Worried dog in a landscape with sandfly silhouettes, symbolizing the threat of Leishmaniasis.

Is Leishmaniasis Threatening Your Dog? What You Need to Know

Lena Kashyap monogram
Lena Kashyap in Health & Wellness November 2026 • 3 min read.

"Uncover the facts about Leishmania infection in dogs and how to protect your furry friend from this emerging threat in unexpected locations."


For decades, American visceral leishmaniasis (AVL) was a disease largely confined to specific regions. However, the landscape is changing, with new cases emerging in areas previously considered low-risk. This shift means that dog owners everywhere need to be more aware of the risks and how to protect their beloved pets.

Once heavily concentrated in the northeast of Brazil, AVL has expanded its reach, now significantly impacting the southeast. This territorial expansion highlights the adaptive capacity of the vectors that transmit the disease, making it a concern even in urban centers.

A recent study focused on Florianópolis, Santa Catarina, Brazil, a region initially considered free of visceral leishmaniasis, until autochthonous cases were reported in 2011. The research highlights the importance of understanding the occurrence and spread of Leishmania in canine populations, and underscores why dog owners need to stay informed.

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Guidelines and Diagnostic Challenges

Consensus guidelines offer evidence-based approaches to diagnosing, treating, and preventing canine leishmaniosis, but veterinarians do not always follow scientifically sound methods. Infection may become patent within 1–2 months in some dogs, while other infections remain sub-patent for more than a year. A few dogs may test PCR-negative for several months before infection re-emerges and progresses, illustrating a challenge for detection and follow-up.

What are the key findings from the Florianópolis study?

Worried dog in a landscape with sandfly silhouettes, symbolizing the threat of Leishmaniasis.

The study, conducted in Florianópolis, examined 491 dogs to assess the prevalence of Leishmania infection. Researchers used two serological methods, ELISA and IFAT, to detect antibodies against Leishmania sp. The results indicated a seroprevalence of 0.4% by ELISA and 4.09% by IFAT. In total, 5.3% of the dogs tested positive for Leishmania infection.

Further investigation involved analyzing DNA samples from seropositive animals. While Leishmania sp. DNA was amplified using conventional and Real-Time PCR, it was not possible to determine the exact species of Leishmania involved. This limitation underscores the complexities in identifying specific pathogens and the need for more extensive research.

  • ELISA: 0.4% (2/491)
  • IFAT: 4.09% (24/491)
  • Total Seroreactivity: 5.3% (25/491)
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A 2025 Study of Prognosis

A study published November 18, 2025, describes canine leishmaniosis caused by Leishmania infantum as ranging from subclinical infection to systemic, chronic, and potentially fatal disease. The study aimed to identify risk factors for poor prognosis in affected dogs, focusing on demographic and epidemiological factors. Its summary says treatment response is influenced by host, vector, and environmental factors, but does not specify the study’s findings.

The Reservoir and Disease Burden

A 2022 review identifies dogs as the main reservoir of Leishmania infantum and describes canine leishmaniasis as an incurable multisystemic disease. It reports that the disease leads to death in symptomatic dogs when untreated. The parasite also causes visceral, cutaneous, and mucosal leishmaniasis in people in the Mediterranean Basin, North Africa, South America, and West Asia.

A One Health Perspective

An article on clinical management of canine leishmaniosis versus human leishmaniasis invokes the One Health initiative. The initiative seeks to rapidly detect emerging or re-emerging infectious diseases in humans and animals. The article identifies deforestation, some agricultural practices, and the appearance of new foci of Leishmania infantum with alternative reservoirs as epidemiological situations it aims to help prevent.

These findings are particularly important because Florianópolis was previously regarded as a disease-free region for visceral leishmaniasis. The detection of autochthonous cases and the presence of Leishmania DNA suggest that the disease is emerging in this area, necessitating a thorough epidemiological investigation.

What Does This Mean for Dog Owners?

The emergence of leishmaniasis in new regions underscores the need for heightened awareness and proactive measures. Dog owners should consult with their veterinarians about regular screening, especially if living in or traveling to areas where the disease has been reported. Preventive measures, such as using insect repellents effective against sandflies (the vectors of Leishmania) and avoiding outdoor activities during peak sandfly hours, can also help reduce the risk of infection.

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Diagnosis and Public Health

A 2022 update reports that canine leishmaniasis diagnosis has evolved through analysis of new samples using novel molecular techniques. It also describes the implications of the disease’s epidemiology, diagnosis, treatment, and prevention as fundamental to public health. The source summary does not name the techniques or provide specific performance data.

Forecasting Future Incidence

A 2026 forecasting study compiled long-term positivity trends and compared them with regional temperature records from the Servei Meteorològic de Catalunya. To forecast future incidence, it adapted an existing single-season SEIRD model of human leishmaniasis into a multiseason, dual-host system involving dogs and sandflies. The source describes this modeling approach but does not provide forecast results in the supplied summary.

Infection among dogs already suspected

  • 6.4% of dogs suspected of leishmaniasisAmong dogs suspected of leishmaniasis in the United States and Canada, 6.4% were found to be infected with L. infantum. The figure describes a selected group, not dogs generally.[1]

What canine transmission evidence suggests

Current evidence points mainly to direct dog-to-dog transmission in North America, while leaving sand fly transmission as a possible additional route. That distinction means the evidence does not establish sand flies as the only route for canine infection there.[1]

In mammalian hosts, the amastigote form occurs inside mononuclear phagocytes in the skin, bone marrow, and visceral organs. This describes where that parasite form is found, not how frequently infection occurs.[1]

How other canine evidence compares

Visceral leishmaniasis is occasionally diagnosed in the United States in dogs imported from endemic regions, and may present with primarily cutaneous or visceral signs. Imported-dog diagnoses provide context for canine cases but do not establish local transmission.[1]

The source describes direct vertical and horizontal transmission among dogs in North America, while saying those dogs are not known to be infected by sand fly vectors. This adds transmission routes to the regional picture without resolving every possible route.[1]

Persistent renal proteinuria and non-regenerative anemia are described as clues that can raise suspicion in an at-risk dog; the excerpt does not present them as confirmation of infection.[1]

Sources

  1. Leishmaniasis - Companion Animal Parasite Council (capcvet.org)

About this Article -

Written with AI assistance from published research, and reviewed by the Mystum team. See our About page for more information.

Everything You Need To Know

1

What is Leishmaniasis?

Leishmaniasis is a disease caused by parasites of the genus Leishmania. It is transmitted to dogs through the bite of infected sandflies. The disease can manifest in various forms, including visceral leishmaniasis (AVL), which affects internal organs. Understanding the nature of Leishmania infection is the first step to protecting your dog.

2

What did the Florianópolis study find?

The Florianópolis study used two serological methods, ELISA and IFAT, to detect antibodies against Leishmania sp. in dogs. ELISA (enzyme-linked immunosorbent assay) showed a seroprevalence of 0.4%, while IFAT (indirect fluorescent antibody test) showed 4.09%. Overall, 5.3% of the dogs tested positive for Leishmania infection. These methods are crucial for identifying infected dogs, even before they show symptoms, allowing for early intervention.

3

Why is the emergence of Leishmaniasis in Florianópolis significant?

The study found that the disease, Leishmaniasis, is emerging in the region, which was previously considered disease-free. The detection of autochthonous cases, cases originating within the area, and the presence of Leishmania DNA indicate the spread of the disease. This means that dog owners in the region need to be aware of the risks and take preventative measures. This shift underscores the adaptive capacity of the vectors that transmit the disease and the need for understanding the disease.

4

How can I protect my dog from Leishmaniasis?

If your dog is at risk, it is essential to consult with your veterinarian about regular screening for Leishmania infection. Also, using insect repellents effective against sandflies, the vectors of Leishmania, is crucial, particularly during peak sandfly hours. Avoiding outdoor activities during these times can also reduce the risk. These measures help reduce the chances of your dog contracting Leishmania infection, offering peace of mind and better health outcomes.

5

What is the significance of Leishmaniasis spreading to new areas?

American visceral leishmaniasis (AVL) has expanded its reach, impacting new areas like Florianópolis. This expansion highlights the need for greater awareness among dog owners everywhere. The implications include increased vigilance, regular screening, and the use of preventative measures, especially in areas with reported cases. The goal is to protect dogs from this emerging threat. The disease is no longer confined to specific regions.

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