# A critical review of American Trypanosomiasis (AT) in dogs with the current distribution of cases in Brazil and a diagnostic approach for veterinary clinicians

## TL;DR

This paper reviews the current state of American Trypanosomiasis in dogs in Brazil and proposes a diagnostic approach for veterinarians.

## Contribution

The study provides a critical review and updated diagnostic guidance for AT in dogs in Brazil, highlighting regional distribution and knowledge gaps.

## Key findings

- Dogs are significant domestic hosts for T. cruzi in Brazil, with uneven regional case distribution.
- Veterinarians lack awareness of T. cruzi and its diagnostic methods in small animal clinics.
- A diagnostic flowchart is proposed to improve detection and treatment of AT in dogs.

## Abstract

Trypanosoma cruzi (Kinetoplastea: Trypanosomatidae) is the etiological agent of American Trypanosomiasis (AT). Although knowledge of natural infection by T. cruzi in dogs has increased worldwide relatively few studies have evaluated this occurrence in Brazil, with much of the available information restricted to isolated case reports. The aim of this research was to provides a critical review of AT in dogs demonstrating the current distribution of cases in Brazil and to propose a diagnostic approach for veterinary clinicians. This review comprised a comprehensive search of scientific articles and case reports published, available at PubMed, Scielo and Google Scholar websites. A combination of keywords including “American Trypanosomiasis”, “Chagas disease”, “dogs”, “T. cruzi”, and “Brazil” was used for the search. Data from this review underscores the importance of dogs as domestic hosts of T. cruzi and provides the current distribution of this infection in these animals in Brazil. Additionally, it reveals important knowledge gaps regarding veterinarian awareness of T. cruzi and its diagnostic methods in small animal clinics. The diagnostic flowchart presented here serves to guide veterinarians to perform a proper diagnostic using currently available methods. The prevention of AT in dogs faces several challenges, including the domiciliation of triatomines and the misdiagnosis of cases. These factors contribute to the ongoing presence of untreated animals, which can serve as important sources of infection for triatomine vectors and ultimate risk of human infections. For the AT control, it is important to reinforce the necessity of a One Health approach and to underscore the role of veterinarians in this process. It is pivotal to focusing on diagnosing and treating humans and dogs, controlling vectors, and improving human dwellings, especially in rural areas. Finally, cases of AT in dogs in Brazil distribute heterogeneously in all five regions of the country, with a slight predominance in the Northeast region.

The online version contains supplementary material available at 10.1007/s11259-025-11047-6.