Hematological disorders detected in dogs infected by Hepatozoon canis in a municipality in Mato Grosso do Sul State, Brazil

Longitudinal dynamics and health impact of Hepatozoon procyonis (Apicomplexa: Hepatozoidae) on naturally infected ring-tailed coatis Nasua nasua (Carnivora: Procyonidae) from Midwestern Brazil

This study aimed to morphologically and molecularly detect Hepatozoon procyonis in ring-tailed coatis' (Nasua nasua) blood and associated ticks from central-western Brazil, Campo Grande, Mato Grosso do Sul state and also evaluate the impact of the protozoa in blood parameters and coati´s health. Samplings were performed in a conservation area Parque Estadual do Prosa (PEP) and in a Brazilian Air Force Private Area namely Vila da Base Aérea (VBA), between March 2018 and April 2019. We collected 165 blood samples, 61 from recaptured coatis. Peripheral blood smears were stained with Romanovsky-type stain for H. procyonis parasitemia assessment. DNA extracted from blood samples and ticks (Amblyomma spp.) were submitted to a nested PCR (nPCR) assay based on the 18S rRNA gene for Hepatozoon spp. Out of 104 individuals sampled, 80 (77%) were positive for H. procyonis in at least one capture. Overall, 67/165 (40.6%) blood smears showed H. procyonis gametocytes (PEP: 41/63 - 65%; VBA: 26/102 - 25.5%). Parasitemia based on 500 assessed leucocytes ranged from 1 (0.2%) to 50 (10%) and 1 (0.2%) to 25 (5%), from animals sampled in PEP and VBA, respectively. Fluctuation on the parasitemia was observed during recaptures. nPCR results showed higher positivity when compared to blood smears, i.e. 112/165 (68%) positive blood samples [PEP: 41/63 (65%), VBA: 26/102 (25.5%)]. In total, 63/248 (25.4%) tick DNA samples were positive at nPCR for Hepatozoon sp., including 32/87 (37%) pools (1 to 10 larvae) of Amblyomma larvae, 21/105 (20%) pools (1 to 5 nymphs) of Amblyomma sculptum nymphs, 9/43 (21%) pools (1 to 5 nymphs) of Amblyomma dubitatumnymphs, and 1/12 (8%) A. sculptum adult female. The partial 18S rRNA sequence from one coati's blood sample and one representative of each positive tick species randomly selected from each area for sequencing (1,000 bp) showed 100% identity with sequences of H. procyonis from GenBank previously detected in coatis. Regarding H. procyonis infection, no statistical differences were obtained when comparing males vs. females (p-value 0.67), immature animals vs. adults (p-value 0.31), rainy vs. dry season (p-value 0.51) and sampling location (p-value 0.42). No noticeable alteration in blood parameters or heath status was observed in parasite animals. H. procyonis circulates in a high prevalence in coatis from central-western Brazil. Parasitemia fluctuates among different coatis' recaptures and apparently the infection has no influence in coatis' hematological and clinical parameters.

Characterization of serum protein electrophoresis patterns and C-reactive protein in canine tick-borne diseases

Background and Aim

Canine tick-borne diseases are important diseases with a worldwide distribution. In Thailand, the most important canine tick-borne diseases are ehrlichiosis, babesiosis, and hepatozoonosis. This study aimed to determine the serum protein electrophoresis patterns (SPEPs) and C-reactive protein (CRP) levels associated with Ehrlichia canis , Babesia canis, or Hepatozoon canis single infections.

Materials and Methods

A total of 650 canine blood samples were collected from animal hospitals and clinics in Bangkok and its vicinity to examine health status and blood parasite infection. Suspected blood parasite infections were examined by buffy coat thin blood smear and confirmed by polymerase chain reaction. Normal dog and positive E. canis , B. canis, and H. canis single infections and serum protein profiles were determined by agarose gel electrophoresis. CRP concentration was measured by fluorescent immunoassay.

Results

In dogs infected with E. canis, B. canis, and H. canis single infections, albumin levels and A/G ratios significantly decreased, whereas β2-globulin levels increased (p<0.05). The γ-globulin level significantly increased in E. canis and H. canis infections (p<0.05). A monoclonal gammopathy pattern wasi observed in E. canis and B. canis sngle infections, whereas β-γ bridging patterns and increased β- and γ-globulin fractions were found in H. canis single infections. The CRP level increased in dogs with blood parasite single infections and may be related to the pathogenesis of the infection.

Conclusion

SPEPs and CRP levels can be used to monitor health status and blood parasite problems in infected dogs.

Haemogregarines and Criteria for Identification

Simple Summary

Taxonomic classification of haemogregarines belonging to Apicomplexa can become difficult when the information about the life cycle stages is not available. Using a self-reporting, we record different haemogregarine species infecting various animal categories and exploring the most systematic features for each life cycle stage. The keystone in the classification of any species of haemogregarines is related to the sporogonic cycle more than other stages of schizogony and gamogony. Molecular approaches are excellent tools that enabled the identification of apicomplexan parasites by clarifying their evolutionary relationships.

Abstract

Apicomplexa is a phylum that includes all parasitic protozoa sharing unique ultrastructural features. Haemogregarines are sophisticated apicomplexan blood parasites with an obligatory heteroxenous life cycle and haplohomophasic alternation of generations. Haemogregarines are common blood parasites of fish, amphibians, lizards, snakes, turtles, tortoises, crocodilians, birds, and mammals. Haemogregarine ultrastructure has been so far examined only for stages from the vertebrate host. PCR-based assays and the sequencing of the 18S rRNA gene are helpful methods to further characterize this parasite group. The proper classification for the haemogregarine complex is available with the criteria of generic and unique diagnosis of these parasites.

Hematological profile of blood parasitic infected dogs in Southern Thailand

Background and Aim:

Tick-borne pathogens such as Babesia canis, Hepatozoon canis, and Ehrlichia canis can cause serious disease in canines. Each blood parasite can be associated with different hematological characteristics in infected dogs. Identification of hematological alterations during routine laboratory screening of blood samples from dogs displaying clinical signs is essential for diagnosing blood parasitic infections. This study aimed to evaluate parasitic infections and hematological alterations in blood samples of infected dogs in Southern Thailand.

Materials and Methods:

A total of 474 blood samples were collected from dogs presented at the Veterinary Teaching Hospital of the Prince of Songkla University between 2016 and 2019. An automatic hematology analyzer was used to establish hematological values; peripheral blood films were screened for blood parasites and their detection was associated with hematological alterations to determine the odds ratio (OR).

Results:

This study found that E. canis (n=127) was the most common blood parasite infecting dogs in southern Thailand, followed by H. canis (n=100) and B. canis (n=24). Hematological alterations caused by Ehrlichia infections included anemia, thrombocytopenia, monocytosis, and eosinophilia (OR=14.64, 17.63, 20.34, and 13.43, respectively; p<0.01). The blood samples of Hepatozoon-infected dogs were characterized by anemia, thrombocytopenia, leukocytosis, neutrophilia, and monocytosis (OR=6.35, 3.16, 12.80, 11.11, and 17.37, respectively; p<0.01). Anemia, thrombocytopenia, eosinopenia, and lymphopenia (OR=10.09, 33.00, 20.02, and 66.47 respectively; p<0.01) were associated with B. canis-infected dogs.

Conclusion:

These data support the fact that hematological abnormalities are a hallmark for the identification of tick-borne infections. The hematological values, hereby reported, can be used as a guideline for the clinical diagnosis of canine blood parasitic infections in Southern Thailand.

Hepatozoon canis infection causing a strong monocytosis with intra-monocytic gamonts and leading to erroneous leukocyte determinations

In this case report, a Swedish flat-coated retriever was diagnosed with an extensive Hepatozoon canis infection. The dog had a prominent monocytosis (14.0 × 10⁹ /L) with H canis gamonts detected in most monocytes, but none were found in the neutrophils. On the hematology system ADVIA 2120 peroxidase (PEROX) cytogram, most leukocytes were seen as a distinct cell population above the lymphocytes, which indicated that most of the cells were larger than lymphocytes and had weak myeloperoxidase staining. This distinct cell cluster appeared to be of a single cell type but was incorrectly divided by the ADVIA 2120 into lymphocytes, monocytes, and large unstained cells (LUC). The total leukocyte counts on the ADVIA 2120 WBC basophil (BASO) channel were much higher than that on the WBC PEROX count. The WBC BASO cytogram appeared abnormal with two parallel cell populations, so the BASO WBC count was considered erroneous. Polymerase chain reaction and DNA sequencing verified H canis infection. The dog was treated with subcutaneous imidocarb dipropionate (6 mg/kg) injections every other week. Post-treatment hematology analyses indicated that the percentage of parasitized leukocytes decreased from 40% to 5% about 4 weeks after the start of treatment and were not found in any monocytes 6 weeks after the beginning of the treatment. In conclusion, H canis infection in this dog was associated with a strong monocytosis, and gamonts were present in many monocytes, which caused aberrant automated leukocyte counts to occur.