Description of an outbreak of canine rangeliosis in the northwest littoral of Uruguay | Descripción de un foco de rangeliosis canina en el litoral noroeste del Uruguay

English. Canine rangeliosis is a disease caused by the protozoan Range­lia vitalii and transmitted by ticks. It affects domestic and wild canines, causing hemolytic anemia and thrombocytopenia. In Uruguay it has been reported in the following counties: Arti­gas, Salto and Treinta y Tres. The present study describes a ca­nine rangeliosis outbreak in the northwest littoral of Uruguay, diagnosed by epidemiological, clinical, hematological, anato­mopathological and molecular techniques (PCR / sequencing). The study was based on 9 cases of dogs, Fawn Brittany Grif­fon breed, used for hunting; from a farm near Quebracho, Pa­ysandú County. Eight animals died and one responded to the treatment. The main clinical signs were apathy, jaundice, fever, bloody diarrhea and bleeding from nostrils and tips of the ears. The hematological findings were anemia, thrombocytopenia and leukocytosis. Main macroscopic lesions were characterized by paleness, generalized jaundice, splenomegaly, lymphadenomeg­aly, and hepatomegaly. The principal histopathological lesions were interstitial nephritis with tubular degeneration and necro­sis, myocarditis, centrolobulillar hepatic necrosis, edematous and congestive lung, lymphoadenitis and perivascular mononu­clear inflammatory infiltration in spleen. In several organs were observed R. vitalii zoites inside the cytoplasm of endothelial cells. In some animals and as well as in dog kennels were pres­ent Amblyomma aureolatum. DNA was extracted from blood of two cases and a fragment of the 18s ribosomal RNA gene of Piroplasm was amplified by PCR. The sequence obtained was compared to the sequences registered in the GenBank using the BLAST tool. The result showed a homology between 99-100% with R. vitalii.

Spanish; Castilian. La rangeliosis canina es una enfermedad causada por el proto­zoario Rangelia vitalii y transmitida por garrapatas. Afecta ca­ninos domésticos y silvestres, provocando un cuadro de anemia hemolítica y trombocitopenia. En Uruguay ha sido reportada en los Departamentos de Artigas, Salto y Treinta y Tres. El presente trabajo describe un foco de rangeliosis canina en el litoral oeste del Uruguay, diagnosticado mediante estudios epidemiológicos, clínicos, hematológicos, anatomopatológicos y técnicas mole­culares (PCR/secuenciación). El estudio se basó en 9 casos de perros raza Griffon Fauve de Bretagne provenientes de un pre­dio rural próximo a Quebracho, Departamento de Paysandú. De los animales ocho murieron y uno respondió al tratamiento. Los principales signos clínicos fueron apatía, ictericia, fiebre, diarrea con sangre y sangrado por narinas y punta de orejas. Hematoló­gicamente se constató anemia, trombocitopenia y leucocitosis. Los hallazgos macroscópicos se caracterizaron por palidez, ic­tericia generalizada, esplenomegalia, linfoadenomegalia y hepa­tomegalia. Al examen histopatológico se destacó: nefritis inters­ticial con degeneración y necrosis tubular, miocarditis, necrosis hepática centrolobulillar. Congestión y edema pulmonar, linfoa­denitis, y en bazo infiltrado inflamatorio difuso perivascular de tipo mononuclear. En diversos órganos se visualizaron zoítos de R. vitalii intracitoplasmáticas en las células endoteliales. En al­gunos animales así como en los caniles de los perros se constató presencia de Amblyomma aureolatum. De dos casos se extrajo ADN de sangre y mediante PCR se amplificó un fragmento del gen 18s ARN ribosomal de Piroplasmas. La secuencia obtenida fue comparada con secuencias registradas en el GenBank utili­zando la herramienta BLAST. El resultado reveló una homolo­gía entre 99-100% con R. vitalii.