehrlichia canis. The eosinophils and platelets decreased in dogs with Ehrlichia canis infections without treatment. Monocytes, eosinophils, and platelets increased when the dogs were treated with doxycycline. Regardless of treatment, infected dogs' blood viscosity was lower than uninfected dogs. Infected dogs showed lower TNF-α and increased IL-1β. There was a correlation between the blood viscosity with the cytokines IL-10 and IL-12 in the infected dogs. The eosinophil count correlated with TNF-α in the group of infected and untreated dogs. In conclusion, treating dogs with monocytic ehrlichiosis using doxycycline can increase platelet and eosinophil levels but may also increase IL-1β and monocyte levels, exacerbating inflammation. Therefore, evaluating viscosity and cytokine levels is important when treating dogs with this condition.

Molecular Detection and Characterization of Ehrlichia canis Isolates from Three Geographic Regions in Mexico: A Retrospective Study.

Canine monocytic ehrlichiosis (CME) is the most common tick-borne disease affecting domestic dogs and other wild canids. It has a worldwide distribution and is associated with the presence of the brown dog tick. Few studies have been conducted in Mexico to identify and characterize Ehrlichia canis genetic variability. In the present study, 111 dogs of different sex, breed, and age from three geographic regions in Mexico were included. All of them had a previous history of tick infestation and/or the presence of one or more clinical signs compatible with CME. All dogs were tested by a commercial ELISA and nested PCR assay for the detection of E. canis. In addition, we analyzed the E. canis genetic diversity from the 16S rRNA gene sequences obtained in this study, along with 15 additional sequences described for E. canis in Mexico and obtained from GeneBank. Serological detection by commercial ELISA results showed overall infection rates of 85.58% (95/111), including 73.1% (30/41) in samples from Guerrero state; 75% (15/20) in Morelos; and 100% (50/50) in Chihuahua. On the other hand, molecular detection (nPCR assay) showed 31.5% (35/111) overall infection rate, with 41.4% (17/41) in Guerrero state; 55% (11/20) in Morelos; and 14% (7/50) in Chihuahua. We observed a high 16S rRNA gene sequence conservancy in most of the E. canis isolates in the three geographical areas from Mexico, including those analyzed in this research, suggesting a common geographic origin among isolates.

Correlation between canine biochemical analytes and TRP36 ELISA seropositivity for Ehrlichia canis in Brazil.

Synthetic peptides of tandem repeat proteins (TRPs) have been employed in the serologic analysis of canine monocytic ehrlichiosis (CME) and used in epidemiological studies in Brazil. Based on molecular studies of TRPs, different genotypes of Ehrlichia canis have been described, but data on their pathogenicity remain unknown. To correlate hepatic, renal, and muscular alterations in relation to different genotypes of E. canis in naturally exposed dogs using enzyme-linked immunosorbent assay (ELISA) with TRP19 and TRP36 synthetic protein antigens. Two hundred serum samples were subjected to ELISA with the antigens of TRP19 and three genotypes (US, Br, and CR) of TRP36 of E. canis circulating in Brazil. Positive sera were evaluated through eight biochemical parameters, and the results were evaluated by principal component analysis and canonical correlation. ELISA revealed that 47 (23.5%) serum samples reacted to the BrTRP36 peptide, 36 (18%) reacted to the TRP19 peptide, and 8 (4%) reacted to the USTRP36 and CRTRP36 peptides separately. The most frequent biochemical alterations observed were for CK (59.4%), ALB (31.8%), GLO (28.9%), TP (28.9%), ALP (26%), urea (24.6%), creatinine (14.4%), and ALT (14.4%). The most prominent diagnostic method in canonical correlation analysis was BrTRP36, followed by TRP19, which correlated with hyperglobulinemia and hypoalbuminemia. Antibodies that reacted against the Brazilian genotype of E. canis correlated positively with hyperglobulinemia and increases in serum urea and creatinine. According to our results, the Brazilian genotype of E. canis is related to the chronic phase of CME.

Molecular prevalence and factors associated with Ehrlichia canis infection in dogs from the North Pantanal wetland, Brazil.

Canine monocytic ehrlichiosis is a vector-borne disease caused by the obligatory intracellular bacterium Ehrlichia canis, which is distributed across tropical and subtropical regions worldwide. Its prevalence within dog populations is high in municipalities located across the Pantanal biome, but it remains unknown in Barão de Melgaço, Mato Grosso, Brazil. This study aimed to determine the molecular prevalence and factors associated with E. canis infection in dogs domiciled in Barão de Melgaço. A cross-sectional study was carried out to investigate the prevalence of E. canis infection in 369 dogs from urban and rural areas in Barão de Melgaço, North Pantanal wetland, Brazil. Initially, the dogs were examined, and, through a questionnaire, the risk factors were investigated. Blood samples were subjected to DNA extraction and PCR was performed to estimate the prevalence of E. canis infection. The molecular prevalence of E. canis infection in dogs was 42.5% and none of the studied variables were significantly associated with polymerase chain reaction (PCR) positivity (p > 0.05). The high molecular prevalence demonstrates an increased transmission of the agent across the city. This also indicates that attention needs to be paid to E. canis infection and control measures should be introduced to prevent its transmission. The demographic and clinical risk factors commonly associated with E. canis infection in this study were not associated with PCR positivity.

Prevalence of canine monocytic ehrlichiosis in dogs in and around Meerut district of Uttar Pradesh, India

Prevalence of canine monocytic ehrlichiosis in dogs in and around Meerut district of Uttar Pradesh, India