Abstract
Background:
Leishmaniasis is an infectious zoonotic disease caused by protozoa of the genus Leishmania, which is transmitted by hematophagous sand flies. This disease is endemic in Colombia, it is more frequently reported in rural areas and dogs are the main domestic reservoirs. This case report describes the first confirmed case of canine leishmaniasis in an urban area of Medellín, Colombia.

Case Description:
A 6-year-old intact male Belgian Malinois dog, resident in the urban area of Medellín, was presented for consultation due to lameness, lethargy and inappetence. The initial clinical presentation was acute, but one month later its condition worsened with the appearance of subcutaneous nodules, weight loss, a hirsute coat, sublingual ulcers and joint inflammation. Laboratory analysis revealed anemia, thrombocytopenia and hyperglobulinemia. Abdominal ultrasound showed splenomegaly, lymphadenomegaly and signs of chronic kidney disease. A complete qPCR panel for hemoparasites was positive for Leishmania spp. with a high parasitic load, and sequencing identified Leishmania infantum. The diagnosis was confirmed by cytology of subcutaneous nodules, which revealed amastigotes, and serology detected anti-Leishmania antibodies. Treatment with allopurinol (11 mg/kg PO q24h) was administered for 8 months, supplemented with domperidone (0.5 mg/kg PO q24h) for 4 weeks and marbofloxacin (3 mg/kg SC once then PO for 15 days). Clinical signs resolved progressively, thrombocytopenia and anaemia normalised, and follow-up qPCR tests at 7 and 9 months were negative.

Conclusion:
This is the first reported case of canine leishmaniasis caused by L. infantum in the urban area of Medellín, diagnosed by qPCR, cytology, and serology. The treatment protocol based on prolonged administration of allopurinol, domperidone and marbofloxacin achieved clinical remission, with negative follow-up qPCR results at months 7 and 9. This case highlights the need for surveillance in urban areas due to the potential displacement of vectors and the close contact between people and domestic reservoirs.

Key words: Allopurinol; Canine leishmaniasis; Dog; Domperidone; Leishmania infantum.