Differential diagnoses in 83 dogs with icterus

Abstract

Icterus (jaundice) is a yellowish pigmentation resulting from the depositing of bilirubin in tissues due to its high plasmatic concentration. The pathogenesis of icterus includes metabolic changes or obstructed bilirubin excretion and it is classified as pre-hepatic, hepatic and post-hepatic. This study aimed to evaluate and classify different causes of icterus in dogs during post mortem examination. These dogs were examined from 2014 to 2017, using macroscopic and histologic exams as well as ancillary tests. Eighty-three dogs were examined macroscopically and microscopically. They were separated into groups of icterus types: 24 (28.9%) dogs had pre-hepatic icterus, 45 (54.2%) had hepatic, 13 (15.7%) pre-hepatic and hepatic and one (1.2%) had post-hepatic icterus. Many factors were identified as a cause of icterus, including infectious agents (51/83), neoplasms (13/83), hepatic degeneration (11/83), chronic hepatic diseases (6/83), and obstructive causes (1/87). Among the infectious causes, leptospirosis, ehrlichiosis and disorders suggestive of septicemia were diagnosed. Neoplasms associated with icterus were cholangiocarcinoma, hemangiosarcoma and lymphoma. Other causes of icterus included degenerative diseases, such as lipidosis and glycogen degeneration. Hepatic fibrosis (cirrhosis) as a chronic disease and cholelithiasis also produced icterus. PCR was performed to confirm leptospirosis and ehrlichiosis. Samples of total DNA were used to amplify a fragment of a gene from Leptospira interrogans and Ehrlichia canis. In some dogs, co-infection of these agents was detected. The classification and identification of icterus etiologies in dogs is very important due to the number of diseases with this alteration, where ante mortem diagnosis is not always easily performed when some of these conditions are present.

Anatomopathological findings of Testudines necropsied in the Distrito Federal, Brazil

“…In these cases, wild animals may have been rescued and/ or seized by law enforcement agencies or spontaneously surrendered by people. A possible cause for hepatic steatosis in free-living Testudines was reported by Cardells (2012) in his study with Trachemys scripta, in which changes related to icteric or lipidic liver were more expressive in free-living reptiles than that of captive animals, where this condition can be considered of multifactorial origin (bacterial, parasitic and viral agents, metabolic disorders, prolonged fasting, hormonal changes, hibernation, reproductive cycles, inadequate temperatures, neoplasia), since these reports have been found in other reptiles, birds and mammals (Echeto & Aranjibel 1999, Mcarthur et al 2004, Sanches 2008, Osorio & Cañas 2012, Andrade et al 2020). Given the above, the need for further research on the etiopathogeny of diseases in these animals is evident.…”

Icterícia: Da Manifestação Ao Manejo Clínico-Terapêutico

“…Icterícia é uma manifestação clínica caracterizada pela tonalidade amarelada em superfícies corpóreas como: membranas revestidas por mucosas, região escleral e pele (2)(3)(4). A coloração amarela origina-se do excesso na concentração da bilirrubina, na região de tecidos e plasma, caracterizando-a como hiperbilirrubinemia.…”

“…No início do processo, a bilirrubina liga-se a proteínas plasmáticas, especialmente a albumina, tornando-se bilirrubina ligada à albumina (3,9). Pela capacidade de percorrer toda a circulação e fluidos de natureza intersticial, ela é conduzida ao fígado.…”

“…Quadros de icterícia pós-hepática associam-se com situações que promovam obstrução da via de saída hepatobiliar (3,5), principalmente por alterações nas vias biliares de região extra-hepática (represamento do material). Considera-se que as icterícias pós-hepáticas são caracterizadas pela presença das duas formas de bilirrubina, com abundância do tipo conjugada.…”

“…A leptospirose é uma importante zoonose causada por bactérias do gênero Leptospira spp. e proporcionam lesão hepática agudizada com manifestação ictérica (3,26). A PIF causada pelo coronavírus felino também induz a ocorrência de icterícia por vasculites (forma efusiva), induzindo o aumento da permeabilidade vascular e extravasamento de fluidos (27).…”