Viral type characterization and clinical aspects of canine parvovirus in naturally infected dogs in São Paulo State, Brazil

Abstract

Since the first isolation of canine parvovirus type 2 (CPV-2) in late 70's new virus types as CPV-2a and CPV-2b have been emerged and becoming prevalent in natural canine population and more recently, a third subtype was identified , CPV-2c. The main purpose of this study was to detect and characterize canine parvovirus currently present in Central--West region of São Paulo state, in Brazil. Fecal samples were collected of vaccinated and non-vaccinated dogs, clinically suspected of having CPV infection brought to the Infectious Diseases Service, Veterinary Hospital of FMVZ-UNESP. All samples (n=30) were screening for canine parvovirus through hemagglutination test and those resulting as positive (n=20) were submitted to PCR and the products were subsequently sequenced for subtype characterization. Results were tested for association with age, hematological values, viral hemagglutination titers in the feces, vaccination status and survival. Leukopenia was found in all animals, death occurred in 30% of unvaccinated dogs and in 42% of vaccinated ones. In a total of 20 positive sequenced samples, 18 were classified as CPV-2b, one as CPV-2c, and one as CPV-2a, being CPV2a and CPV2c detected in unvaccinated puppies. Compared to the reference samples amino acid change at position 426 in those circling virus was identified. The study results demonstrate the predominance of CPV-2b and the presence of CPV-2a and CPV-2c in naturally infected, vaccinated and unvaccinated dogs in in São Paulo region.INDEX TERMS: Canine parvovirus, PCR, viral type, dogs.

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“…Clinicamente, 20,8% (15/72) apresentavam palidez de mucosas que é indicativo desta alteração. Casos de parvovirose em cães durante o período de vacinação já tinha sido relatado e indicam janela de suscetibilidade dos filhotes, consequência dos baixos níveis de anticorpos maternos e sistema imunológico imaturo, ainda não capaz de responder efetivamente à imunização (Fontana et al, 2013), considerado o principal fator de risco para falha vacinal (Monteiro et al, 2016). Neste caso, 30,7% estavam durante o período inicial de vacinação.…”

“…Os autores sugerem que diferenças na mortalidade podem estar relacionadas à demora dos tutorem em levar os cães para realizarem a terapia no hospital onde a pesquisa foi realizada. As falhas dos tutores em completar o protocolo vacinal, muitas vezes administrando apenas uma ou duas doses do imunizante, também pode ter contribuído para este resultado (Monteiro et al, 2016). Contudo, avaliar a taxa de óbitos entre imunizados e não imunizados não foi o escopo da nossa pesquisa, uma vez que pacientes com diagnóstico positivo para parvovirose no HVU-UFSM são encaminhados para outras clínicas do município, o que dificulta o descobrimento do desfecho dos casos.…”

Haematology and serum biochemistry of dogs naturally infected with canine parvovirus-2

“…Greene (2012), Decaro & Buonavoglia (2012) and Judge (2015) also reported that leucopenia with attendant lymphopaenia and neutropaenia is a common condition in parvoviral enteritis due to the CPV effect on rapidly dividing leukocytic precursor cells of the bone marrow and lymphopoetic damage during the early stage of the infection. Meanwhile, some authors reported neutrophila, lymphocytosis and thrombocytosis in CPV infected dogs, which may be attributed to the stage of infection during the blood collection (Ramprabhuet al 2002;Chakrabarti, 2003;Kalli et al 2010;Monteiro et al, 2016;Kumar & Rajni, 2017;Agnihotri et al, 2017;Kumar & Rajni, 2017;Mohanta et al, 2018). The significant effect of CPV on the infected dogs based on age was supported by the report of Dash et al (2017), who also reported that the haematological effect of CPV was more in puppies than in an adult.…”