Canid herpesvirus 1 Preferentially Infects Polarized Madin-Darby Canine Kidney Cells from the Basolateral Surface.

Canid herpesvirus 1 (CHV-1) infects polarized canine epithelia. Herein, we present our initial work characterizing CHV-1 infection of Madin-Darby canine kidney (MDCK) cells that were polarized on trans-wells. We previously showed that infection of these cells in non-polarized cultures stimulated the formation of extensive lamellipodial membrane protrusions. Uninfected polarized MDCK cells already form extensive lamellipodial membrane protrusions on the apical surface in the absence of virus. Using scanning electron microscopy, we found that CHV-1 infection does not lead to a change in the form of the lamellipodial membrane protrusions on the apical surface of polarized MDCK cells. We found that CHV-1 was able to infect polarized cultures from either the apical or basolateral side; however, higher viral titers were produced upon infection of the basolateral side. Regardless of the side infected, titers of virus were higher in the apical compartment compared to the basal compartment; however, these differences were not statistically significant. In addition to cell-free virus that was recovered in the media, the highest amount of virus produced remained cell-associated over the course of the experiment. The efficiency of CHV-1 infection of the basolateral side of polarized epithelial cells is consistent with the pathobiology of this varicellovirus.

Canid herpesvirus 1 (CHV-1)-related disease in older puppies and CHV-1 shedding in the vagina of adult pregnant dogs.

A large breeding kennel of Bulldogs (n = 57) experienced several Canid herpesvirus 1 (CHV-1)-related diseases in older puppies (9 weeks of age) in Arkansas. CHV-1 has been repeatedly confirmed in the kennel in several animals for 3 years (January 2012-February 2015) using various virology tests. I was able to detect a partial sequence of CHV DNA (~120 bp) in archived formalin-fixed, paraffin-embedded tissue blocks after 3 years of storage. CHV-1 is persistently circulating in this kennel in spite of high serum antibody titers in the adult dogs. The dogs were negative for canine brucellosis antibodies based on Brucella canis rapid card test.

Outbreaks of canid herpesvirus 1 disease in puppies in southern Brazil / Surtos de doença por herpesvírus canino 1 em filhotes de cães no sul do Brasil

Canid herpesvirus 1 (CHV-1) is a widespread pathogen of dogs and produces infertility, abortions and severe systemic disease in young puppies. Clinical data indicate the circulation of CHV-1 among Brazilian dogs yet definitive diagnosis has rarely been accomplished. This article describes the clinicopathological findings of four independent cases/outbreaks of neonatal disease by CHV-1 in Bulldog puppies followed by virus identification and genetic characterization. Three events occurred in a kennel holding dogs of different breeds at reproductive age (March 2013, October 2013 and April 2014). Puppies from three French or English Bulldog litters, aging 9 to 30 days were affected, presenting dyspnea, agonic breathing, pale mucous, abdominal pain and tension, evolving to death within about 24 hours. At necropsy, the puppies presented necrohemorrhagic hepatitis, multifocal and moderate necrohemorrhagic nephritis and fibrinonecrotic interstitial pneumonia. Virus isolation was positive in clinical specimens from one litter and CHV-1 DNA was detected by PCR in tissues from all four cases. Virus-neutralizing assays with samples of the affected kennel revealed 9/12 adult animals with high antibody titers to CHV-1. Nucleotide sequencing of glycoprotein B, C and D genes revealed 99-100% of identity among the viruses and with CHV-1 sequences available in GenBank. Phylogenetic analyses of gC sequences showed a segregation of the samples, even among three isolates from the same kennel. These findings support CHV-1 infection as the cause of disease and death in these dog litters, reinforcing the need for correct etiologic diagnosis, prevention and immunization against CHV-1 in dogs from Southern Brazil.

O herpesvírus canino (CHV-1) é um patógeno de cães que possui distribuição mundial e que causa infertilidade, abortos e doença sistêmica severa em filhotes de cães. Achados clínicos tem indicado a circulação do CHV-1 em cães no Brasil, embora o diagnóstico definitivo seja raramente determinado. Este artigo descreve os achados clinicopatológicos de quatro casos/surtos independentes de morte neonatal de filhotes de cães da raça Bulldog causados pelo CHV-1, a identificação e a caracterização genética do vírus. Três eventos ocorreram no mesmo canil que abriga animais de diferentes raças em idade reprodutiva (março de 2013, outubro de 2013 e abril de 2014). Filhotes de três ninhadas de Bulldog Francês e/ou Inglês, com idade de 9 a 30 dias, foram afetados e apresentaram dispneia, respiração agônica, mucosas pálidas, dor e tensão abdominal, que evoluíram para morte dos cães dentro de, aproximadamente, 24 horas. Na necropsia foram observados hepatite necro-hemorrágica, nefrite necro-hemorrágica multifocal e moderada e pneumonia intersticial fibrinonecrótica. O isolamento viral foi positivo em amostras clínicas de um filhote e DNA de CHV-1 foi detectado por PCR em tecidos de filhotes de todos os surtos. Teste de soroneutralização com amostras de soro de cães provenientes do canil afetado revelaram que nove de 12 animais adultos possuíam altos títulos de anticorpos para o CHV-1. Sequenciamento de nucleotídeos do gene das glicoproteínas B, C e D revelaram 99-100% de identidade entre as amostras e com as sequências de CHV-1 disponíveis no GenBank. A análise filogenética baseada na sequência do gene da glicoproteína C mostrou uma segregação das amostras, mesmo entre os três isolados de vírus provenientes do mesmo canil. Esses achados demonstram que o CHV-1 é a causa da doença e da morte dos filhotes, reforçando a necessidade do correto diagnóstico etiológico e a implementação de medidas de prevenção e imunização contra o CHV-1 em cães no sul do Brasil.

Fatal Canid Herpesvirus 1 Respiratory Infections in 4 Clinically Healthy Adult Dogs.

Four healthy adult dogs (Golden Retrievers aged 6 years and 9 years, Dalmatian aged 13 years, and Mastiff aged 5 years) developed clinical signs of acute respiratory disease and died within 2 to 7 days of onset of clinical signs. The lungs of the 3 dogs submitted for necropsy were diffusely and severely reddened due to hyperemia and hemorrhage. Microscopic lesions in all dogs were suggestive of acute viral or toxic respiratory damage and varied from acute severe fibrinonecrotic or hemorrhagic bronchopneumonia to fibrinous or necrotizing bronchointerstitial pneumonia. Necropsied dogs also had hemorrhagic rhinitis and tracheitis with necrosis. Virus isolation, transmission electron microscopy, and polymerase chain reaction were used to confirm the presence of canid herpesvirus 1 (CaHV-1) in the lung samples of these dogs. Lung tissues were negative for influenza A virus, canine distemper virus, canine parainfluenza virus, canine respiratory coronavirus, and canine adenovirus 2. Canid herpesvirus 1 has been isolated from cases of acute infectious respiratory disease in dogs but has only rarely been associated with fatal primary viral pneumonia in adult dogs. The cases in the current report document lesions observed in association with CaHV-1 in 4 cases of fatal canine herpesvirus pneumonia in adult dogs.