Chronic diarrhea secondary to canine leishmaniosis: Case series

Chronic diarrhea is a clinical sign associated with canine leishmaniosis, varying from 3 % to 30 % of prevalence. However, its occurrence in dogs has been mostly associated with chronic kidney or liver disease. Leishmania organisms can cause inflammation of the digestive tract with chronic diarrhea as the only clinical manifestation, although it has been poorly documented in dogs. The aim of this retrospective observational study was to describe dogs with chronic diarrhea as the main clinical sign associated with leishmaniosis. All cases had a complete blood count, biochemistry, urinalyses, and diagnostic tests for leishmaniosis. Exclusion criteria included renal or hepatic disease and/or previous diagnosis of gastrointestinal disease. Twenty-three dogs were included. Small bowel diarrhea was present in 7/23 (30.4 %), large bowel diarrhea in 9/23 (39.2 %) and mixed diarrhea in 7/23 (30.4 %). Gastrointestinal biopsies were performed in 8/23 dogs and Leishmania amastigotes were found in all of them. In the others, leishmaniosis was diagnosed by serology in 10/15 dogs (66.7 %), serology plus blood PCR in 3/15 (20.0 %), lymph node cytology in 1/15 (6.7 %), and blood PCR in 1/15 (6.7 %). All dogs treated had a complete resolution of diarrhea with specific treatment for leishmaniosis alone, based on meglumine antimoniate (75-100 mg/kg SID SC for 1 month) plus allopurinol (10 mg/kg BID PO ≥ 6 months). This study suggests that leishmaniosis should be also included in the differential diagnosis of dogs from endemic areas presenting with the primary problem of large-bowel, small-bowel, or mixed-bowel chronic diarrhea.