CANINE VISCERAL LEISHMANIASIS: CLINICAL AND LABORATORY ASPECTS, RENAL HISTOPATHOLOGY, AND DIAGNOSTIC TESTS

THESIS: M. J. Veloso Soares submitted this dissertation for her Masters in Veterinary Medicine (Animal Pathology) at the School of Agrarian and Veterinary Sciences, São Paulo State University, UNESP, Jaboticabal, São Paulo Brazil, 2003 

Advisor: Professor Julieta Rodini Engrácia de Moraes 

ABSTRACT. The dog is an important reservoir of visceral leishmaniasis (VL) etiological agent. This study included clinical and laboratory evaluation, renal histopathology and PCR identification of infective agent on the spleen, liver, lymph nodes, and kidney in VL dogs. The first study included 34 symptomatic soropositive dogs (case) and 17 asymptomatic (control) of different breeds, sexes, and ages from Teresina, Piauí State. The dogs were submitted to euthanasia, and samples from spleen, liver, lymph nodes, and kidneys were collected. Renal fragments were prepared using histological techniques and stained with HE and PAS. At physical examination, lymph node hypertrophy (85.29%) and cutaneous ulcers (35.29%) were frequent in the case group. Anemia was present in 55.88% of the dogs from the case group and 11.76% from control. Renal histopathology evaluation of the case group showed that 61.76% of the dogs presented membranoproliferative glomerulonephritis (GN), and the control group 17.65%. Mesangial proliferative glomerulonephritis occurred in 32.35% of the case group dogs and in 64.70% of control. In one of the dogs from case group, amastigote forms of Leishmania were found in the middle of the inflammatory infiltrate. The second study included 25 symptomatic VL soropositive dogs (case) and 15 asymptomatic (control). PCRs used an automatic thermocycler with specific Leishmania primers. All 25 dogs from the case group had positive PCRs in spleen, liver, or lymph node, and only two from the control group. Kidney PCRs detected Leishmania DNA in eight case group animals (32%). The conclusion of the study was that canine VL, even though there were no signs detected at physical examination, the kidneys were frequently compromised and PCR is more accurate than conventional histopathology to detect the parasite presence.

KEY WORDS: dogs, kala-azar, Leishmania, renal damage, PCR.

CORRESPONDENCE TO: M. de J. Veloso Soares – Rua Penha, 76, Vila Saul Borsari, 14.883-272, Jaboticabal, São Paulo, Brasil. E-mail: mjvsoares@yahoo.com.br