CASE REPORTS An Atypical Case of Leishmaniasis Associated with Chronic Duodenitis in a Dog Ignacio Ayala, DVM, PhD, Luis Jesus Bernal, DVM, PhD, Juan Diego Garcia-Martinez, DVM, PhD, Miguel Angel Gomez, DVM, PhD, Jose Antonio Navarro, DVM, PhD, Antonio Bernabe, DVM, PhD ABSTRACT We describe an atypical case of duodenal leishmaniasis in a boxer dog presenting with chronic diarrhea and poor general condition. Antidiarrheic therapy was previously administered without success and inflammatory bowel disease localized to the small intestine was suspected, given the chronic clinical signs and by ruling out other known causes of gastrointestinal inflammation. Endoscopic biopsy of duodenum showed a moderate increase in lamina propria lymphocytes, plasma cells, and macrophages. Basophilic bodies were seen in the cytoplasm of numerous macrophages, suggestive of Leishmania spp, confirmed by immunostaining, and a diagnosis of granulomatous duodenitis associated to Leishmania infection was made. After 7 mo of therapy, a significant clinical improvement and weight gain were observed, and endoscopic histology showed no evidence of Leishmania. A progressive decline of anti- leishmanial antibody titer was also observed during follow-up. This report emphasizes the importance of atypical symptoms and the unusual location of visceral leishmaniasis, suggesting the need to consider leishmaniasis in the differential diagnosis of canine chronic enteritis, especially in endemic areas. (J Am Anim Hosp Assoc 2017; 53:101–106. DOI 10.5326/JAAHA-MS-6401) Introduction Canine leishmaniasis (CanL) due to Leishmania infantum is a major global zoonosis potentially fatal to humans and dogs, the latter comprising the main reservoir of infection. 1 It is endemic in more than 70 countries of the world, and it is present in regions of southern Europe (Mediterranean region), Africa, Asia, and South and Central America, and has also been reported in the United States. 2 CanL presents with a broad spectrum of clinical signs and with various degrees of severity: classic CanL appears clinically as a chronic wasting disease with anemia, cutaneous lesions, and generalized lymphoadenopathy. Some dogs also show epistaxis, arthritis, keratoconjunctivitis, and uveitis, and, in the later stages of the disease, chronic kidney disease may appear. 3 Diarrhea, originating from either the small or large intestine, is another feature, varying from 3–8% to as high as 30%. 4,5 However, most authors consider chronic diarrhea as an unusual clinical presen- tation of CanL. 6 We present an atypical case of canine leishmaniasis in which the primary clinical sign was chronic diarrhea of small intestinal origin with none of the other typical clinical features, except for nonspecific ones such as chronic wasting and anemia. Case Report A 26-kg, 1-yr-old intact male boxer was referred for assessment because of a 4-wk history of small intestinal diarrhea with increasing volumes of semiformed feces. There was no tenesmus, vomiting, or hematochezia. The major clinical signs were small intestinal diarrhea and poor body condition (score 3/9; ideal weight 5/9). His diet consisted of a commercial hydrolysed protein diet a , prescribed by the referring veterinarian in an 8-wk dietary trial with minimal improvement. The dog had been regularly vaccinated and From the Animal Medicine and Surgery Department (I.A., L.J.B., J.D.G.-M.); and Veterinary Pathology Department (M.A.G., J.A.N., A.B.), University of Murcia, Murcia, Spain. Correspondence: iayape@um.es (I.A.) CanL (canine leishmaniasis); CRP (C-reactive protein); H-E (hema- toxylin and eosin); IBD (inflammatory bowel disease); PO (per os) Q 2017 by American Animal Hospital Association JAAHA.ORG 101