Canine adenoviruses and herpesvirus

Development of one-step multiplex real-time PCR for the detection of CHV-1, CAdV-2, and CDV

Canine Infectious Respiratory Disease Complex (CIRDC) is a highly contagious disease that frequently affects canine populations and has emerged as a global epidemic. It has been reported that CIRDC can have a serious impact on related life. Therefore, the rapid detection and differentiation of common viruses that cause CIRDC are essential. It is generally believed that CIRDC is mainly caused by infection of three pathogens: canine herpesvirus-1 (CHV-1), canine adenovirus-2 (CAdV-2), and canine distemper virus (CDV). In this study, we developed and validated a TaqMan probe-based multiplex real-time PCR method to detect and identify these three viruses simultaneously. We designed specific primers and probes, and optimized the concentrations of each reactant in the system. The method was found to have good sensitivity, specificity and stability, and had a limit of detection of 102 copies/μL, 101 copies/μL and 101 copies/μL for CHV-1, CAdV-2, and CDV, respectively. In addition, co-infection simulation experiments confirmed that the method worked effectively, even if the concentrations of multiple viruses in the sample were close to the limit of detection or the concentrations of different viruses were different. The method was used to detect 122 clinical samples, and the results showed that it was more sensitive and reliable than conventional singleplex PCR. Thus, the method developed in this study is suitable for the clinical monitoring of CIRDC and is of great significance for the prevention and management of respiratory diseases in canine populations.

Canine Adenoviruses in Wildlife: Role in At-Risk Species Conservation and Interface with Domestic Animals

Canine adenovirus type 1 (CAdV-1) and type 2 (CAdV-2) are well known pathogens of domestic dogs but are little investigated in wild animals. The few available studies about CAdV-1 in wild animals show that it circulates in various species and that transmission of the virus in the interface between wildlife and domestic animals is a frequent event. Furthermore, wild animals are usually subject to asymptomatic infections, but cases of serious and fatal diseases have been documented, with possible effects on the conservation of the species. In contrast, CAdV-2 infection was reported only recently and sporadically in some wild animals, with few data regarding its pathogenic role in these species. However, the real prevalence of these viruses in wildlife is still uncertain due to the use of serological tests that are largely unable to distinguish antibodies against CAdV-1 and CAdV-2. This review, reporting all the data currently available on CAdV-1 and CAdV-2 infection in wild animals, highlights the importance of these pathogens for wildlife conservation and their role in the potential transmission of the infection to domestic dogs.

"My Bitch Is Empty!" An Overview of the Reasons for Pregnancy Loss in Dogs

The purpose of this review is to present reasons for pregnancy loss in dogs. Termination of pregnancy can occur at any stage of gestation, sometimes even before pregnancy is diagnosed. If embryonic death occurs before day 35 of gestation, the embryo is absorbed. Fetal death in the second half of gestation leads to abortion or fetal emphysema, maceration, or mummification. Abnormal embryonic development, competition between placental sites, or genetic abnormalities of the embryo(s) can lead to termination of pregnancy. Maternal factors that alter ovarian function or the environment in the oviducts and uterus, such as cystic endometrial hyperplasia or inflammation, can lead to pregnancy loss. Abnormalities of the placenta, uterine torsion, metrocoele, environmental stress, and malnutrition can have detrimental effects on fetal development. Several drugs or medications can also have embryotoxic/teratogenic effect. Endocrinological disorders such as hypoluteodism, gestational diabetes, and hypothyroidism can be reasons for pregnancy failure. Several bacteria, protozoa, and viruses can cause pregnancy loss in dogs. Etiological diagnoses of pregnancy loss in dogs are challenging as the exact causes are not always obvious; so, a multi-faceted approach is required.

Complete Genome Characterization of Canine Adenovirus From Türkiye With Next-Generation Sequencing

BACKGROUND

Determining the complete genome sequence data of adenoviruses has recently become greatly important due to their use by scientists as vectors in cancer studies and other fields, including vaccine development. However, the GenBank database currently has few complete genome sequences of adenoviruses, which are known for their large genomes. To address this gap, we analysed next-generation sequencing data obtained from our previous study to provide the complete genome sequence of the canine adenovirus-2 strain.

METHODS

For the obtained canine adenovirus-2 strain (OQ596341), comparative genomics, recombination and phylogenetic analysis were conducted. This sequence was compared and phylogenetically analysed with the 20 complete genome sequences of canine adenovirus previously reported in GenBank worldwide, as well as partial E3 ORFA sequences obtained from Türkiye.

RESULTS

The nucleotide similarity rates of the sequence obtained from this study with other CAdV-2 whole genomes are over 99.04%. The gene alignment results reveal that the OQ596341 was found to be closely related to the AC000020 reference genome and LC557011. There are two recombination events related to the genome in this study. Comparisons with other complete genome sequences revealed several previously unseen mutations. These mutations include H34Y in the E1A gene; P55A in the E1B 55K gene; D13N and D202N in the IVa2 gene; K679R, V934I and K989N in the Pol gene; E205K in the pTP gene; T455A in the pIIIa gene; A310V in the V gene; G151R in the protease gene; E268K in the 100K gene; G66S and G141S in the 33K gene; T14A, E250K, D287N and I293T in the E3 ORFA gene; and L193F in the E434K gene. Moreover, a comparison with partial sequences obtained from Türkiye revealed the E250K mutation in the E3 ORFA gene, which we report for the first time in Türkiye.

CONCLUSIONS

The complete CAdV-2 genome sequence obtained in the present study is the first sequence from Europe. Comparative analysis with other genomes revealed some unique mutations. This study is the first to report the E250K amino acid change in the E3 ORFA gene in Türkiye. We anticipate that this data can be used in future CAdV-2 vaccine development studies. Further studies are recommended to evaluate the impact of these mutations on viral tropism and other host interactions.

First molecular detection of adenoviruses in bats from an urban Atlantic Forest in Rio de Janeiro, Brazil

Bats comprise one of the most diverse and abundant groups of mammals in the world and host a significant viral diversity with zoonotic potential. Bat adenoviruses (bat AdVs), members of the family Adenoviridae, have been detected in several bat species, suggesting that bats are natural reservoirs. Here, faeces and rectal/anal-swabs were collected from 321 bats of an urban Atlantic Forest remnant from Rio de Janeiro, during 2019-2022, and screened for bat AdV nucleic acid with PCR. The positivity of bat AdVs was 3.7 % (12/321). Twelve individuals of four bat species were infected: Artibeus lituratus (66.7 %; 8/12), Desmodus rotundus (8.3 %; 1/12), Platyrrhinus lineatus (16.7 %; 2/12), and Sturnira lilium (8.3 %; 1/12). Phylogenetic analysis based on nucleotide and amino acid sequences showed that the detected bat AdVs clustered into four clades corresponding to the host species, identifying the presence of two potentially new bat adenoviruses. This is the first report of bat AdV detected in Platyrrhinus lineatus.

Small RNA sequencing analysis reveals regulation of microRNA expression in Madin-Darby canine kidney epithelial cells infected with Canid alphaherpesvirus 1

Canid alphaherpesvirus 1 (CHV-1) infection can cause spontaneous abortions in pregnant dams, and in young puppies, fatal systemic infections are common. MicroRNAs (miRNAs) affect viral infection by binding to messenger RNAs, and inhibiting expression of host and/or viral genes. We conducted deep sequencing of small RNAs in CHV-1-infected and mock-infected Madin-Darby Canine Kidney (MDCK) epithelial cells, and detected sequences corresponding to 282 cellular miRNAs. Of these, 18 were significantly upregulated at 12 h post-infection, most of which were encoded on the X chromosome. We next quantified the mature forms of several of the miRNAs using stem loop RT-qPCR. Our results revealed a discordance between the levels of small RNAs corresponding to canine miRNAs, and levels of the corresponding mature miRNAs, which suggests a block in miRNA biogenesis in infected cells. Nevertheless, we identified several mature miRNAs that exhibited a statistically significant increase upon infection. These included cfa-miR-8908b, a miRNA of unknown function, and cfa-miR-146a, homologs of which target innate immune pathways and are known to play a role in other viral infections. Interestingly, ontology analysis predicted that cfa-miR-8908b targets factors involved in the ubiquitin-like protein conjugation pathway and peroxisome biogenesis among other cellular functions. This is the first study to evaluate changes in miRNA levels upon CHV-1 infection. Based on our findings, we developed a model whereby CHV-1 infection results in changes in levels of a limited number of cellular miRNAs that target elements of the host immune response, which may provide clues regarding novel therapeutic targets.

Molecular Detection of Viral and Bacterial Pathogens in Red Foxes (Vulpes vulpes) from Italy

Animals, including wildlife, are part of One-Health concept since many infectious diseases can affect both humans and animals. In this study, 126 red foxes (Vulpes vulpes) from Northern Italy in 2022-2023 were tested by molecular assays for Protoparvovirus carnivoran 1 (PPVC-1), Canine adenovirus type 1 and 2 (CAdV-1 and CAdV-2), Circovirus canine (CanineCV), Canine distemper virus (CDV), and Leptospira spp. A total of 39 of 126 (30.9%) red foxes were infected with at least one pathogen and five of these were coinfected: 20/126 (15.9%) red foxes tested positive for PPVC-1, 3/126 (2.4%) for CAdV, 20/126 (15.9%) for CanineCV, and 2/126 (1.6%) for Leptospira spp. DNA. No foxes tested positive for CDV RNA. The pathogens identified were genetically analysed. New findings were reported such as a fox with multiple feline panleukopenia virus (FPV) and canine parvovirus type 2b (CPV-2b) infection associated with quasispecies dynamics, typical genetic characteristics of the identified CanineCV, and the first detection in red foxes of Leptospira ST198 related to L. interrogans serogroup Australis. Further studies are necessary to investigate the transmission between domestic animals and wildlife and to understand the role of red foxes in the maintenance of these pathogens not only in the wild but also in urban and peri-urban environments.

Adenoviral Vector System: A Comprehensive Overview of Constructions, Therapeutic Applications and Host Responses

Adenoviral vectors are crucial for gene therapy and vaccine development, offering a platform for gene delivery into host cells. Since the discovery of adenoviruses, first-generation vectors with limited capacity have evolved to third-generation vectors flacking viral coding sequences, balancing safety and gene-carrying capacity. The applications of adenoviral vectors for gene therapy and anti-viral treatments have expanded through the use of in vitro ligation and homologous recombination, along with gene editing advancements such as CRISPR-Cas9. Current research aims to maintain the efficacy and safety of adenoviral vectors by addressing challenges such as pre-existing immunity against adenoviral vectors and developing new adenoviral vectors from rare adenovirus types and non-human species. In summary, adenoviral vectors have great potential in gene therapy and vaccine development. Through continuous research and technological advancements, these vectors are expected to lead to the development of safer and more effective treatments.

Immunogenicity of a novel inactivated canine adenovirus type 2 variant vaccine for dogs

Purpose

The immunogenicity of vaccines containing the canine adenovirus (CAdV) type 2 (CAdV-2) variant has not yet been reported. We prepared a novel inactivated CAdV-2 variant vaccine using the CAV2232-41 strain, and evaluated its safety and immunogenicity in raccoon dogs.

Materials and Methods

The growth kinetics of CAV2232-41 were determined using Madin-Darby Canine Kidney (MDCK) cells. The nucleotide sequences of CAV2232 and CAV2232-41 were determined by next-generation sequencing. To generate the CAdV-2 variant vaccine, CAV2232-41 propagated in the MDCK cells was inactivated with 0.1% formaldehyde. Two vaccines were prepared by blending inactivated CAV2232-41 with Cabopol and Rehydragel adjuvants. Safety and immunogenicity of the CAV2232C and CAV2232R vaccines were evaluated in guinea pigs. Safety and immunogenicity of the CAV2232C vaccine were also evaluated in raccoon dogs. The virus neutralizing antibody (VNA) titer against CAV2232-41 was measured in sera collected from immunized guinea pigs and raccoon dogs.

Results

CAV2232-41 showed the highest viral titer on days 4-6 post-inoculation and had a deletion in the E3 gene, which was confirmed as a CAdV-2 variant. Guinea pigs inoculated with CAV2232C showed slightly higher VNA titers than those inoculated with CAV2232R 2 weeks after booster vaccination. Raccoon dogs immunized with the CAV2232C vaccine developed high mean VNA titers, while non-vaccinated raccoon dogs were antibody-negative.

Conclusion

The CAV2232C vaccine is safe and induces a protective VNA titer in raccoon dogs.

Novel Alpha-, Beta-, and Gammaherpesviruses in Neotropical Carnivores of Brazil

The knowledge regarding infectious agents affecting wildlife is crucial for species' conservation. We hypothesized that herpesviruses are present in wild Neotropical carnivores. Herein, we used DNA polymerase and glycoprotein B broad-spectrum PCRs to molecularly survey the presence of herpesviruses in spleen and/or lung samples of 53 wild Neotropical carnivores of Brazil, comprising the families Canidae, Felidae, Mustelidae, and Procyonidae. The percentage of PCR-positives was 28.3% (15/53). An alphaherpesvirus was found in a Neotropical river otter (Lontra longicaudis, 1/1), a betaherpesvirus in a lesser grison (Galictis cuja, 1/3), and different gammaherpesviruses in Neotropical river otter (1/1), lesser grison (1/3), crab-eating raccoons (Procyon cancrivorus, 8/9), South American coati (Nasua nasua, 1/2), southern tiger cat (Leopardus guttulus, 1/2), jaguarundi (Puma yagouaroundi, 1/5), and ocelot (Leopardus pardalis, 1/10). None of the tested canids were herpesvirus-positive. This is the first report of herpesvirus in procyonids, and in jaguarundi, southern tiger cat, lesser grison, and Neotropical river otter. This study broadens the host range of herpesviruses in Neotropical carnivores.

Prevalence of Chlamydophila spp. and Canid herpesvirus-1 in Polish dogs

Background and Aim

Chlamydophila spp. affect Leydig and Sertoli cells by dysregulating spermatogenesis, inducing apoptosis and sperm DNA fragmentation, as well as benign prostate hyperplasia. Canid herpes virus 1 (CHV-1) infection in male dogs is manifested by lesions on the base of the penis and foreskin. There is a lack of information on the influence of these microorganisms on the quality of canine semen. Seroprevalence of Chlamydophila spp. (55%-61%) and CHV-1 (22%-81%) in Europe is high. The prevalence of Chlamydophila spp. and CHV-1 has been evaluated using polymerase chain reaction (PCR) only in Sweden and Croatia, respectively. No positive samples were detected in either case. The aim of this study was to evaluate the epidemiological situation in Polish male dogs (PMDs) to provide a solution to limit the spread of these microorganisms using assisted reproduction techniques or elimination from the reproduction of CHV-1 carriers. In addition, we assessed the semen quality of Chlamydophila spp. carriers and CHV-1 carriers.

Materials and Methods

Cotton swabs were collected from prepuce or semen from each dog (n = 130). Real-time PCR for Chlamydophila spp. and CHV-1, as well as semen analysis, was performed using the computer-assisted semen analysis system.

Results

To the best of our knowledge, this is the first report of Chlamydophila spp. infection in PMD confirmed by real-time PCR. All parameters, except progressive movement in Chlamydophila semen carriers, were normal.

Conclusion

The average velocity values for a dog with Chlamydia are detailed. No CHV-1 was detected. The results achieved should be verified on the basis of a larger number of studies. However, the high prevalence of these pathogens in the PMD population has not been established.

Turkey adenovirus 3: ORF1 gene sequence comparison between vaccine-like and field strains

Haemorrhagic enteritis is an economically significant disease reported in the majority of the countries where turkeys are raised intensively; it is caused by Turkey adenovirus 3 (TAdV-3). The aim of this study was to analyse and compare the ORF1 gene 3' region from turkey haemorrhagic enteritis virus (THEV) vaccine-like and field strains in order to develop a molecular diagnostic method to differentiate the strains from each other. Eighty samples were analysed by sequencing and phylogenetic analyses using a new set of polymerase chain reaction (PCR) primers targeting a genomic region spanning the partial ORF1, hyd and partial IVa2 gene sequences. A commercial live vaccine was also included in the analysis. The results showed that 56 of the 80 sequences obtained in this study showed ≥99.8% nucleotide identity with the homologous vaccine strain sequence. Three non-synonymous mutations - ntA1274G (aaI425V), ntA1420C (aaQ473H) and ntG1485A (aaR495Q) - were detected in the THEV field strains but not in the vaccine strain. Phylogenetic analysis confirmed the clustering of the field and vaccine-like strains in different phylogenetic branches. In conclusion, the method employed in this study could be a useful tool towards making a correct diagnosis. The data could contribute to the knowledge of field distribution of THEV strains and increase the limited existing information available on native isolates around the world.

Causes of pregnancy arrest in the canine species

In the canine species, early pregnancy arrest before 30-40 days of pregnancy will induce intra-uterine embryonic or foetal resorption, with very few clinical signs. If no genital examination by ultrasound is performed at that time, it will often remain unnoticed and the bitch will be qualified as infertile. It is only when pregnancy stops at a later stage, mostly after 40 days, that clinical signs will be seen. Expulsion of aborted foetuses or placentas may be observed, although the dam frequently eats the expelled tissues. Intra-uterine mummification may also occur. This article reviews the causes of pregnancy termination in the bitch, both at the embryonic and the foetal stages, reported in the literature. Canine brucellosis is by far the most important disease concerned in this aspect. There is an important current concern about this disease, due to the fact that several outbreaks have been observed recently in Europe, and that it is a very contagious disease; it may be an underestimated zoonosis. Other bacterial causes of pregnancy arrest are sporadic. There is, however, a growing attention towards the microbiological content of raw food diets which are more and more popular among dog breeders and may-if badly prepared-contain abortifacient bacteria such as Campylobacter jejuni or Listeria monocytogenes. The abortifacient role of endogenous vaginal bacteria and mycoplasms remains unclear and may be related to an imbalanced vaginal flora with subsequent ascending bacterial contamination of the uterus. The role of Canine Herpesvirus on abortion is controversial and probably not frequent. Other viruses have been shown experimentally to induce abortion but their natural occurrence in this respect remains unknown. The same applies to the parasite Neospora caninum which is suspected, but not proven, potentially to induce pregnancy arrest in bitches. Among non-infectious causes, uterine pathology such as cystic endometrial hyperplasia (CEH) or sub-clinical post-mating endometritis which can cause infertility and may also induce embryonic resorption. The role of luteal insufficiency in pregnancy arrest is probably overestimated.

Pathology of Perinatal Disorders

Perinatal deaths including abortions, stillbirths, and neonatal deaths are an important economic and emotional challenge for companion animal owners, breeders, and veterinarians. A protocol for the investigation of perinatal deaths in dogs and cats is described, including examination of the placenta. Specific lesions of common infectious diseases leading to perinatal death are presented, as well as the more prevalent noninfectious causes. These include viruses, bacteria, protozoa, metabolic causes, "accidents of pregnancy," nutritional deficiencies, intoxications, hormonal causes, and heritable and nonheritable congenital defects.

Detection of Selected Canine Viruses in Nigerian Free-Ranging Dogs Traded for Meat Consumption

Animal trade favors the spreading of emerging and re-emerging pathogens. Concerns have been previously expressed regarding the risks of dog trade in spreading zoonotic pathogens in Nigeria. However, the role of these dogs in disseminating highly pathogenic canine viruses has not yet been explored. The present study aimed to identify selected canine viruses in dogs traded for meat consumption in Nigeria. A total of 100 blood samples were screened for carnivore protoparvovirus-1 (CPPV-1), canine adenovirus 1/2 (CAdV-1/2), canine circovirus (CaCV), and canine distemper virus (CDV) by using real-time PCR and conventional PCR and/or sequencing. CPPV-1 DNA was identified in 83% of canine samples while CaCV DNA and CDV RNA were detected in 14% and 17% of the dog samples, respectively. None of the dogs tested positive for CAdV-1/2. The CaCVs identified in this study clustered along with other European, Asian, and American strains. Moreover, CDV strains identified in Nigeria clustered in a separate lineage with the closest genetic relatedness to the Europe-South America-1 clade. Further surveys prior to and after arrival of dogs at the slaughtering points are required to clarify the real virus burden in these animals.

Canine distemper virus and canine adenovirus type 1 co-infection in a free-living hoary fox (Lycalopex vetulus) from Brazil

The present case is the first description of a co-infection with canine distemper virus (CDV) and canine adenovirus type 1 (CAdV-1) in a free-living hoary fox pup from Brazil. The animal was found and rescued with poor body condition, dehydration, incoordination, ataxia, excessive vocalization, and "blue eyes" phenomenon. Despite the efforts, euthanasia was elected due to worsening clinical signs and poor prognosis. Pathologic examination revealed a mild, acute, random, necrotizing hepatitis, acute bronchopneumonia, hydrocephalus, corneal edema with epithelium degeneration, and acidophilic intracytoplasmatic inclusion bodies in different epithelial cells types with rare syncytial. Through immunohistochemistry, CDV antigen was observed in the tongue, trachea, lungs, liver, spleen, stomach, intestine and urinary bladder. Adenovirus antigen was identified in the nucleus of scattered hepatocytes. Polymerase chain reaction and sequencing demonstrated high similarity with CAdV-1 and wild-type strain of CDV close related to Brazilian viral lineages isolated from domestic dogs. Disease surveillance in wildlife animals is essential to assess possible conservation threats and consider the implementation of mitigation or control measures.

Investigation of canine chaphamaparvovirus, canine bufavirus, and canine adenovirus in dogs with diarrhea: First report of novel canine bufavirus in Turkey

Viral enteritis is a significant cause of death among dogs younger than 6 months. In this study, the presence of canine chaphamaparvovirus (CaChPV), canine bufavirus (CBuV), and canine adenovirus (CAdV) was investigated in 62 diarrheal dogs previously tested for other viral pathogens (canine parvovirus type 2, canine coronavirus, and canine circovirus). CBuV was detected in two dogs (3.22%) and CaChPV in one dog (1.61%). One dog tested positive for three parvoviruses (CPV-2b, CBuV, and CaChPV). All dogs tested negative to CAdV-1/CAdV-2. A long genome fragment of one of the two identified CBuVs and of the CaChPV was obtained and analyzed. New Turkish CBuVs had high identity rates (96%-98% nt; 97%-98% aa) with some Italian CBuV strains (CaBuV/9AS/2005/ITA and CaBuV/35/2016/ITA). The phylogenetic analysis powerfully demonstrated that these viruses belonged to a novel genotype (genotype 2). A part of the genome ChPV-TR-2021-19 revealed high identity rates (> 98% nt and > 99% aa) with some Canadian CaChPV strains (NWT-W88 and NWT-W171) and the Italian CaChPV strain Te/37OVUD/2019/IT. This study is the first report on the detection of CBuV-2 and the concomitant presence of three canine parvoviruses in Turkey. The obtained data will contribute to the molecular epidemiology and the role in the etiology of enteric disease of new parvoviruses.

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Dogs

Canine vaccination is the main tool for preventing dangerous and widespread diseases. The strongly recommended (core) dog vaccines are against Canine Parvovirus type 2 (CPV-2), Canine Distemper Virus (CDV), and Canine Adenovirus (CAdV-1), but vaccination protocols should be tailored to dog lifestyles. Vaccination guidelines suggest vaccinating adult dogs no more frequently than every 3 years using modified live (attenuated) vaccines (MLV), thus obtaining a long-lasting (sometimes throughout life) specific protection in many but not all animals. The aim of this study was to determine the actual levels of seroprotection against CPV-2, CDV and CAdV-1 in a cohort of Italian dogs by using the in-practice test VacciCheck. A total of 1,027 dogs (951 vaccinated and 76 unvaccinated) were analyzed for Protective Antibody Titers (PATs) against CPV-2, CDV, and CAdV-1. Differences related to sex, age, breed size, health status, and time elapsed since last vaccination were evaluated. Half of the entire canine cohort (50.6%) had PATs for all three viruses (68.5% considering only vaccinated dogs). In particular, 90.8% of dogs were protected against CPV-2, 68.6% against CDV, and 79.8% against CAdV-1. Most dogs remained protected for 3 years after vaccination or longer. Revaccination on a 3-year basis can then be recommended for core MLV vaccines without altering individual's seroprotection or even herd immunity.

Study on the Canine Adenovirus Type 1 (CAdV-1) Infection in Domestic Dogs in Southern Italy

Canine adenovirus type 1 (CAdV-1) is the causative agent of a systemic and potentially fatal viral disease of domestic and wild canids. In Italy, CAdV-1 infection has also been occasionally described in dogs, but information on the epidemiology and its genomic features is still limited. A study was conducted on 291 dogs suspected of infectious gastrointestinal disease. Samples collected from dogs in southern Italy between 2017 and 2020 were analyzed. Virological and histopathological assays were carried out. The presence of CAdVs and other canine viral enteropathogens was investigated, and sequence and phylogenetic analyses were performed. CAdV-1 was detected in six (2.1%) dead stray dogs alone or in mixed infections with other viruses. Gross lesions and histopathological findings referred to CAdV infection were observed, also involving the central nervous system tissues. All inoculated samples were successfully isolated. Sequence analysis evidenced divergences with the circulating strains previously described in Italy and a closer relation with older CAdV-1 strains collected from other countries, suggesting a genetic heterogeneity of CAdV-1 in Italy. The evidence of the circulation of CAdV-1 and its genomic features allows us to have more in-depth knowledge of the epidemiology and evolution of the CAdV-1 genomic variants.

Successful treatment of coagulation disorders and hypoalbuminaemia in a puppy with Infectious Canine Hepatitis

Due to high vaccination coverage of the dog population in Western and Middle Europe, veterinarians are usually not familiar with clinical signs and treatment of Infectious Canine Hepatitis (ICH). This case report describes a 4-month-old female mixed breed dog that was imported from Bulgaria. According to the history, the puppy was presented with lethargy, pyrexia, icterus and melaena. On clinical examination, the dog additionally exhibited a painful abdomen and bleeding tendency at the venous puncture sites. Blood analysis revealed anaemia, left shift without leucocytosis, increased liver enzymes and prolonged coagulation times. Polymerase Chain Reaction (PCR) and subsequently sequence analysis performed out of urine confirmed Canine Adenovirus 1 (CAV-1) as the causative agent of the disease. Peripheral oedema developed on the dog´s head and limbs during the progression of the disease due to severe hypoalbuminaemia. Initial treatment of the puppy included transfusion of whole blood and fresh frozen plasma. Hypoalbuminaemia was treated by transfusion using human albumin. On day eight after starting the treatment, the dog was released from the hospital due to an unremarkable clinically condition. This case report indicates that ICH might become a re-emerging disease by means of rising dog imports. Especially, the severe form of ICH can be associated with several life-threatening complications that require hospitalisation and intensive care treatment.

Development of a three-panel multiplex real-time PCR assay for simultaneous detection of nine canine respiratory pathogens

Infectious respiratory disease is one of the most common diseases in dogs worldwide. Several bacterial and viral pathogens can serve as causative agents of canine infectious respiratory disease (CIRD), including Mycoplasma cynos, Mycoplasma canis, Bordetella bronchiseptica, canine adenovirus type 2 (CAdV-2), canine herpesvirus 1 (CHV-1), canine parainfluenza virus (CPIV), canine distemper virus (CDV), canine influenza virus (CIA) and canine respiratory coronavirus (CRCoV). Since these organisms cause similar clinical symptoms, disease diagnosis based on symptoms alone can be difficult. Therefore, a quick and accurate test is necessary to rapidly identify the presence and relative concentrations of causative CIRD agents. In this study, a multiplex real-time PCR panel assay was developed and composed of three subpanels for detection of the aforementioned pathogens. Correlation coefficients (R²) were >0.993 for all singleplex and multiplex real-time PCR assays with the exception of one that was 0.988; PCR amplification efficiencies (E) were between 92.1% and 107.8% for plasmid DNA, and 90.6-103.9% for RNA templates. In comparing singular and multiplex PCR assays, the three multiplex reactions generated similar R² and E values to those by corresponding singular reactions, suggesting that multiplexing did not interfere with the detection sensitivities. The limit of detection (LOD) of the multiplex real-time PCR for DNA templates was 5, 2, 3, 1, 1, 1, 4, 24 and 10 copies per microliter for M. cynos, M. canis, B. brochiseptica, CAdV-2, CHV-1, CPIV, CDV, CIA and CRCoV, respectively; and 3, 2, 6, 17, 4 and 8 copies per microliter for CAdV-2, CHV-1, CPIV, CDV, CIA and CRCoV, respectively, when RNA templates were used for the four RNA viruses. No cross-detection was observed among the nine pathogens. For the 740 clinical samples tested, the newly designed PCR assay showed higher diagnostic sensitivity compared to an older panel assay; pathogen identities from selected samples positive by the new assay but undetected by the older assay were confirmed by Sanger sequencing. Our data showed that the new assay has higher diagnostic sensitivity while maintaining the assay's specificity, as compared to the older version of the panel assay.

Adenovirus surveillance in wild carnivores from Brazil

Landscape transformation favors the spread of new pathogens that can be shared between domestic and wild animals. Certain adenoviruses (e.g., canine adenovirus 1 and 2, family Adenoviridae) can infect domestic and wild carnivores. In domestic canids, these viruses are associated with hepatic and respiratory diseases (among others). Nevertheless, information regarding adenovirus pathogenicity and molecular features in wild carnivores is still limited. Herein we surveyed adenovirus in free-ranging carnivores from Brazil. Total DNA was extracted from and subsequently tested by a nested panPCR in spleen and/or lung of 52 carnivores, representing species of the following families: Canidae (n = 4), Felidae (n = 3), Mustelidae (n = 2) and Procyonidae (n = 2). The obtained sequences were compared to others available at GenBank. Available tissue samples from the positive cases were evaluated histopathologically. One out of 52 (1.9%, CI 95%, 0.0-5.7%) carnivores was positive; a roadkilled ocelot (Leopardus pardalis). The obtained sequence presented a low deduced amino acid (78.1%) similarity with the closest adenovirus, identified in a pinniped from the United States of America. This fact and its detection in a novel host suggest it may be representative of a novel species and denominated ocelot adenovirus 1. None of the gross and microscopic findings of the positive case were associated with adenovirus. To the authors' knowledge, this is the first report of adenovirus in wild felids of South America and the second worldwide. Further studies are necessary to assess the epidemiology and potential pathogenicity of this agent in wild carnivores.

Detection and Genetic Characterization of Canine Adenoviruses, Circoviruses, and Novel Cycloviruses From Wild Carnivores in Italy

Wild carnivores are known to play a role in the epidemiology of several canine viruses, including canine adenoviruses types 1 (CAdV-1) and 2 (CAdV-2), canine circovirus (CanineCV) and canine distemper virus (CDV). In the present study, we report an epidemiological survey for these viruses in free ranging carnivores from Italy. A total of 262 wild carnivores, including red foxes (Vulpes vulpes), wolves (Canis lupus) and Eurasian badgers (Meles meles) were sampled. Viral nucleic acid was extracted and screened by real-time PCR assays (qPCR) for the presence of CAdVs and CanineCV DNA, as well as for CDV RNA. CAdV-1 DNA was detected only in red foxes (4/232, 1.7%) whilst the wolves (0/8, 0%) and Eurasian badgers (0/22, 0%) tested negative. CanineCV DNA was detected in 4 (18%) Eurasian badgers, 4 (50%) wolves and 0 (0%) red foxes. None of the animals tested positive for CDV or CAdV-2. By sequence and phylogenetic analyses, CAdV-1 and CanineCV sequences from wild carnivores were closely related to reference sequences from domestic dogs and wild carnivores. Surprisingly, two sequences from wolf intestines were identified as cycloviruses with one sequence (145.20-5432) displaying 68.6% nucleotide identity to a cyclovirus detected in a domestic cat, while the other (145.201329) was more closely related (79.4% nucleotide identity) to a cyclovirus sequence from bats. A continuous surveillance in wild carnivores should be carried out in order to monitor the circulation in wildlife of viruses pathogenic for domestic carnivores and endangered wild species.

Difference Analysis Between Canine Adenovirus Types 1 And 2

Canine adenoviruses (CAdVs) include type 1 (CAdV-1, virulent strain) and type 2 (CAdV-2, attenuated strain). In recent years, the incidences of CAdV infections are increasing. However, they are difficult to distinguish when the symptoms are untypical. It is pivotal to find the differences between the two virus types for scientific, epidemiological, and specific treatment. CAdV-1 (virulent strain) and CAdV-2 (attenuated strain) induced canine hepatitis (ICH) and tracheobronchitis (ITB), respectively, but the clinical symptom is not obvious. CAdV-1 and CAdV-2 have the same genome structure, diameter, morphological features, and cytopathic features, but the same character hinder the diagnose time of the serotypes. CAdV-1 and CAdV-2 have a difference in the genome sequence, coding proteins, viral activity, hemagglutination patterns. After infection, pathogenicity and transmission route are different between the two serotypes. Sequence alignment, PCR, Real time-PCR assay are useful methods to distinguish the two serotypes. The attenuated live CAdV-2 vaccine is currently used to protect against CAdV-1, but it also has a risk. The further research should focus on the pathogenicity mechanism and the useful vaccine for the two serotypes of canine adenovirus.

A novel hepadnavirus in domestic dogs

Hepadnaviruses have been identified in several animal species. The hepadnavirus prototype, human hepatitis B virus (HBV), is a major public health problem associated with chronic liver diseases and hepatocellular carcinoma. Recently, a novel hepadnavirus, similar to HBV, was identified in domestic cats. Since several pathogens can be shared between cats and dogs, we hypothesized that dogs could also harbor hepadnaviruses and we tested a collection of canine sera with multiple molecular strategies. Overall, hepadnavirus DNA was identified in 6.3% (40/635) of canine serum samples, although the viral load in positive sera was low (geometric mean of 2.70 × 10² genome copies per mL, range min 1.36 × 10²—max 4.03 × 10⁴ genome copies per mL). On genome sequencing, the canine hepadnaviruses revealed high nucleotide identity (about 98%) and similar organization to the domestic cat hepadnavirus. Altered hepatic markers were found in hepadnavirus-positive dogs, although the role of hepadnavirus in canine health remains to be elucidated.

Development of a Recombinase Polymerase Amplification Fluorescence Assay for the Detection of Canine Adenovirus 2

Canine adenovirus type 2 (CAdV-2) is often found in co-infections with other pathogens causing canine infectious respiratory disease (CIRD). Rapid, efficient, and convenient pathogen detection is the best approach for early confirmatory diagnosis. In this study, we developed and evaluated a rapid real-time recombinase polymerase amplification (RPA) assay for detection of canine adenovirus 2 (CAV), which can detect CAV within 15 min at 39°C. The detection limit that assay was 214 copies/μl DNA molecules per reaction. The specificity was indicated by a lack of cross-reaction with canine distemper virus (CDV), canine coronavirus (CCV), and canine parvovirus (CPV). Field and clinical applicability of this assay were evaluated using 86 field samples. The coincidence rate of the detection results for clinical samples between CAV-RPA and qPCR was 97.7%. In summary, the real-time CAV-RPA analysis provides an efficient, rapid and sensitive detection method for CAV.

Entry of the Varicellovirus Canid herpesvirus 1 into Madin-Darby canine kidney epithelial cells is pH-independent and occurs via a macropinocytosis-like mechanism but without increase in fluid uptake

Canid herpesvirus 1 (CHV-1) is a Varicellovirus that causes self-limiting infections in adult dogs but morbidity and mortality in puppies. Using a multipronged approach, we discovered the CHV-1 entry pathway into Madin-Darby canine kidney (MDCK) epithelial cells. We found that CHV-1 triggered extensive host cell membrane lamellipodial ruffling and rapid internalisation of virions in large, uncoated vacuoles, suggestive of macropinocytosis. Treatment with inhibitors targeting key macropinocytosis factors, including inhibitors of Na⁺ /H⁺ exchangers, F-actin, myosin light-chain kinase, protein kinase C, p21-activated kinase, phosphatidylinositol-3-kinase and focal adhesion kinase, significantly reduced viral replication. Moreover, the effect was restricted to exposure to the inhibitors early in infection, confirming a role for the macropinocytic machinery during entry. The profile of inhibitors also suggested a role for signalling via integrins and receptor tyrosine kinases in viral entry. In contrast, inhibitors of clathrin, caveolin, microtubules and endosomal acidification did not affect CHV-1 entry into MDCK cells. We found that the virus colocalised with the fluid-phase uptake marker dextran; however, surprisingly, CHV-1 infection did not enhance the uptake of dextran. Thus, our results indicate that CHV-1 uses a macropinocytosis-like, pH-independent entry pathway into MDCK cells, which nevertheless is not based on stimulation of fluid uptake. TAKE AWAYS: CHV-1 enters epithelial cells via a macropinocytosis-like mechanism. CHV-1 induces extensive lamellipodial ruffling. CHV-1 entry into MDCK cells is pH-independent.

Canine circovirus and Canine adenovirus type 1 and 2 in dogs with parvoviral enteritis

Canine parvovirus type 2 (CPV-2) is one of the most relevant pathogens associated with enteritis in dogs and is frequently reported in association with the detection of other pathogens in faeces. In this study the concomitant presence of Canine circovirus (CanineCV) and Canine adenovirus (CAdV) DNA in faecal or intestine samples of 95 dogs with parvovirus enteritis sampled in Italy (1995–2017) was investigated and the viruses identified were genetically characterised. Potential correlations with the antigenic variant of CPV-2 and with signalment data and outcome were evaluated. Twenty-eight of 95 (29.5%) CPV-2 infected dogs tested positive to other viruses: 7/28 were also positive to CanineCV, 1/28 to CAdV-1, 18/28 to CAdV-2, 1/28 to CanineCV and CAdV-2, and 1/28 to CAdV-1 and CAdV-2. The frequency of CAdV DNA detection and coinfections was significantly higher in purebred dogs compared to mixed breed ones (P = 0.002 and 0.009, respectively). The presence of coinfection was not associated with any other relevant data available, including CPV-2 variant and final outcome. The detection of CanineCV in a dog sampled in 2009 allowed to backdating its circulation in dogs. The eight CanineCV completely sequenced were phylogenetically related to the CanineCV identified in dogs, wolves and a badger from Europe, USA, Argentina and China. Nine CAdV were partially sequenced and phylogenetic analysis showed a separate branch for the oldest CAdV-2 identified (1995). From the results obtained in this study population, CanineCV and CAdV coinfections in dogs with parvoviral enteritis did not result in more severe disease.

In vitro effects of bufotenine against RNA and DNA viruses

Bufotenine, an alkaloid that can be found in plant extracts and skin secretions of amphibians, is reported to have potential antiviral activity. The present study evaluated the antiviral activity of bufotenine against different genetic lineages of rabies virus (RABV, a single-stranded, negative-sense RNA virus), canine coronavirus (CCoV, a positive-sense RNA virus) and two double-stranded DNA viruses (two strains of herpes simplex virus type 1/HSV-1 [KOS and the acyclovir-resistant HSV-1 strain 29R] and canine adenovirus 2, CAV-2). The maximal non-toxic bufotenine concentrations in Vero and BHK-21 cells were determined by MTT assays. The antiviral activity of bufotenine against each virus was assessed by examination of reductions in infectious virus titres and plaque assays. All experiments were performed with and without bufotenine, and the results were compared. Bufotenine demonstrated significant RABV inhibitory activity. No antiviral action was observed against CCoV, CAV-2 or HSV-1. These findings indicate that the antiviral activity of bufotenine is somewhat linked to the particular infectious dose used and the genetic lineage of the virus, although the mechanisms of its effects remain undetermined.

Integrated Use of Molecular Techniques to Detect and Genetically Characterise DNA Viruses in Italian Wolves (Canis lupus italicus)

Simple Summary

In our study, different quantitative and qualitative molecular techniques were used to detect and genetically characterise Carnivore protoparvovirus 1, Canine adenovirus type 1 and 2 (CAdV-1 and CAdV-2), and Canine circovirus (CanineCV) in Italian wolves (Canis lupus italicus) of the Italian Apennines. Carnivore protoparvoviruses were the most frequently detected viruses, followed by CanineCV and CAdV. All the wolves tested positive for at least one of the DNA viruses screened, and 47.8% of the subjects were coinfected with two or three viruses. From viral sequences analysis, close correlations emerged between the viruses identified in the wolves and those circulating in domestic dogs, suggesting that the same viruses infect wolves and domestic dogs. Further studies are needed to investigate if pathogens are transmitted between the two species.

Abstract

In this study, internal organs (tongue, intestine, and spleen) of 23 free-ranging Italian wolves (Canis lupus italicus) found dead between 2017 and 2019 were tested for Carnivore protoparvovirus 1, Canine adenovirus (CAdV), and Canine circovirus (CanineCV) using real-time PCR assays. Genetic characterisation of the identified viruses was carried out by amplification, sequencing, and analysis of the complete viral genome or informative viral genes. All the wolves tested positive for at least one of the DNA viruses screened, and 11/23 were coinfected. Carnivore protoparvoviruses were the most frequently detected viruses (21/23), followed by CanineCV (11/23) and CAdV (4/23). From the analysis of the partial VP2 gene of 13 carnivore protoparvoviruses, 12 were canine parvovirus type 2b, closely related to the strains detected in dogs and wild carnivores from Italy, and one was a feline panleukopenia-like virus. Of the four CAdV identified, two were CAdV-1 and two were CAdV-2. The complete genome of seven CanineCVs was sequenced and related to the CanineCV identified in dogs, wolves, and foxes worldwide. Close correlations emerged between the viruses identified in wolves and those circulating in domestic dogs. Further studies are needed to investigate if these pathogens may be potentially cross-transmitted between the two species.

The Gut Viral Metagenome Analysis of Domestic Dogs Captures Snapshot of Viral Diversity and Potential Risk of Coronavirus

The close relations between dogs (Canis lupus familiaris) and humans lay a foundation for cross species transmissions of viruses. The co-existence of multiplex viruses in the host accelerate viral variations. For effective prediction and prevention of potential epidemic or even pandemic, the metagenomics method was used to investigate the gut virome status of 45 domestic healthy dogs which have extensive contact with human beings. A total of 248.6 GB data (505, 203, 006 valid reads, 150 bp in length) were generated and 325, 339 contigs, which were best matched with viral genes, were assembled from 46, 832, 838 reads. In the aggregate, 9,834 contigs (3.02%) were confirmed for viruses. The top 30 contigs with the most reads abundance were mapped to DNA virus families Circoviridae, Parvoviridae and Herpesviridae; and RNA virus families Astroviridae, Coronaviridae and Picornaviridae, respectively. Numerous sequences were assigned to animal virus families of Astroviridae, Coronaviridae, Circoviridae, etc.; and phage families of Microviridae, Siphoviridae, Ackermannviridae, Podoviridae, Myoviridae and the unclassified phages. Further, several sequences were homologous with the insect and plant viruses, which reflects the diet and habitation of dogs. Significantly, canine coronavirus was uniquely identified in all the samples with high abundance, and the phylogenetic analysis therefore showed close relationship with the human coronavirus strain 229E and NL63, indicating the potential risk of canine coronavirus to infect humans by obtaining the ability of cross-species transmission. This study emphasizes the high detection frequency of virus harbored in the enteric tract of healthy contacted animal, and expands the knowledge of the viral diversity and the spectrum for further disease-association studies, which is meaningful for elucidating the epidemiological and biological role of companion animals in public health.

Intensive ocular sampling for the detection of subclinical canine herpesvirus-1 shedding in dogs with experimentally-induced latent infection

Latent canine herpesvirus-1 (CaHV-1) infections are common in domestic dogs, but viral shedding patterns in dogs are poorly understood. Previous research failed to detect spontaneous subclinical ocular CaHV-1 shedding in dogs following ocular infection, a situation that is fundamentally distinct from many of the alphaherpesviruses closely related to CaHV-1. One possible explanation for this finding is that the sampling interval in the prior studies evaluating ocular shedding patterns was too infrequent to detect rapidly cleared, brief ocular viral shedding episodes. To evaluate for this potential viral shedding scenario, 10 laboratory beagles recovered from experimental primary ocular CaHV-1 infection and with latent CaHV-1infection were intensively monitored for viral reactivation and shedding for 28 days. Clinical ophthalmic examinations were performed daily. Ocular swab samples were collected for CaHV-1 polymerase chain reaction 3 times daily and CaHV-1 virus neutralizing antibody assays were evaluated at 2-week intervals. No abnormalities suggestive of recurrent CaHV-1 ocular disease were observed during clinical ophthalmic examination in the dogs during the study. Ocular CaHV-1 shedding was not detected by polymerase chain reaction and CaHV-1 virus neutralizing antibody titers remained stable in all dogs for the study duration. In the present study utilizing frequent multiple daily sample collections, no evidence of subclinical ocular CaHV-1 shedding was detected in mature dogs with experimentally-induced latent CaHV-1 infection.

The biological characteristics of the canine adenovirus type 1 from fox and the transcriptome analysis of the infected MDCK cell

Canine adenovirus type 1 (CAdV-1) is the etiologic agent of fox encephalitis, and a virus strain from fox encephalitis is isolated and related research are conducted. In this experiment, the results showed that the F1301 strain was confirmed to be the CAdV-1. The whole genome of the CAdV-1 F1301 strain isolated from fox was 30,535 bp and had higher homology to the other reported CAdV-1 strains. After 0, 12, and 36 h of CAdV-1 infection, the difference gene of the 592 long noncoding RNA and 11,215 microRNA were involved in cell responses to CAdV-1 infection through the PI3K-AKT, Wnt, Herpes simplex, hepatitis C, and Epstein-Barr virus infection pathway in Madin-Darby canine kidney cell line (MDCK). The results indicate that the biological characterization of the CAdV-1 and the MDCK cell-CAdV-1 interaction are clarified.

Biodistribution Analysis of Oncolytic Adenoviruses in Canine Patient Necropsy Samples Treated with Cellular Virotherapy

Oncolytic immunotherapy with competent viruses is an emerging approach in cancer treatment. The clinical safety of many types of oncolytic viruses (OVs) has been demonstrated. However, there is a lack of information about viral biodistribution in patients. The available data about oncolytic adenovirus biodistribution in human subjects treated intravenously consists of virus detection in body fluids, a few tumor biopsies, and a single report of patient necropsy samples. There is no information about adenoviral biodistribution in patients treated intravenously with cellular vehicles carrying an oncolytic adenovirus. We previously published reports regarding the efficacy and clinical safety of infusing mesenchymal stem cells (MSCs) infected with an OV in human and canine patients. In this study, we performed necropsies on 12 canine patients treated with dCelyvir, canine MSCs infected with ICOCAV17, a canine oncolytic adenovirus. The prevalence of microscopic lesions, especially chronic inflammatory responses in different organs, was higher than expected. Concomitantly, we found a positive immunoreaction to ICOCAV17 in analyzed samples. These findings support a possible role of the virus in development of histopathological alterations and ongoing systemic viral replication of ICOCAV17 in the period after therapy administration.

Effects of Mustelid gammaherpesvirus 1 (MusGHV-1) Reactivation in European Badger (Meles meles) Genital Tracts on Reproductive Fitness

Reactivation of latent Gammaherpesvirus in the genital tract can lead to reproductive failure in domestic animals. Nevertheless, this pathophysiology has not received formal study in wild mammals. High prevalence of Mustelid gammaherpesvirus 1 (MusGHV-1) DNA detected in the genital tracts of European badgers (Meles meles) implies that this common pathogen may be a sexual transmitted infection. Here we used PCR to test MusGHV-1 DNA prevalence in genital swabs collected from 144 wild badgers in Ireland (71 males, 73 females) to investigate impacts on male fertility indicators (sperm abundance and testes weight) and female fecundity (current reproductive output). MusGHV-1 reactivation had a negative effect on female reproduction, but not on male fertility; however males had a higher risk of MusGHV-1 reactivation than females, especially during the late-winter mating season, and genital MusGHV-1 reactivation differed between age classes, where 3-5 year old adults had significantly lower reactivation rates than younger or older ones. Negative results in foetal tissues from MusGHV-1 positive mothers indicated that cross-placental transmission was unlikely. This study has broader implications for how wide-spread gammaherpesvirus infections could affect reproductive performance in wild Carnivora species.

Canine parvovirus vaccination and immunisation failures: Are we far from disease eradication?

Despite extensive vaccination, canine parvovirus (CPV) remains a leading infectious cause of canine mortality, especially among juveniles. This review provides an update on CPV vaccine types and vaccination protocols. The design of CPV prevention strategies and vaccination programs with a goal of herd immunity has been hampered by deficiencies of studies that model companion animal viral infections and inform an understanding of the basic reproduction number. However, the most important issue in eradication of CPV disease is represented by immunisation failures including: i) the presence of interfering titres of maternally-derived antibodies; ii) the presence of non-responders; and iii) possible reversion to virulence. In contrast, the role of the CPV variants in immunisation failures is widely debated. Taking into account the reduced circulation of canine distemper virus and canine adenovirus type 1 in countries where extensive vaccination is carried out, more effort should be made to aim for CPV eradication, including antibody testing to determine the optimal time for vaccinations of pups and adults and homogeneous vaccine coverage of dog population.

Comparison of immunity against canine distemper, adenovirus and parvovirus after vaccination with two multivalent canine vaccines

BACKGROUND

Viral diseases are a major cause of morbidity and mortality in puppies. There is a belief among veterinary practitioners and even educational institutions that the vaccines made in Brazil against canine distemper virus (CDV), canine parvovirus (CPV) and canine adenovirus (CAV) are ineffective or only partially effective.

OBJECTIVES

This study aimed at comparing the immunity of two multivalent vaccines in adult dogs in the city of Uberlândia, Minas Gerais state, Brazil.

METHODS

The study was carried out at the Animal Protection Association and a total of 60 adult mongrel dogs were selected and divided into two groups. Group A was immunized with two doses of Elevencell® vaccine and Group B received two doses of imported vaccine from the United States; each group was made up of 14 females and 14 males.

RESULTS

In group A, the Elevencell vaccine generated a protective antibody titre against CDV in 26 out of 28 subjects (92.85%), CPV in 24 out of 28 subjects (85.71%) and CAV in 26 out of 28 subjects (92.85%). In group B, the imported US vaccine generated a protective antibody titre against CDV in 22 out of 28 subjects (78.57), CPV in 21 out of 28 subjects (75%) and CAV in 25 out of 28 subjects (89.28%). There was no statistical difference between titres generated between vaccine types for any of the three diseases tested.

CONCLUSION

Elevencell vaccine titres were not inferior to the imported US vaccine in conferring protective titres against CDV, CPV and CAH, which confirms the efficacy of this product.

Seroprevalence of Canine Herpesvirus-1 in Breeding Dogs with or Without Vaccination in Northwest Italy

Canine herpesvirus-1 (CHV-1) can cause abortion and foetal and neonatal deaths in the bitch. The reactivation of latent infections with asymptomatic virus shedding represents a mechanism, whereby the virus can persist in a dog population. The aim of this study was to investigate the seroprevalence of CHV-1 in a population of breeding dogs in Piedmont, Northern Italy, and to investigate the distribution of herpesvirus vaccination. The study was carried out in 370 animals that were housed in 33 breeding kennels. Antibodies against CHV-1 in serum samples were measured by means of serum neutralization. Vaccination had been performed in 21.2% of the kennels and 8.4% of the dogs. The overall seroprevalence of CHV-1 was 50.3%. In ten kennels (30.3%), no seropositive dogs were identified. The percentage of seropositive dogs ranged from 7.1% to 100% in positive kennels. More than 40% of the seropositive dogs showed high titres. Sex had no significant effect on either seroprevalence or the category of the serum titre. The number of positive animals was significantly lower in the groups of prepuberal bitches and animals younger than 1.5 years. The majority of younger animals showed very high titres, suggesting recent contact with the virus. Our data show that CHV-1 is a common infection in breeding dogs in Piedmont. Vaccination is rarely performed but might be an option, because, although many animals of breeding age already show high antibody titres, seronegative pregnant bitches will be at high risk of contracting the infection due to viral circulation in kennels where the virus is enzootic.

Seroprevalence of viral and vector-borne bacterial pathogens in domestic dogs (Canis familiaris) in northern Botswana

BACKGROUND

Domestic dogs (Canis familiaris) have the potential to act as disease reservoirs for wildlife and are important sentinels for common circulating pathogens. Therefore, the infectious disease seroprevalence among domestic dogs in northern Botswana may be indicative of pathogen exposure of various wildlife species. The objective of this study was to assess the seroprevalence of Ehrlichia spp., Borrelia burgdorferi, Anaplasma spp., Dirofilaria immitis, canine adenovirus, canine parvovirus, and canine distemper virus in domestic dogs as proxies of disease prevalence in the local wildlife in the Okavango Delta region of Botswana. Statistical analysis assessed crude and factor-specific seroprevalence proportions in relation to age, sex, and geographical location as predictors of seropositivity. Logistic regression was used to identify adjusted predictors of seropositivity for each of the pathogens of interest.

RESULTS

Samples from 233 dogs in a total of seven locations in Maun, Botswana, and surrounding villages were collected and serologically analyzed. No dogs were seropositive for B. burgdorferi, while low seroprevalence proportions were observed for Anaplasma spp. (2.2%) and D. immitis (0.9%). Higher seroprevalence proportions were observed for the tick-borne pathogen Ehrlichia spp. (21.0%), and 19.7% were seropositive for canine adenovirus (hepatitis). The highest seroprevalence proportions were for canine parvovirus (70.0%) and canine distemper virus (44.8%). The predictors of seropositivity revealed that adults were more likely to be seropositive for canine adenovirus, canine distemper virus, and canine parvovirus than juveniles, and location was a risk factor for canine adenovirus, canine distemper virus, canine parvovirus, and Ehrlichia spp.

CONCLUSIONS

Results indicate that increasing tick control and vaccination campaigns for domestic dogs may improve the health of domestic animals, and potentially wildlife and humans in the Okavango Delta since viral and vector-borne bacterial pathogens can be transmitted between them.

Canine adenovirus type 1 causing neurological signs in a 5-week-old puppy

Background

Infectious canine hepatitis is a rarely encountered disease, that is caused by Canine Adenovirus-1. Clinical signs can vary dramatically, and neurological signs are rarely seen. Neurological manifestation of this disease is rarely reported in the veterinary literature.

Case presentation

A 5-week-old, male entire Husky cross puppy presented for a one-day history of abnormal neurological behaviour (circling, ataxia, vocalization and obtund mentation). The puppy was euthanized shortly after presentation due to rapid deterioration. Histopathology raised concerns for Canine Adenovirus 1 (CAdV-1) based on vasculitis in the brain and intranuclear inclusion bodies in endothelial cell and hepatocytes; immunohistochemistry on brain tissue confirmed CAdV-1 infection.

Conclusions

This report discusses possible routes of infection and manifestations of adenovirus infections causing neurologic signs. It also provides a timely reminder that CAdV-1 should be considered a differential in unvaccinated dogs that present with neurological signs. Further studies are required to better understand the neurotrophic tendencies of this virus.

The potential of the combined use of targeted type I interferon pathway inhibitors and oncolytic viruses to treat sarcomas

Replicating oncolytic viruses (OVs) are appealing, new, FDA-approved, therapeutic options for humans with head and neck cancers and melanomas. These treatments are not yet available for veterinary patients, but recent clinical trials have shown several OVs to be safe in dogs and cats. Specific viruses being used to treat sarcomas in dogs include modified canine adenovirus 2, myxoma virus, vesicular stomatitis virus and reovirus. In cats with vaccine-associated sarcomas, poxviruses have been injected postoperatively and a reduced rate of tumour recurrence was documented. To date, the response rates of canine and feline patients to OV therapy have been variable (as they are in people). Optimal methods of OV administration and dosing schedules continue to be evaluated. One way to improve outcomes of OV therapy in veterinary patients may be to use OVs in combination with other immunomodulatory therapies. This review discusses the potential utility of concurrent therapy with an OV and an inhibitor of the type I interferon pathway.

Cross-sectional investigation and risk factor analysis of community-acquired and hospital-associated canine viral infectious respiratory disease complex

Canine infectious respiratory disease complex (CIRDC) is associated with multiple factors. The possible transmission source can be via community-acquired infection (CAI) or hospital-associated infection (HAI), but the variable factors within these two routes are not well described. This study aimed to (i) investigate a cross-sectional incidence of canine respiratory viruses, including influenza (CIV), parainfluenza, distemper (CDV), respiratory coronavirus (CRCoV), adenovirus-2, and herpesvirus, in respiratory-diseased dogs, and (ii) analyze the possibly related risk factors. In total 209 dogs with respiratory illness, consisting of 133 CAI and 76 HAI dogs, were studied. Both nasal and oropharyngeal swabs were sampled from each dog and subjected for CIRDC virus detection using multiplex PCRs. Common six viruses associated with CIRDC were detected in both groups with CIV and CRCoV being predominantly found. Only CDV was significantly more prevalent in CAI than HAI dogs. Multiple virus detections were found in 81.2% and 78.9% of CAI and HAI dogs, respectively. Co-detection of CIV and CRCoV was represented the highest proportion and most often found with other CIRD viruses. Moreover, the clinical severity level was notably related to the age of infected dogs, but not to the vaccination status, sex and transmission route. Since healthy or control dogs were not included in this study, the prevalence of the CIRD virus infections could not be assessed.

The Causes of Canine Myocarditis and Myocardial Fibrosis Are Elusive by Targeted Molecular Testing: Retrospective Analysis and Literature Review

Myocarditis can cause death or permanent heart damage. As epidemiologic and etiopathologic data for canine myocarditis are lacking, we performed a retrospective study using nucleic acid extracted from archived (2007 to 2015) tissues from myocarditis cases and control dogs without myocardial lesions. Heart tissue from pediatric/juvenile and adult dogs was tested with a comprehensive panel of conventional and real-time polymerase chain reaction (PCR) assays targeting recognized agents of canine myocarditis based on a literature review and informed by the comparative epidemiology of human myocarditis. The PCR screen, which included canine parvovirus 2 (CPV-2), canine distemper virus, canine herpesvirus, Borrelia spp, West Nile virus, adenovirus, parainfluenza virus, pneumovirus, respiratory coronavirus, influenza virus, Bartonella spp, Rickettsia spp, Mycoplasma spp, and Neospora caninum, did not detect agents in 35 of 66 cases (53%; 95% confidence interval [CI], 41%-65%) and was frequently negative in adults (21/26); by comparison, agents were not detected in 27 of 57 controls (47%; 95% CI, 35%-60%). Canine distemper virus, herpesvirus, adenovirus, coronavirus, parainfluenza virus, Mycoplasma haemocanis, and N. caninum were occasionally detected in both cases and controls; thus, PCR detection was not considered to indicate causation. We previously reported that CPV-2 continues to be associated with myocarditis in young dogs despite widespread vaccination; in adults, CPV-2 was detected in 2 of 26 cases and 4 of 22 controls. As several agents were similarly detected in cases and controls, it is unclear if these are cardiopathogenic, incidental, or latent. West Nile virus was detected at the analytic limit in 1 adult case. We did not detect Borrelia spp, Bartonella spp, Rickettsia spp, or influenza A virus in the myocarditis cases. These data demonstrate the limitations of current targeted diagnostic tests and the need for additional research to identify unknown agents and develop testing strategies for canine myocarditis.

Novel Parvovirus Related to Primate Bufaviruses in Dogs

A novel protoparvovirus species, related genetically to human bufaviruses, was identified in dogs with respiratory signs. The canine bufavirus was distantly related to the well-known canine protoparvovirus, canine parvovirus type 2, sharing low amino acid identities in the nonstructural protein 1 (40.6%) and in the capsid protein 1 (33.4%). By screening collections of fecal, nasal, and oropharyngeal samples obtained from juvenile dogs (<1 year of age), canine bufavirus DNA appeared as a common component of canine virome. The virus was common in the stool samples of dogs with or without enteric disease and in the nasal and oropharyngeal swab samples of dogs with respiratory signs. However, the virus was not detected in nasal and oropharyngeal swab samples from animals without clinical signs.