Feline herpesvirus 1 viral load related to environmental factors in sheltered cats / Relação entre carga viral de herpesvirus felino 1 e fatores causadores de estresse em felinos de abrigo

ABSTRACT: Shelter environment stress factors are related to FHV-1 viral reactivation. However, comparisons between conjunctival viral load and environmental factors have not been commonly evaluated. The aim of this study was to correlate FHV-1 viral load in domestic cats with and without clinical signs of conjunctivitis to shelter design in order to use FHV-1 viral load as a parameter of "health management". Cats from four different shelters underwent an ophthalmological examination. Samples were collected by rolling a DNA/RNAse-free cytobrush over the ventral conjunctival fornix and were stored in 1.5 mL sterile microtubes in 500 μL of Eagle's minimum essential medium and kept at 4 ºC. Molecular procedures were performed up to 48 hours after collection. Different routines regarding new arrivals were directly related to FHV-1 viral load. Shelters where new arrivals occurred on daily basis had the highest viral load (2.69x108 copies/µL), while those shelters where new arrivals had not occurred in the few months prior to the beginning of the study had the lowest rate (1.63x103 copies/µL). Environmental factors directly influenced FHV-1 DNA viral load. This study highlighted the need to improve the management approach in the animal shelter environment to reduce stressful situations responsible for FHV-1 reactivation and higher viral load quantification.

RESUMO: No ambiente do abrigo encontram-se fatores que geram estresse nos animais que ali residem. Esses fatores acabam por provocar a reativação do FHV-1. No entanto, comparações entre carga viral conjuntival e fatores ambientais não foram ainda avaliadas. Objetivo deste estudo foi correlacionar a carga viral de FHV-1 em felinos domésticos com e sem sinais clínicos de conjuntivite com as características dos abrigos. Assim, pode-se usar carga viral de FHV-1 como parâmetro de sanidade. Todos os gatos foram submetidos a exame clínico oftalmológico. Amostras foram coletadas com uso de escova citológica, acondicionadas em microtubos estéreis de 1,5mL contendo 500 μL de meio Eagle essencial mínimo e mantidas em 4 ºC. Análises moleculares foram realizadas no prazo de 48 horas após coleta. A rotina de entrada de novos animais estava diretamente relacionada a carga viral de FHV-1. Abrigos com entrada diária apresentaram carga viral maior (2.69x108 cópias/µL), do que abrigo onde novos animais não chegaram nos meses que antecederam a coleta (1.63x103 cópias/µL). Fatores ambientais influenciam diretamente carga viral de FHV-1. Esse estudo evidencia a necessidade de aprimorar o sistema de manejo dos abrigos de forma a reduzir situações de estresse responsáveis pela reativação de FHV-1 e consequente aumento na carga viral.

Molecular characterization of feline calicivirus variants from multicat household and public animal shelter in Rio de Janeiro, Brazil

ABSTRACT The aim of this study was to perform the molecular characterization of conserved and variable regions of feline calicivirus capsid genome in order to investigate the molecular diversity of variants in Brazilian cat population. Twenty-six conjunctival samples from cats living in five public short-term animal shelters and three multicat life-long households were analyzed. Fifteen cats had conjunctivitis, three had oral ulceration, eight had respiratory signs (cough, sneeze and nasal discharge) and nine were asymptomatic. Feline calicivirus were isolated in CRFK cells and characterized by reverse transcription PCR target to both conserved and variable regions of open reading frame 2. The amplicons obtained were sequenced. A phylogenetic analysis along with most of the prototypes available in GenBank database and an amino acid analysis were performed. Phylogenetic analysis based on both conserved and variable region revealed two clusters with an aLTR value of 1.00 and 0.98 respectively and the variants from this study belong to feline calicivirus genogroup I. No association between geographical distribution and/or clinical signs and clustering in phylogenetic tree was observed. The variants circulating in public short-term animal shelter demonstrated a high variability because of the relatively rapid turnover of carrier cats constantly introduced of multiple viruses into this location over time.

Behavior of red cell distribution width (RDW) in a population of anemic and non-anemic dogs from an ambulatory care unit

O objetivo deste estudo foi avaliar o comportamento do índice de anisocitose na interpretação do hemograma de cães anêmicos e não anêmicos. Atualmente, contadores hematológicos automatizados veterinários fornecem alguns índices que não são calculados quando o hemograma é confeccionado manualmente. A saber: RDW-CV (Amplitude de distribuição de hemácias como coeficiente de variação) e RDW-SD (Amplitude de distribuição de hemácias como desvio-padrão). Tais índices levaram a uma nova abordagem do paciente com anemia permitindo que a anisocitose fosse mensurada de uma forma quantitativa. Foram avaliados 454 hemogramas processados no período de setembro de 2009 a março de 2011. Foram calculados média e desvio padrão e uma análise de variância foi realizada. Os cães anêmicos (125/454) apresentaram altos valores de RDW enquanto que, em animais não anêmicos, esse índice permaneceu dentro dos valores de normalidade previamente estabelecidos. O índice também estava alto em animais com anisocitose observada à microscopia. Houve uma diferença significante entre os índices dos animais que apresentaram Volume Globular Médio (VGM) elevado e normal. Concluiu-se que os índices RDW-CV e RDW-SD foram sensíveis a pequenas variações no tamanho das hemácias e na heterogeneidade, sendo mais precisos que a observação microscópica para se detectar anisocitose e mais sensível que VGM para variação eritrocitária.

The aim of this study was to evaluate the behavior of the red cell distribution width (RDW) in the interpretation of the Complete Blood Count (CBC) from anemic and non-anemic dogs. Currently, automated veterinary blood cell analyzers provide hematologic indices not calculated in manually performed CBC, such as Red Blood Cell Distribution Width measured by Variation Coefficients (RDW-CV) and Red Blood Cell Distribution Width measured by Standard Deviation (RDW-SD), which has led to new of September 2009 to March 2011. Mean and standard deviation were calculated and variance analysis was performed. Anemic dogs (125/454) presented higher values for RDW indices. In non-anemic animals, these indices were in accordance with the normal values previously established. Both indices were higher in dogs with microscopic observation of anisocytosis. There was a significant difference among índices of the animals which showed normal and increased Mean Corpuscular Volume (MCV). We concluded that RDW-CV and RDW-SD indices were sensitive to small variations on erythrocyte size and heterogeneity, being more accurate than microscopic observations to detect anisocytosis and more sensitive than MCV to erythrocyte variation.