Leishmania in Dogs – Causes, Treatment, and Prevention

What Is Leishmania?

Leishmania infantum is a microscopic parasite passed to dogs by the bite of infected sand flies. Once inside the body it can spread to the skin, lymph nodes, and even the kidneys, causing weight loss, sores, and organ damage. Without treatment many dogs grow steadily weaker, so quick action is vital.

How Infection Happens

Sand flies are most active at dusk and dawn from spring through late fall. They draw blood from a sick animal, pick up the parasite, and pass it on to the next dog they bite. Dogs can be silent carriers for months before showing signs.

Diagnosis

Our vet will check travel or living history, do a detailed exam, and run tests such as antibody ELISA or PCR. Blood chemistry and urine tests help grade kidney health, which guides the treatment plan. ^[1]

Treatment Options

First-Line Medicines

• Meglumin antimoniate + allopurinol – 28-day injections with at least six months of oral allopurinol; success in reducing parasite load is high. ^[1][3]
• Miltefosine + allopurinol – once-daily oral liquid for 28 days followed by allopurinol; useful when injections are not possible and backed by long-term studies. ^[2][5]
• Allopurinol alone – may be used in mild stage I cases or as long‐term maintenance after combination therapy. ^[1]

Adjunct or Second-Line Choices

• Amphotericin B lipid complex – reserved for resistant or severe cases; requires close kidney monitoring. ^[1]
• Domperidone or nucleotides + AHCC – immune boosters that may aid recovery in early disease or after drug therapy. ^[1]

Supportive Care

• Renal diet and regular blood checks for kidney support.
• Topical antibiotics for skin ulcers if present.
• Anti-inflam­matory drugs when joint pain or eye swelling occurs.

Prevention and Monitoring

• 4 % deltamethrin collars or spot-on permethrin keep sand flies from biting. ^[4][7]
• Vaccines such as CaniLeish® or the new LmCen-/- candidate help lower the risk of infection and disease flare-ups. ^[5]
• Keep dogs indoors at dusk, use fine-mesh screens, and clean yard debris where flies breed.
• Re-test treated dogs every 3–6 months to spot relapse early. ^[3]

Prognosis

Most dogs improve within one to two months of starting therapy, yet relapses are common. Life-long monitoring and, in many cases, extended low-dose allopurinol are needed to keep the parasite under control. ^[1][3]

References

1. LeishVet. Field Guide to Canine Leishmaniosis – 2024 Update. [oai_citation:0‡leishvet.org](https://www.leishvet.org/wp-content/uploads/2024/04/FS-ALIVE24-canine.pdf?utm_source=chatgpt.com)
2. Paltrinieri et al. “Clinical and Laboratory Response of Dogs Treated with Miltefosine + Allopurinol,” Pathogens, 2023. [oai_citation:1‡pmc.ncbi.nlm.nih.gov](https://pmc.ncbi.nlm.nih.gov/articles/PMC10610677/?utm_source=chatgpt.com)
3. Mosteiro et al. “Critically Appraised Topic on Canine Leishmaniosis,” Veterinary Sciences, 2024. [oai_citation:2‡mdpi.com](https://www.mdpi.com/2306-7381/11/6/231?utm_source=chatgpt.com)
4. “Insecticide-Impregnated Dog Collars for VL Control,” Parasites & Vectors, 2024. [oai_citation:3‡parasitesandvectors.biomedcentral.com](https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-024-06474-4?utm_source=chatgpt.com)
5. Chakravarty et al. “LmCen−/− Vaccine Protects Against CVL,” NPJ Vaccines, 2025. [oai_citation:4‡nature.com](https://www.nature.com/articles/s41541-025-01070-8?utm_source=chatgpt.com)
6. World Association for Veterinary Dermatology. “Evidence-Based Guidelines for Canine Leishmaniosis Treatment,” 2023. [oai_citation:5‡wavd.org](https://wavd.org/continuing-education/consensus-guidelines-original/woconsensus-statement-diagnosis-evidence-based-clinical-practice-guidelines-for-treatment-prevention-canine-leishmaniosis/?utm_source=chatgpt.com)