Evaluation of Seroprevalence and Risk Factors of Heartworm Infection for Dogs in Rio de Janeiro with Access to
Mariana Guedes1, Tamiris Gomes2, Bruno Alberigi3
1Zoetis Indústria de Produtos Veterinários Ltda, Rua Dr. Chucri Zaidan, 1240, 4º andar, São Paulo, SP, Brazil, CEP: 04711-130. mariana.guedes@zoetis.com.
Insights
Heartworm infection in dogs is prevalent in Rio de Janeiro, Brazil. Short-haired dogs and those with tick-borne diseases face higher risks, highlighting the need for targeted prevention strategies.
Area of Science:
- Veterinary Parasitology
- Canine Epidemiology
- Zoonotic Disease Research
Background:
- Heartworm disease (caused by Dirofilaria immitis) is a serious, potentially fatal condition in dogs.
- Previous reports indicate a high prevalence of heartworm infection in Rio de Janeiro, Brazil.
- Understanding regional variations and risk factors is crucial for effective control.
Purpose of the Study:
- To assess the seroprevalence of heartworm infection in dogs with veterinary access in Rio de Janeiro.
- To identify risk factors associated with Dirofilaria immitis infection in this canine population.
- To analyze geographical differences in heartworm prevalence across the state.
Main Methods:
- A cross-sectional study involving 1787 canine blood samples from 135 veterinary practices across 8 regions of Rio de Janeiro.
- Diagnostic testing for Dirofilaria immitis antigens and antibodies against tick-borne pathogens using immunochromatography.
- Data collection on owner-reported living conditions, dog characteristics, demographics, and clinical signs to evaluate risk factors.
Main Results:
- The overall prevalence of heartworm infection was 8.2%, with significant regional variation (2.4% in mountainous areas to 29.4% in the eastern area).
- Key risk factors identified were short hair coat (OR 2.62) and co-infection with tick-borne disease parasites (OR 3.83).
- Reported clinical signs were consistent with heartworm disease.
Conclusions:
- Heartworm infection remains a significant concern in the canine population of Rio de Janeiro, with notable geographical disparities.
- Short coat and concurrent tick-borne infections are significant risk factors, suggesting complex transmission dynamics.
- Further investigation is needed to determine the roles of veterinary diligence and owner compliance in infection rates.
Abstract:
Heartworm infection is a chronic disease with clinical signs and effects ranging from an asymptomatic condition to severe disease and death. The prevalence of heartworm disease in the state of Rio de Janeiro has been reported to be high (21.3%). The present study was conducted to evaluate the seroprevalence and risk factors of heartworm infection for the canine population with access to veterinary services in different areas of the state of Rio de Janeiro, Brazil. A total of 1787 canine blood samples were obtained from 135 practices across 8 different areas of Rio de Janeiro state (Rio de Janeiro municipality, São Gonçalo municipality, Niterói municipality, Baixada Fluminense, and the northern, southern, eastern, and mountainous areas) and tested for the presence of Dirofilaria immitis antigens and antibodies against several tick-borne disease pathogens using a commercial immunochromatography technique (Vetscan® Flex 4 Rapid Test; Zoetis; NJ USA). Pet owners reported living conditions, physical characteristics, demographics, and clinical signs for evaluation of risk factors for heartworm infection. Only two evaluated risk factors were shown to enhance the risk for D. immitis infection, including having a short hair coat vs. having a medium or long hair coat (OR 2.62) or positive for antibodies to tick-borne disease parasites (OR 3.83). Clinical signs reported for dogs with heartworm disease were typical for that condition. The overall prevalence of heartworm disease in the state was 8.2%, ranging from 2.4% in the mountainous region to 29.4% in the eastern area. It could not be determined if veterinarians were not diligent about dispensing heartworm preventatives or if poor levels of compliance by dog owners were responsible for higher infection rates in some areas of the state.
