Canine distemper virus, atypical Toxoplasma gondii, and Neospora caninum co-infection, in a dog with neurological signs from Argentina

The occurrence of combined infections by Toxoplasma gondii, Neospora caninum and Canine distemper virus (CDV) in domestic dogs and wildlife animals has not been frequently reported, and the histopathological findings were not exhaustively described. The objective of this study was to report a co-infection of CDV, T. gondii and N. caninum in a dog with neurological signs, as well as the molecular characterization of the protozoa involved. A young street dog was rescued with neurological clinical signs and died spontaneously. A complete necropsy was performed. Tissues were collected and fixed for histopathological evaluation. Additionally, sections of the central nervous system (CNS) and heart were assayed by immunohistochemistry (IHQ) for T. gondii and N. caninum. Sample of brain tissue was analyzed by PCR and nPCR-RFLP for T. gondii genotyping. Spleen was used for detection of CDV by RT-PCR. Gross lesions were not observed, with the exception of the lung. Microscopically, a severe necrosuppurative meningoencephalitis with vasculitis, tachyzoites and bradyzoites of T. gondii and N. caninum were found. Demyelination was also evident, associated with eosinophilic intranuclear inclusion bodies within astrocytes. CDV was PCR positive while both parasites were presented PCR and IHQ positive results. Molecular characterization of T. gondii was reported as atypical #14 (likely). To our knowledge, this is the first report of genetical identification of T. gondii obtained from the brain of a naturally infected dog in Argentina. The results emphasize the importance of different techniques as diagnostic tools to enhance the detection of causative agents in cases of fatal encephalitis.

Canine distemper virus, atypical Toxoplasma gondii, and Neospora caninum co-infection, in a dog with neurological signs from Argentina

The occurrence of combined infections by Toxoplasma gondii, Neospora caninum and Canine distemper virus (CDV) in domestic dogs and wildlife animals has not been frequently reported, and the histopathological findings were not exhaustively described. The objective of this study was to report a co-infection of CDV, T. gondii and N. caninum in a dog with neurological signs, as well as the molecular characterization of the protozoa involved. A young street dog was rescued with neurological clinical signs and died spontaneously. A complete necropsy was performed. Tissues were collected and fixed for histopathological evaluation. Additionally, sections of the central nervous system (CNS) and heart were assayed by immunohistochemistry (IHQ) for T. gondii and N. caninum. Sample of brain tissue was analyzed by PCR and nPCR-RFLP for T. gondii genotyping. Spleen was used for detection of CDV by RT-PCR. Gross lesions were not observed, with the exception of the lung. Microscopically, a severe necrosuppurative meningoencephalitis with vasculitis, tachyzoites and bradyzoites of T. gondii and N. caninum were found. Demyelination was also evident, associated with eosinophilic intranuclear inclusion bodies within astrocytes. CDV was PCR positive while both parasites were presented PCR and IHQ positive results. Molecular characterization of T. gondii was reported as atypical #14 (likely). To our knowledge, this is the first report of genetical identification of T. gondii obtained from the brain of a naturally infected dog in Argentina. The results emphasize the importance of different techniques as diagnostic tools to enhance the detection of causative agents in cases of fatal encephalitis.(AU)

Diagnostic value of copper parameters to predict growth of suckling calves grazing native range in Argentina / Valor diagnóstico dos parâmetros de cobre para prever o crescimento de bezerros lactantes em pastagem nativas na Argentina

A study was conducted to evaluate the predictive diagnostic value of different copper (Cu) parameters as indicators of average daily gain (ADG) in growing calves. The effects in calves of cow Cu supplementation in the last one-third gestation period were also evaluated. Five supplementation trials, with a total of 300 calves, were carried out. Two groups of 30 calves were randomly assigned to each trial, one group was parenterally supplemented (SG) and the other was not supplemented (NSG). Trials began when calves were three-month-old and ended at weaning time. At each sampling calves were weighed and blood was taken to determine Cu concentrations in plasma, Whole Blood (WB), Red Cells (RC) and Packed Cell Volume (PCV). Liver samples from six animals of each group were taken both at the beginning and at the end of the trial. In two trials the mothers of the SG received Cu supplementation at the last one- third gestation period. Four of the five trials exhibited low ADG in the NSGs. In these groups, plasma Cu concentration decreased rapidly before low ADG was detected, which occurred with values remaining below 25µg/dl. The decrease of RC Cu concentration was considerably slow. WB showed an intermediate position. PCV in the SGs was higher than in the NSGs in all trials. Cow supplementation was insufficient to generate a liver storage able to last after calves reached the 3 months of age. These data could be useful to predict the risk of low ADG in grazing calves.(AU)

Foi realizado um estudo para predisser o valor diagnóstico de diferentes parâmetros de cobre (Cu) como indicadores de ganho médio diário (ADG) na criação de bezerros. Também foram avaliados os efeitos da suplementação com Cu nas vacas no último terço da gestação. Cinco ensaios de suplementação, com um total de 300 bezerros, foram realizados. Dois grupos de 30 bezerros foram atribuídos aleatoriamente em cada proba, um grupo foi parenteralmente suple mentado (SG) e o outro não foi suplementado (NSG). Os ensaios começaram quando os bezerros tinham três meses de idade e terminou ao tempo do destete. Em cada ensaio os bezerros foram pesados e mostras do sangue foi tomada para determinar as concentrações Cu no plasma, sangue total (WB), eritrócitos (RC) e hematócrito (PCV). Amostras de fígado foram colhidas em seis animais de cada grupo tanto no início quanto no final do ensaio As mães do SG receberam suplementação de Cu no último terço da gestação em dois ensaios. Quatro dos cinco ensaios apresentavam baixa ADG nos NSGs. Nesses grupos, a concentração plasmática de Cu diminuiu rapidamente antes que a baixa do ADG fossei detectada, o que ocorreu com os valores abaixo 25 µg/d. A diminuição da concentração de RC Cu foi bastante lenta. WB mostrou uma posição intermédia. PCV nos SGs foi mais elevado do que nos NSGs em todos os ensaios. A suplementação das vacas foi insuficiente para gerar um armazenamento hepático capaz de durar até os 3 meses de idade dos bezerros. Estes dados poderiam ser úteis para prever o risco de baixa ADG em bezerros em pastagem.(AU)