Surreal image of a dog surrounded by glowing sandflies, symbolizing the hidden danger of Leishmania.

Silent Threat: Understanding Leishmania in Dogs & What You Need to Know

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Kai Mendoza in Health & Wellness November 2025 • 4 min read.

"A closer look at the prevalence, risks, and prevention of Leishmania in dogs in Pernambuco and beyond."


Leishmaniasis is a major public health concern globally, and visceral leishmaniasis (VL) is a particularly severe form of the disease. In Brazil, VL is widespread and caused by the parasite Leishmania infantum, which is transmitted through the bite of sandflies, primarily Lutzomyia longipalpis. Understanding the dynamics of this disease, especially in canine populations, is crucial for effective public health strategies.

Dogs are considered the main domestic reservoirs of Leishmania parasites. This means infected dogs can pass the parasite to sandflies, which then transmit it to humans, perpetuating the cycle of infection. This role of dogs makes them a key focus for controlling the spread of the disease.

A study was conducted in Garanhuns, a municipality in the Agreste region of Pernambuco, Brazil, to investigate the occurrence of Leishmania antibodies in dogs. This area, despite being near a known hotspot of VL, had limited prior data on canine leishmaniasis. The research aimed to determine the prevalence of the disease in dogs and identify potential risk factors.

What Does the Study in Garanhuns Reveal About Leishmania in Dogs?

Surreal image of a dog surrounded by glowing sandflies, symbolizing the hidden danger of Leishmania.

The study involved collecting blood samples from dogs in Garanhuns and testing them for Leishmania antibodies using the indirect immunofluorescence assay (IFA). A significant 16% of the tested dogs showed positive results, indicating exposure to Leishmania parasites. Although this rate is lower than in some other areas of Pernambuco, it's still a notable finding, especially compared to the estimated average for the entire state.

Researchers examined various factors to see if they were linked to Leishmania infection:

  • Age and Sex: No significant statistical correlation was found between the presence of Leishmania antibodies and the age or sex of the dogs.
  • Clinical Status: Most of the dogs that tested positive for Leishmania antibodies showed no obvious symptoms of the disease. Only a small percentage (4.9%) displayed clinical signs suggestive of visceral leishmaniasis, such as weight loss, skin issues, and enlarged lymph nodes.
  • Location: Interestingly, the study found a statistical difference in the prevalence of Leishmania antibodies depending on the specific neighborhood where the dogs lived. Areas with poorer sanitation and closer proximity to remnants of the Atlantic Forest had higher rates of infection.
These findings suggest that local environmental conditions play a crucial role in the spread of Leishmania in Garanhuns. The lack of association between age, sex, and infection status indicates that all dogs are potentially at risk, regardless of these factors.

Why These Findings Matter for You and Your Pet

The study highlights the presence of Leishmania in the canine population of Garanhuns, underlining the need for continued surveillance and preventive measures. Key actions include regular check-ups and vector control. It emphasizes the importance of community awareness and responsible pet ownership in managing and preventing the spread of this zoonotic disease.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1590/s0037-86822010000100010, Alternate LINK

Title: Prevalência De Anticorpos Antileishmania Spp Em Cães De Garanhuns, Agreste De Pernambuco

Subject: Infectious Diseases

Journal: Revista da Sociedade Brasileira de Medicina Tropical

Publisher: FapUNIFESP (SciELO)

Authors: Jessica Maria Leite Dos Santos, Filipe Dantas-Torres, Marcos Renato Franzosi Mattos, Felipe Ragner Lima Lino, Lílian Sabrina Silvestre Andrade, Rute Chamié Alves De Souza, Fábio Luiz Da Cunha Brito, Maria Edileuza Felinto De Brito, Sinval Pinto Brandão-Filho, Lucilene Simões-Mattos

Published: 2010-02-01

Everything You Need To Know

1

What exactly is Leishmaniasis, and how do dogs get infected?

Leishmaniasis, specifically visceral leishmaniasis (VL), is a disease caused by the parasite *Leishmania infantum*. It's transmitted to dogs (and humans) through the bite of infected sandflies, particularly *Lutzomyia longipalpis*. Dogs act as reservoirs, meaning they can pass the parasite to sandflies, continuing the cycle of infection.

2

What were the key findings of the *Leishmania* study conducted in Garanhuns, Brazil?

The study conducted in Garanhuns, Brazil, found that 16% of dogs tested positive for *Leishmania* antibodies, indicating prior exposure to the parasite. This is significant because it confirms the presence of *Leishmania* in an area with limited prior data. The study also revealed that environmental factors, such as poor sanitation and proximity to the Atlantic Forest, correlate with higher infection rates. Surprisingly, age and sex weren't significant risk factors.

3

What does it mean if my dog tests positive using the indirect immunofluorescence assay (IFA) for *Leishmania*?

The indirect immunofluorescence assay (IFA) is a blood test used to detect *Leishmania* antibodies in dogs. If a dog tests positive via IFA, it means they have been exposed to the *Leishmania* parasite at some point. It's important to note that a positive test doesn't automatically mean the dog is actively sick, but it does warrant further investigation and monitoring for clinical signs of visceral leishmaniasis (VL).

4

Can a dog be infected with *Leishmania* and not show any symptoms?

While some dogs in the Garanhuns study showed clinical signs of visceral leishmaniasis (VL), like weight loss, skin issues, and enlarged lymph nodes, the majority of dogs that tested positive for *Leishmania* antibodies did not show obvious symptoms. This highlights that dogs can be infected with *Leishmania infantum* and still appear healthy, contributing to the silent spread of the disease. This asymptomatic carrier state makes disease control more challenging.

5

Based on the Garanhuns study, what environmental factors contribute to the spread of *Leishmania*, and what preventative measures can be taken?

The findings in Garanhuns suggest environmental factors like poor sanitation and closeness to forested areas play a significant role in the spread of *Leishmania*. Vector control, targeting the sandfly *Lutzomyia longipalpis*, is crucial. Further research could explore specific environmental interventions to reduce sandfly populations and minimize the risk of *Leishmania infantum* transmission. Also, strategies should consider socioeconomic factors driving poor sanitation and encroachment on forested areas.

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