What question did this study set out to answer?

To characterize Babesia gibsoni in a domestic dog with clinical symptoms in Brazil, assessing its genetic diversity.

May 16, 2026Open Access

Babesia gibsoni in Brazil: First multilocus molecular characterization in a domestic dog with clinical, hematological and morphological data

Key Points

To characterize Babesia gibsoni in a domestic dog with clinical symptoms in Brazil, assessing its genetic diversity.
Conducted multilocus molecular characterization of Babesia gibsoni using PCR in a single Dachshund dog.
Analyzed four molecular markers: cytb, cox3, hsp70, and 18S rRNA to confirm infection and assess genetic diversity.
Constructed haplotype networks and calculated diversity indices for genetic variability assessment.
Confirmed Babesia gibsoni infection in a clinically affected dog with persistent anemia and fever.
Cytb and cox3 genes exhibited high genetic variability and suitable for defining intraspecific diversity.
Study indicates Babesia gibsoni is likely underdiagnosed in Brazil, necessitating further molecular surveillance.

Abstract

Canine babesiosis is a disease caused by protozoa of the genus Babesia , an important hemoparasite in veterinary clinical practice. In Brazil, Babesia vogeli predominates; however, Babesia gibsoni , common in Asia and the United States, has emerged globally with distinct diagnostic, therapeutic, prophylactic, and prognostic features. In the present study, we report the first multilocus molecular characterization of B . gibsoni in Brazil with supported clinical, laboratory and morphological data. A Dachshund dog from the Federal District presented with nonspecific clinical signs, including fever, dehydration, and persistent anemia. Babesia infection was confirmed by PCR and further characterized using four molecular markers ( cytb , cox3 , hsp70 , and 18S rRNA). Phylogenetic and sequence identity analyses confirmed the species as B . gibsoni . Haplotype networks were constructed, and diversity indices were calculated, revealing significant genetic variability within the species. The Brazilian isolate clustered within the dominant haplotype for the 18S rRNA gene. This network suggests a possible recent population expansion of the pathogen. The cytb and cox3 genes exhibited high genetic variability, demonstrating their suitability as markers for intraspecific diversity analyses. Our findings suggest that B . gibsoni infections may be underdiagnosed in Brazil. Furthermore, considering the genetic diversity and widespread distribution of this pathogen, epidemiological, phylogenetic, and phylogeographic studies are essential to enhance understanding of its occurrence and impact within the country. Although this study is limited by the evaluation of a single case, it emphasizes the importance of molecular surveillance in canine babesiosis and highlights B . gibsoni , an emerging pathogen, as a critical differential diagnosis in the clinical evaluation of dogs in Brazil. • First multilocus molecular evidence of Babesia gibsoni causing canine babesiosis in Brazil • Molecular and hematological findings confirmed infection in clinically affected dogs • Cytb and cox3 haplotype networks revealed high genetic diversity of B. gibsoni • Results underscore the need for species-level molecular surveillance in Brazil

Babesia gibsoni in Brazil: First multilocus molecular characterization in a domestic dog with clinical, hematological and morphological data

Key Points

Abstract

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