Identification of enteric viruses circulating in a dog population with low vaccine coverage

ABSTRACT Although the use of vaccines has controlled enteric diseases in dogs in many developed countries, vaccine coverage is still under optimal situation in Brazil. There is a large population of nonimmunized dogs and few studies about the identification of the viruses associated with diarrhea. To address this situation, stool samples from 325 dogs were analyzed by polymerase chain reaction for the detection of common enteric viruses such as Canine adenovirus (CAdV), Canine coronavirus (CCoV), Canine distemper virus (CDV), Canine rotavirus (CRV) and Carnivorous protoparvovirus 1 (canine parvovirus 2; CPV-2). At least one of these species was detected in 56.6% (184/325) of the samples. The viruses detected most frequently in either diarrheic or nondiarrheic dog feces were CPV-2 (54.3% of the positive samples), CDV (45.1%) and CCoV (30.4%), followed by CRV (8.2%) and CAdV (4.9%). Only one agent was detected in the majority of the positive samples (63%), but co-infections were present in 37% of the positive samples and mainly included CDV and CPV-2. The data presented herein can improve the clinical knowledge in regions with low vaccine coverage and highlight the need to improve the methods used to control these infectious diseases in domestic dogs.

Detection and genetic characterization of Mamastrovirus 5 from Brazilian dogs

Abstract Mamastrovirus 5 (MAstV5), belonging to the Astroviridae (AstV) family, previously known as canine astrovirus or astrovirus-like particles, has been reported in several countries to be associated with viral enteric disease in dogs since the 1980s. Astroviruses have been detected in fecal samples from a wide variety of mammals and birds that are associated with gastroenteritis and extra enteric manifestations. In the present study, RT-PCR was used to investigate the presence of MAstV5 in 269 dog fecal samples. MAstV5 was detected in 26% (71/269) of the samples. Interestingly, all MAstV5-positive samples derived from dogs displaying clinical signs suggestive of gastroenteritis, other enteric viruses were simultaneously detected (canine parvovirus, canine distemper virus, canine coronavirus, canine adenovirus and canine rotavirus). Based on genomic sequence analysis of MAstV5 a novel classification of the species into four genotypes, MAstV5a-MAstV5d, is proposed. Phylogenetic analyses based on the ORF2 amino acid sequences, samples described herein grouped into the putative genotype 'a' closed related with Chinese samples. Other studies are required to attempt the clinical and antigenic implications of these astrovirus genotypes in dogs.

Identification of co-infection by rotavirus and parvovirus in dogs with gastroenteritis in Mexico

ABSTRACT This is the first report on circulating canine rotavirus in Mexico. Fifty samples from dogs with gastroenteritis were analyzed used polymerase chain reaction and reverse transcription polymerase chain reaction in order to identify parvovirus and rotavirus, respectively; 7% of dogs were infected with rotavirus exclusively, while 14% were co-infected with both rotavirus and parvovirus; clinical signs in co-infected dogs were more severe.

Detection of respiratory viruses in shelter dogs maintained under varying environmental conditions

Abstract Three dog shelters in Rio Grande do Sul were investigated for associations between the occurrence of respiratory viruses and shelter environmental conditions. Nasal secretions randomly collected during the cold season were tested via PCR, and this data collection was followed by nucleotide sequencing of the amplicons. In shelter #1 (poor sanitary and nutritional conditions, high animal density and constant contact between dogs), 78% (58/74) of the nasal samples were positive, 35% (26/74) of which were in single infections and 44% (32/74) of which were in coinfections. Shelters #2 and #3 had satisfactory sanitary and nutritional conditions, outdoors exercise areas (#2) and animal clustering by groups (#3). In shelter #2, 9% (3/35) of the samples were positive for Canine parainfluenza virus (CPIV), and 6% (2/35) were positive for Canid herpesvirus 1 (CaHV-1). In shelter #3, 9% (7/77) of the samples were positive for Canine adenovirus type 2 (CAdV-2), and 1% (1/77) were positive for Canine distemper virus (CDV). The amplicon sequences (CPIV and CDV nucleoprotein gene; CAdV-2 E3 gene; CaHV-1 glycoprotein B gene) showed 94-100% nucleotide identity with GenBank sequences. Our results demonstrate that CPIV, CAdV-2 and CDV are common in dog shelters and that their frequencies appear to be related with environmental and nutritional conditions. These results indicate the need for control/prevention measures, including vaccination and environmental management, to minimize these infections and improve dog health.

Influenza viruses in adult dogs raised in rural and urban areas in the state of São Paulo, Brazil / Incidência do vírus influenza em cães adultos criados em áreas rural e urbana do estado de São Paulo, Brasil

In 1970, searching for the interspecies transmission of influenza viruses led to the first study on influenza viruses in domestic animals. Birds and mammals, including human beings, are their natural hosts; however, other animals may also play a role in the virus epidemiology. The objective was to investigate the incidence of influenza viruses in adult dogs raised in rural (9, 19.56%) and urban (37, 80.43%) areas in the state of São Paulo, Brazil. Dog serum samples were examined for antibodies to influenza viruses by the hemagglutination inhibition (HI) test using the corresponding antigens from the circulating viruses in Brazil. Dogs from rural areas presented antibodies to influenza A H3N2, and influenza A H7N7 and H3N8. In rural areas, dog sera displayed mean titers as 94.37, 227.88, 168.14, 189.62 HIU/25 µL for subtypes H1N1, H3N2, H7N7, H3N8, respectively. About 84% and 92% of dogs from urban areas exhibited antibodies to human influenza A H1N1 and H3N2, respectively, with statistical difference at p < 0.05 between the mean titers of antibodies to H1N1 and H3N2. About 92% and 100% were positive for H7N7 and H3N8, respectively. In dogs from urban areas, the mean titers of antibodies against influenza A H1N1, H3N2, H7N7 and H3N8, were 213.96, 179.42, 231.76, 231.35 HIU/25 µL respectively. The difference among them was not statistically significant at p > 0.05. In conclusion, these dogs were positive for both human and equine influenza viruses. The present study suggests the first evidence that influenza viruses circulate among dogs in Brazil.

A transmissão interespecífica do vírus influenza é relatada em estudo sobre influenza com animais domésticos desde 1970. Pássaros e mamíferos, incluindo o homem, são seus hospedeiros naturais, porém outros animais podem participar da sua epidemiologia. Foi investigada a incidência do vírus influenza em cães adultos criados em zonas rural (9, 19,56%) e urbana (37, 80,43%), do Estado de São Paulo. Os soros dos cães foram examinados pelo teste de inibição da hemaglutinação (IH), usando antígeno dos vírus influenza circulantes no Brasil. Nos cães rurais foram detectados títulos médios de 94,37, 227,88, 168,14 e 189,62 UIH/25 mL (unidades inibidoras de hemaglutinação/25 mL) para os subtipos H1N1, H3N2, H7N7, H3N8 de vírus influenza A, respectivamente, com diferenças estatisticamente significativas (p<0,05) entre as médias de títulos de anticorpos contra H1N1 e H3N2. Cerca de 84% e 92% dos cães urbanos responderam aos vírus influenza A humano H1N1 e H3N2, respectivamente e destes 92% e 100% foram positivos para os vírus eqüinos H7N7 e H3N8, respectivamente. Para esses cães as médias de títulos de anticorpos para os vírus influenza A H1N1, H3N2, H7N7 e H3N8 foram 213,96, 179,42, 231,76 e 231,35UIH/25 mL, respectivamente. As diferenças entre as médias não foram estatisticamente significativas (p>0,05). Conclui-se que os cães apresentaram positividade para ambos vírus influenza humano e equino. O presente estudo sugere, pela primeira vez, evidências de que há circulação do vírus influenza em cães, no Brasil.