Leishmaniosis is a disease with limited information related to epidemiologic and clinical aspect in cats. Regardless, it seems to be an emerging disease in this species. Clinical signs are rare and normally manifest as cutaneous and/or ocular changes, with or without visceral involvement. Diarrhoea is a very uncommon clinical sign and it is frequently associated with chronic renal disease in dogs.
In this case report, the authors describe a case of a 10-year-old male neutered cat that was presented for diarrhoea with 4 weeks duration. Despite treatment with antibiotics and changes in diet, no improvement was seen.
On physical exam, generalized lymphadenomegaly was noted. Mild non-regenerative anaemia and proteinuria were detected. Empirical treatment with fenbendazole (50mg/kg once daily during 5 days), protein hydrolysed diet and probiotics was started.
Although there was initial improvement, diarrhoea persisted and the anaemia worsened. Additional exams were performed and all results came back negative. An abdominal ultrasound was performed and splenomegaly was detected. The spleen also showed a honey-comb appearance. Cytology of the spleen and lymph nodes was performed and Leishmania spp. amastigotes were detected. Cytology of the bone marrow also showed the same. Anti-Leishmania antibodies were also detected by immunofluorescence assay at a titre of 1:160.
Gastrointestinal biopsies via endoscopy were obtained to rule out other primary gastrointestinal diseases and Leishmania spp. amastigotes were also detected and confirmed by immunohistochemical staining. The ultimate definitive diagnosis was a granulomatous gastroenteritis caused by and infestation of Leishmania spp.
The cat was treated with allopurinol (10mg/kg twice daily) and a dietary supplement (Impromune® ½ tablet orally once daily). After one month of treatment the diarrhoea resolved, the cat’s weight improved and the protein:creatinine ratio had normalized.
Diarrhoea in dogs with Leishmania spp. is normally a consequence of renal disease. In cats, this clinical sign had never been reported as primary in those infected with Leishmania spp.
Concurrent diseases that can lead to immunosuppression can favour infection of cats with Leishmania spp. Despite this, after several exams, this was ruled out in this case.
An important note is the need to perform GI biopsies in cats that present with this clinical sign and live in endemic areas to rule out the disease in those that don’t respond to traditional empirical treatment. It is common to administer immunosuppressive drugs in situations with financial restraints and this type of treatment can be harmful.
This case reports a cat with diarrhoea as the main clinical sign caused by an infection by Leishmania spp. Since it is such a rare disease in cats, it can by underdiagnosed. Therefore it is important to consider it as a differential in those that live in endemic areas.