Canine distemper virus (CDV) is a major pathogen of dogs and represents a serious threat to both unvaccinated and vaccinated animals. This study surveyed dogs with or without clinical signs related to canine distemper from different regions of Brazil from 2008 to 2012. A total of 155 out of 386 animals were found to be CDV positive by RT-PCR; 37 (23.8%) dogs were asymptomatic at the time of sampling, and 90 (58%) displayed clinical signs suggestive of distemper. Nineteen (12.2%) dogs had a record of complete vaccination, 15 (9.6%) had an incomplete vaccination protocol, and 76 (49%) had no vaccination record. Based on the sequence analysis of the complete hemagglutinin gene of 13 samples, 12 of the strains were characterized as Genotype South America-I/Europe. Considering criteria of at least 95% nucleotide identity to define a genotype and 98% to define a subgenotype, South America-I/Europe sequences segregated into eight different phylogenetically well-defined clusters that circulated or co-circulated in distinct geographical areas. Together, these findings highlight the relevance of CDV infection in Brazilian dogs, demonstrate the predominance of one genotype in Brazil and support the need to intensify the current control measures.

Detection and characterisation of the canine parvovirus (CPV-2) strains that are currently circulating are essential for the understanding of viral evolution and the development of measures to control its spread. In the present study, stool samples from 144 dogs were analysed by polymerase chain reaction (PCR) for CPV-2, and 29.2% (42/144) of them were positive. From the 42 positive strains, 71.4% (30) of the dogs had signs of haemorrhagic gastroenteritis. The sequencing of the 583 bp fragment of the VP2 gene from the positive strains identified 78.6% (33/42) of them as type 2c, 19% (8/42) as type 2b and 2.4% (1/42) as type 2a. A phylogenetic analysis of the variants circulating in the canine population of Brazil showed that they are very similar to those found in other countries and type 2c has become the predominant type circulating in Brazil.

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.

Characterization of canine coronavirus (CCoV) strains currently in circulation is essential for understanding viral evolution. The aim of this study was to determine the presence of pantropic CCoV type IIa in tissue samples from five puppies that died in Southern Brazil as a result of severe gastroenteritis. Reverse-transcriptase PCR was used to generate amplicons for sequence analysis. Phylogenetic analysis of the CCoV-IIa strains indicated that they were similar to those found in other countries, suggesting a common ancestor of these Brazilian isolates. This is the first report of pantropic CCoV-II in puppies from Latin America and our findings highlight that CCoV should be included as a differential diagnosis when dogs present with clinical signs and lesions typically seen with canine parvovirus infection.

No abstract