Relationship between clinical and pathological signs and severity of canine leishmaniasis

Abstract

Canine visceral leishmaniasis (CVL) is a zoonotic disease that presents variable clinical and laboratory aspects. The aims of this study were to identify the main biochemical/hematological status of dogs naturally infected with Leishmania (Leishmania) infantum and to associate theses parameters with clinical forms of CVL. Blood samples were analyzed from 51 dogs, 15 uninfected (control group) and 36 infected, which were classified clinically in three groups: asymptomatic (n=12), oligosymptomatic (n=12) and symptomatic (n=12). All the infected dogs showed lower albumin/ globulin ratios (A-G ratio) than the limit of reference. The mean values of total protein, urea, α-globulin 2, globulin and A-G ratio of infected dogs were outside the reference interval and differed significantly from those of the controls. Anemia was detected only in groups that showed clinical signs of the disease, and a statistical analysis indicated a significantly higher frequency of lower eritrogram in these groups than in the asymptomatic group. In addition, a significant association was observed between anemia and the presence of the symptoms, with dogs displaying higher erythrogram values showing better clinical conditions. These results provide additional evidence that the clinical forms of CVL may reflect on the erythrogram status.Keywords: Canine visceral leishmaniasis, clinical forms, laboratory findings, anaemia, relationship. ResumoA leishmaniose visceral canina (LVC) é uma zoonose com aspectos clínicos e laboratoriais variáveis. O objetivo deste trabalho foi identificar os principais achados hematológicos e bioquímicos em cães naturalmente infectados com Leishmania (Leishmania) infantum e associar esses parâmetros com as formas clínicas da LVC. Foram analizadas amostras sanguíneas provenientes de 51 cães, sendo 15 cães não infectados (grupo controle) e 36 infectados, os quais foram classificados clinicamente em três grupos: assintomáticos (n=12), oligossintomáticos (n=12) e sintomáticos (n=12). Todos os cães infectados apresentaram valores na relação albumina/globulina (A/G) abaixo do limite inferior de referência. Os valores médios de proteína total, uréia, α-2 globulina, globulina e A/G dos grupos de cães infectados permaneceram fora dos intervalos de referências e significativamente diferente quando comparados aos do grupo controle. Anemia foi registrada somente nos grupos de animais que manifestavam sinais clínicos da enfermidade, sendo que nas análises estatísticas constatou-se frequencia significativamente maior de alterações no eritrograma quando comparados ao grupo assintomático. Associação significativa foi observada entre anemia e a presença de sinais clínicos, onde os cães com os maiores valores de eritrograma apresentavam a melhor condição clínica. Os resultados fornecem evidência adicional que as formas clínicas da LVC podem refletir no eritrograma.Palavras-chave: Leishmaniose visceral canina, formas clínicas, achados laboratoriais, anemia, relação.

Laboratory tests for diagnosing and monitoring canine leishmaniasis

“…This approach is based on a thorough clinical evaluation including the measurement of arterial pressure, and on the quantification of urinary proteins and of markers of renal function such as the urine specific gravity and the serum concentration of creatinine . This latter increases frequently in leishmaniotic dogs . However, creatinine is not sensitive enough to detect the earliest stages of renal insufficiency, and research is currently underway to identify early markers for decreased glomerular filtration rate (GFR), either in leishmaniotic dogs or in dogs affected by other types of CKD.…”

“…Serum protein analysis including electrophoresis may reveal abnormalities very early during the course of the disease . For instance, total proteins and total globulins are frequently increased, and the increase of total proteins has been shown to correlate with the severity of the clinical score . The only exception is albumin, which decreases because it is a negative APP (see below) but can also be lost due to proteinuric nephropathy, resulting in a decreased albumin‐to‐globulin (A/G) ratio .…”

“…For instance, total proteins and total globulins are frequently increased, and the increase of total proteins has been shown to correlate with the severity of the clinical score . The only exception is albumin, which decreases because it is a negative APP (see below) but can also be lost due to proteinuric nephropathy, resulting in a decreased albumin‐to‐globulin (A/G) ratio . The decrease of the A/G ratio is so frequent that it has been considered by some authors to be one of the most sensitive tests for canine leishmaniasis, and hypoalbuminemia is considered a negative prognostic factor in leishmaniotic dogs .…”

Diagnostic value of neutrophil–lymphocyte and albumin–globulin ratios in canine soft tissue sarcoma

“…Examples of such markers include a decreased albumin-toglobulin ratio (AGR), which has proven useful in aiding the diagnosis of both canine and feline conditions (Hartmann et al . 2003, Ribeiro et al . 2013 ).…”

Scoring clinical signs can help diagnose canine visceral leishmaniasis in a highly endemic area in Brazil

“…Many studies have shown that the clinical signs of infected dogs are related to haematological and biochemical alterations as well as to antibody titres, parasite load, and infectivity to the sand fly vector (da Costa-Val et al 2007, Manna et al 2009, de Freitas et al 2012, Manzillo et al 2013, Ribeiro et al 2013). …”