Parvovirus infection in domestic companion animals

Update on Canine Parvoviral Enteritis

Canine parvoviral enteritis is one of the most common causes of morbidity and mortality in young dogs worldwide. The virus is endemic in the environment and can be infective to unvaccinated or poorly vaccinated dogs. Standard in-patient therapies include use of antiemetics, intravenous fluids, antibiotics and provision of enteral nutrition. The use of antiviral drugs, immunomodulators and monoclonal antibody therapy are newer possibilities that may potentially improve outcome. Outpatient therapy also remains a viable possibility for treatment if financial constraints exist.

Known and novel parvoviruses identified in domestic pigeons

BACKGROUND

Parvoviridae is a family of single-stranded linear DNA viruses whose members infect both vertebrate and invertebrate species of animals, causing diseases of various systems and often associated with pathology of the gastrointestinal tract. Additionally, parvoviruses are known to induce illnesses causing diarrhea in various avian species as well; however, data on their occurrence and pathology in pigeons is scarce.

RESULTS

In this study, we developed molecular biology methods to detect and quantify parvovirus genetic material in samples acquired from racing pigeons of different health status. Our intention was to determine a connection between the presence of the virus and the occurrence of clinical signs in sampled birds. The results of quantitative analysis indicate no direct association of parvoviruses with the manifestation of enteric disease in pigeons. High-throughput sequencing was performed on samples testing positive in quantitative PCR with TaqMan probe and in digital droplet PCR. It allowed us to assemble two coding-complete pigeon parvovirus genomes, one belonging to new species and referred to as pigeon parvovirus 2, and the second which is a member of species Aveparvovirus columbid1. Additionally, we analyze two coding-complete genomic sequences acquired from pigeon feces in USA, one representing species Aveparvovirus columbid1 and one being a member of Chaphamaparvovirus genus in Hamaparvovirinae subfamily.

CONCLUSIONS

This is the first report of parvovirus in pigeons outside Asia. The findings of our research emphasize the need to further explore the poorly understood biology and pathology of pigeon parvoviruses.

Molecular characterization of full-length VP2 gene of canine parvovirus type 2 strains circulating in Egypt 2019-2021

Canine parvovirus type 2 (CPV-2) is a major cause of fatal gastroenteritis and myocarditis in puppies of domestic and wild carnivores. CPV-2 has accumulated changes over time lead to the emergence of three antigenic variants CPV-2a, CPV-2b, and CPV-2c. VP2 is the major capsid protein that determines virus antigenicity, and host range. Although the three CPV-2 variants were previously identified in Egypt, most reports covered a restricted geographic region and/or time period, and only analyzed partial fragments of VP2 gene. Therefore, this study was designed to test 100 rectal swabs collected from 7 Egyptian governorates between 2019 and 2021 for CPV-2 using PCR. A total of 65 positive samples were identified, mostly in pure dog breeds of young age. The three variants co-circulated in 2019, while CPV-2b was not detected in 2020 and 2021. The frequency of CPV-2b and CPV-2c was higher in 2019 and 2021, respectively. Analysis of CPV-2 full-length VP2 gene sequence from 19/65 positive samples has identified four common amino acid substitutions F267Y, S297A, A300G, Y324I, which are characteristic for the new CPV-2 variants currently circulating worldwide. Unique substitutions including A5G, G36R, V38E, Q370R, and G392V were recognized in certain samples, and appears to have distinct effect on receptor binding, nuclear translocation, and inter-species transmission. Phylogenetic analysis showed separation of CPV-2 strains into two clades. All strains of this study were classified in clade I with Asian strains. In conclusion, this study provides updated comprehensive molecular analysis of CPV-2 variants in Egypt.

Epidemiology, molecular prevalence and prevention on canine parvovirus in India: A review

Canine parvovirus (CPV) is a highly contagious and lethal virus that causes severe gastroenteritis and myocarditis in young dogs. In 1978, CPV has rapidly spread worldwide, resulting in outbreaks and high morbidity rates among dog populations. Over a decade, CPV has undergone genetic changes, leading to the emergence of different genotypes (CPV-2a, CPV-2b, and CPV-2c), which have expanded its host range to include cats and tissue culture cells. This review focuses on CPV-2 outbreaks in India from 2010 to 2023, analyzing gene lengths covering 274-438 amino acids in the VP2 gene which are collected from the NCBI database to investigate CPV epidemiology and diversity. The study highlighted substantial differences in seroprevalence over the period for CPV-2 (7%), CPV-2a (45%), CPV-2b (12%), and CPV-2c (36%). Our study found significant seroprevalence differences among CPV variants, with CPV-2a being the most prevalent, underscoring the need for effective diagnostic and preventive strategies.

A mixed-methods approach utilising electronic health records to examine antimicrobial prescription surrounding gastrointestinal clinical presentations in dogs and cats

Introduction

Systemically-administered antimicrobials are often prescribed in canine and feline gastrointestinal clinical presentations. Responsible use of antimicrobials, particularly those considered Highest Priority Critically Important Antimicrobials (HPCIAs) is vital to tackle antimicrobial resistance. Although practice-level prescription guidance is available, further strategies based on a greater understanding of antimicrobial prescription at the population-level are needed. Here, we used a mixed-methods approach, harnessing veterinary electronic health records (EHRs) to characterise the use of antimicrobials in canine and feline gastrointestinal presentations, and to explore justification and reasoning around antimicrobial prescribing, particularly of HPCIAs.

Methods

This observational study used 23,337 EHRs complemented with veterinary practitioner-completed questionnaires, from canine and feline gastrointestinal consultations from 225 volunteer UK veterinary practices between April 2014 and September 2018.

Results

A total of 83.4% (95% confidence interval (CI) 82.6-84.3) gastrointestinal presentations were reported as mild, with non-haemorrhagic diarrhoea and vomiting the most frequently reported clinical signs. Systemically-administered antimicrobials occurred in 28.6% of canine (95% CI 26.9-30.3) and 22.4% of feline (95% CI 20.4-24.4) gastrointestinal consultations, with HPCIA prescription occurring more frequently in cats. Results of multivariable analysis showed the presence of non-haemorrhagic diarrhoea (canine Odds Ratio (OR) 2.1, 95% CI 1.9-2.3; feline OR 1.8, 95% CI 1.5-2.1), haemorrhagic diarrhoea (canine OR 4.2, 95% CI 3.8-4.7; feline OR 3.1, 95% CI 2.4-3.8), and moderate/severe presentations (canine OR 1.9, 95% CI 1.7-2.8; feline OR 2.0, 95% CI 1.7-2.5) were positively associated with receiving a systemically-administered antimicrobial. Thematic analysis of clinical narrative content of 516 gastrointestinal consultations where HPCIAs were prescribed allowed the identification of ten factors underpinning reasoning or decision-making for HPCIA prescription: perceived animal/owner compliance; owner's expectations; perceived risk of infection; clinical signs; recent clinical history; perceived positive previous response to antimicrobial therapy; geriatric patients and euthanasia; concomitant conditions; diagnostic testing and the behavioral trend to trial antimicrobial therapy empirically in gastrointestinal cases. No explicit justification for HPCIA prescription was recorded in 77% of cases.

Discussion

Improving recorded justification represents a clear target for stewardship programmes. By utilising a complementary mixed-methods approach to EHRs, this study unlocks previously untapped data recorded within EHRs. These results can help inform targeted interventions, contributing towards enhanced antimicrobial stewardship.

The Structures and Functions of Parvovirus Capsids and Missing Pieces: the Viral DNA and Its Packaging, Asymmetrical Features, Nonprotein Components, and Receptor or Antibody Binding and Interactions

Parvoviruses are among the smallest and superficially simplest animal viruses, infecting a broad range of hosts, including humans, and causing some deadly infections. In 1990, the first atomic structure of the canine parvovirus (CPV) capsid revealed a 26-nm-diameter T=1 particle made up of two or three versions of a single protein, and packaging about 5,100 nucleotides of single-stranded DNA. Our structural and functional understanding of parvovirus capsids and their ligands has increased as imaging and molecular techniques have advanced, and capsid structures for most groups within the Parvoviridae family have now been determined. Despite those advances, significant questions remain unanswered about the functioning of those viral capsids and their roles in release, transmission, or cellular infection. In addition, the interactions of capsids with host receptors, antibodies, or other biological components are also still incompletely understood. The parvovirus capsid's apparent simplicity likely conceals important functions carried out by small, transient, or asymmetric structures. Here, we highlight some remaining open questions that may need to be answered to provide a more thorough understanding of how these viruses carry out their various functions. The many different members of the family Parvoviridae share a capsid architecture, and while many functions are likely similar, others may differ in detail. Many of those parvoviruses have not been experimentally examined in detail (or at all in some cases), so we, therefore, focus this minireview on the widely studied protoparvoviruses, as well as the most thoroughly investigated examples of adeno-associated viruses.

Feline Parvovirus Lethal Outbreak in a Group of Adult Cohabiting Domestic Cats

Feline panleukopenia is a highly contagious and often fatal disease in cats. The virus, known as feline panleukopenia virus (FPV), primarily affects kittens and unvaccinated cats. It is transmitted through contact with infected cats or their bodily fluids, as well as contaminated objects and environments. The diagnosis of FPV infection can be confirmed through a combination of clinical signs, blood tests, and fecal testing. Prevention through vaccination is recommended for all cats. This case report describes an outbreak of feline panleukopenia in a group of unvaccinated domestic cats that resulted in acute mortality. The lesions were evaluated using histopathology, and the specific viral strain was characterized using molecular techniques. The clinical course of the outbreak was peracute, with a hemorrhagic pattern and 100% of lethality. The observed clinical-pathological pattern was unusual; nevertheless, molecular studies did not highlight peculiar genomic features of the parvovirus isolate. The outbreak affected 3 out of 12 cats in a very short time. However, the prompt application of biosecurity measures and vaccination resulted in an effective interruption of virus spread. In conclusion, we could assume that the virus found the ideal conditions to infect and replicate at high titers, resulting in a particularly aggressive outbreak.

Genomic characterization and Phylogenetic evolution of the canine parvoviruses in Iranian dogs, a nationwide study: CPV evolutionary analysis in Iran

Canine Parvo Virus 2(CPV-2) culminated in lots of fatalities in domestic dogs since its emergence in 1978. Mainly, it is responsible for severe hemorrhagic diarrhea, vomiting, and dehydration. CPV-2 has three main variants known 2a, 2b, and 2c. Due to the necessity of monitoring the evolutionary parameters of the virus, and also the lack of comprehensive study of CPV2 in Iran, this study is done for the first time in this country not only to characterize Iranian CPV genomes but also to study the evolutionary parameters and phylodynamics of CPV. The phylogenetic trees were constructed using the Maximum Likelihood (ML) method. By the use of the Bayesian Monte Carlo Markov Chain (BMCMC) method, evolutionary analysis and phylodynamics of the virus were investigated. Phylogenetic results showed that all Iranian isolates were classified in the CPV-2a variant. The central part of Iran was suggested to be the origin of the virus, especially the Alborz province. Before its prevalence throughout the country, the virus circulated in the central part, in Thran, Karaj, and Qom. Mutational analysis showed a positive selection pressure of CPV-2a. Investigating the evolutionary parameters of the virus proposed 1970 to be the date of birth of the virus, with a 95% credible interval between 1953 and 1987. The effective number of infections increased dramatically from 2012 to 2015, then faced a slightly decreasing trend from 2015 to 2019. A considerable up warding pattern was witnessed from the middle of 2019, which can be taken as a concern about the risk of vaccination failure.

[Parvovirus infections in cats in animal shelters]

Due to widespread vaccination programs against feline panleukopenia virus (FPV), the disease associated with this virus infection, feline panleukopenia, is rarely seen in privately owned cats in Germany. In contrast, the situation in animal shelters differs due to the constant intake of new cats that are often unprotected. In such facilities, panleukopenia outbreaks are common and often accompanied by a high number of fatalities. Due to the high contagiosity of the virus, some shelters do not accept cats with clinical signs suspicious for panleukopenia, since these animals can pose a risk to the shelter population. However, not only cats with panleukopenia shed parvovirus, but also healthy, asymptomatic cats can and thus contribute to risk of infection. Nevertheless, the risk for panleukopenia outbreaks in animal shelters can be reduced by rigorous outbreak management. This includes hygiene measures using correctly applied cleaning and disinfection protocols, quarantine measures, separate isolation units, as well as specific prophylactic measures, such as identification of infected animals and immunization of susceptible groups.

Assessment of Hematological and Serum Biochemistry Parameters in Dogs with Acute Diarrhea Due to Different Etiologies

Acute diarrhea (AD) has a complex etiology and may lead to life-threatening conditions. Hematological and serum biochemistry analyses can be useful for a differential diagnosis and for determining the severity of diarrhoea. Dogs with AD (n=72) were divided into Isospora (n=18), Toxocara (n=18), Parvoviral Enteritis (n=18), and Dietary Diarrhea (n=18) subgroups following clinical and laboratory examinations. The study aimed to evaluate the diagnostic value of certain hematological and serum biochemistry parameters. Clinical examinations, rapid diagnostic tests, complete blood count (CBC), and biochemical analyses were performed. White blood cell count (WBC), granulocyte, and mean hemoglobin concentration (MCH) levels were lower in the Parvoviral Enteritis Group compared with the other groups (p<0.01). Isospora, Parvoviral Enteritis, and Toxocara groups had lower glucose and total protein, and higher creatinine levels than those of the Control and Dietary Diarrhea groups (p<0.0001). The albumin level of the Dietary Diarrhea Group was higher compared with the other groups (p<0.0001). Parvoviral Enteritis and Isospora groups had higher ALP levels than those of the other groups (p<0.0001). Blood urea nitrogen (BUN), alanine aminotransferase (ALT), C-reactive protein (CRP), and cholesterol levels were determined to be highest in the Parvoviral Enteritis Group (p<0.0001). The total bilirubin level was higher in Parvoviral Enteritis and Toxocara groups compared with the Control, Isospora, and Dietary Diarrhea groups (p<0.0001). As a result, it was concluded that in cases of AD due to parvoviral enteritis and Toxocara canis, serum biochemistry abnormalities may be more severe, can provide more clinical information than CBC, and can be useful in forming a differential diagnosis list, especially in triage.

A canine-derived chimeric antibody with high neutralizing activity against canine parvovirus-2

Canine parvovirus-2 (CPV-2) infection causes serious multisystemic disease in dogs and many animal species worldwide. Previously, a monoclonal antibody (MAb) of CPV-2, 10H4, showed high neutralizing activity and therapeutic effect against CPV-2 in dogs. However, the application of mouse MAb is limited in other animals due to immune rejection. Here, the variable regions of the heavy and light chains of 10H4 were cloned and ligated with constant canine antibody regions to produce a canine-derived chimeric MAb 11D9, in a CHO-S cell expression system. The cell supernatant of the CHO cell line 11D9 exhibited a HI titer of 1:2560 against all the variants of CPV-2 (new CPV-2a, new CPV-2b, and CPV-2c), and had the same average neutralization titer as the new CPV-2a (1:11,046.5) and new CPV-2b (1:11,046.5) variants, which was slightly higher than that of CPV-2c variants (1:10,615.7). In animal experiment, the treatment of chimeric MAb 11D9 had a high therapeutic effect in beagles infected with the new CPV-2a. Overall, the canine-derived chimeric MAb 11D9 produced by CHO-S cells showed a high HI and neutralization titer against CPV-2 and the therapeutic effects against the new CPV-2a in beagles, providing potential for the prevention or treatment of CPV-2 infections in dogs.

A canine-derived chimeric MAb 11D9 was produced by CHO cell lines.

The MAb 11D9 exhibited high HI and neutralization titers against new CPV-2 variants.

The MAb 11D9 had a high therapeutic effect in beagles infected with the new CPV-2a variant.

Feline Panleukopenia Outbreaks and Risk Factors in Cats in Animal Shelters

(1) Background: This study aimed to determine the risk factors for outbreaks of feline panleukopenia in shelters. (2) Methods: Four shelters (A−D) with 150 cats were included. Fecal samples were analyzed by parvovirus real-time polymerase chain reaction (qPCR), including culture and sequencing of qPCR-positive samples. Information on cats, husbandry, hygiene, and infection management was evaluated to determine risk factors for feline panleukopenia and parvovirus shedding by logistic regression. (3) Results: Feline panleukopenia occurred in 28.0% (42/150) of cats (0 in shelter D). Shedding was found in 48.7% (73/150) (A: 21/73; B: 29/73; C: 7/73; D: 16/73). Of 73 qPCR-positive fecal samples, 65.8% (48/73) were culture-positive; sequencing revealed feline panleukopenia virus (FPV) isolates in 34/48 samples and vaccine virus isolate in 14/48; canine parvovirus was not detected. Presence of feline panleukopenia was significantly more likely in cats from shelter A (p < 0.05), unvaccinated cats (p < 0.001), and young cats (4 weeks to 2 years; p = 0.008). Parvovirus shedding was significantly more common in young cats (p < 0.001), cats with feline panleukopenia (p = 0.033), and group-housed cats (p = 0.025). (4) Conclusions: Vaccination is the most important measure to reduce the risk of feline panleukopenia in shelters. Risk of parvovirus shedding is especially high in young, group-housed cats.

Serum cobalamin concentrations in dogs infected with canine parvoviral enteritis

OBJECTIVE

To compare the serum cobalamin concentrations in canine parvovirus (CPV)-infected dogs with those of healthy control dogs.

Animals

45 dogs with CPV enteritis and 17 healthy age-matched control dogs.

Procedures

Infection was confirmed by visualization of CPV-2 through fecal electron microscopy. All dogs received supportive care. Serum samples taken at admission were used to determine cobalamin, C-reactive protein, and albumin concentrations.

Results

Serum cobalamin concentrations were significantly lower in the CPV-infected group (median [interquartile range], 173 pmol/L [< 111 to 722 pmol/L]) than in healthy control dogs (379 pmol/L [193 to > 738 pmol/L). There was no association between cobalamin concentration and C-reactive protein or albumin concentration.

Clinical Relevance

While hypocobalaminemia was common in CPV-infected dogs, the clinical relevance of this finding remains to be determined. Studies assessing markers of cellular cobalamin deficiency in dogs with CPV infection appear warranted.

High-throughput sequencing technologies in the detection of livestock pathogens, diagnosis, and zoonotic surveillance

Increasing globalization, agricultural intensification, urbanization, and climatic changes have resulted in a significant recent increase in emerging infectious zoonotic diseases. Zoonotic diseases are becoming more common, so innovative, effective, and integrative research is required to better understand their transmission, ecological implications, and dynamics at wildlife-human interfaces. High-throughput sequencing (HTS) methodologies have enormous potential for unraveling these contingencies and improving our understanding, but they are only now beginning to be realized in livestock research. This study investigates the current state of use of sequencing technologies in the detection of livestock pathogens such as bovine, dogs (Canis lupus familiaris), sheep (Ovis aries), pigs (Sus scrofa), horses (Equus caballus), chicken (Gallus gallus domesticus), and ducks (Anatidae) as well as how it can improve the monitoring and detection of zoonotic infections. We also described several high-throughput sequencing approaches for improved detection of known, unknown, and emerging infectious agents, resulting in better infectious disease diagnosis, as well as surveillance of zoonotic infectious diseases. In the coming years, the continued advancement of sequencing technologies will improve livestock research and hasten the development of various new genomic and technological studies on farm animals.

Molecular diversity of the VP2 of Carnivore protoparvovirus 1 (CPV-2) of fecal samples from Bogotá

BACKGROUND

Carnivore protoparvovirus 1, also known as canine parvovirus type 2 (CPV-2), is the main pathogen in hemorrhagic gastroenteritis in dogs, with a high mortality rate. Three subtypes (a, b, c) have been described based on VP2 residue 426, where 2a, 2b, and 2c have asparagine, aspartic acid, and glutamic acid, respectively.

OBJECTIVES

This study examined the presence of CPV-2 variants in the fecal samples of dogs diagnosed with canine parvovirus in Bogotá.

METHODS

Fecal samples were collected from 54 puppies and young dogs (< 1 year) that tested positive for the CPV through rapid antigen test detection between 2014-2018. Molecular screening was developed for VP1 because primers 555 for VP2 do not amplify, it was necessary to design a primer set for VP2 amplification of 982 nt. All samples that were amplified were sequenced by Sanger. Phylogenetics and structural analysis was carried out, focusing on residue 426.

RESULTS

As a result 47 out of 54 samples tested positive for VP1 screening, and 34/47 samples tested positive for VP2 980 primers as subtype 2a (n = 30) or 2b (n = 4); subtype 2c was not detected. All VP2 sequences had the amino acid, T, at 440, and most Colombian sequences showed an S514A substitution, which in the structural modeling is located in an antigenic region, together with the 426 residue.

CONCLUSIONS

The 2c variant was not detected, and these findings suggest that Colombian strains of CPV-2 might be under an antigenic drift.

Chaphamaparvovirus antigen and nucleic acids are not detected in kidney tissues from cats with chronic renal disease or immunocompromised cats

Chronic kidney disease (CKD) is a common cause of morbidity and mortality in domestic cats, but the cause is still largely elusive. While some viruses have been associated with this disease, none have been definitively implicated as causative. Recently, Rodent chaphamaparvovirus 1 was recognized as the cause of murine inclusion body nephropathy, a disease reported for over 40 years in laboratory mice. A novel virus belonging to the same genus, Carnivore chaphamaparvovirus 2, was recently identified in the feces of cats with diarrhea. The goal of this study was to investigate the possible role of chaphamaparvoviruses including members of Rodent chaphamaparvovirus 1 and Carnivore chaphamaparvovirus 2 in the development of feline CKD. The presence of these viruses was retrospectively investigated in formalin-fixed paraffin-embedded feline kidney samples using polymerase chain reaction, in situ hybridization, and immunohistochemistry. Cats were divided into 3 groups: normal (N = 24), CKD (N = 26), and immunocompromised (N = 25). None of the kidney tissues from any of the 75 cats revealed the presence of chaphamaparvovirus DNA, RNA, or antigen. We conclude that viruses belonging to the chaphamaparvovirus genus are unlikely to contribute to the occurrence of feline CKD.

[Prophylaxis of canine parvovirosis - Part 2: Vaccines]

Vaccination is still the most effective measure to prevent canine parvovirosis. Therefore, vaccines against canine parvovirus (CPV) infection are considered core vaccines. Modified life vaccines (MLV) have been proven to be very effective and safe, since they are characterized by early onset (within a few days after vaccination) and long duration of immunity (several years). MLV do not contain adjuvants; they are also advantageous in terms of possessing less allergenic and toxic properties. Therefore, MLV are widely used as first line vaccines. In Germany and in most other European countries, only MLV are available on the market. MLV contain CPV-2 or (less often) CPV-2b and offer cross-protection against the variants CPV-2a, -2b, -2c that are relevant for dogs in the field. Revaccination with MLV should be performed in 3-year-intervals or longer intervals (only in case of lacking antibodies) even if the licensed MLV is registered for re-vaccination intervals of 1 or 2 years. MLV should only be administered to healthy dogs older than 4 to 6 weeks of age. A possible disadvantage of MLV is its interference with the diagnosis of a CPV infection.

Comparison of pathological changes in the study of dogs affected by parvoviral enteritis and intestinal yersiniosis

Aim of the study: to examine the pathological changes in dogs that died due to confirmed intestinal yersiniosis and parvoviral enteritis and establish trends for characteristic organ lesions for both diseases in comparison, then evaluate our findings with the existing published material of sufficient evidence quality regarding differential postmortem diagnosis of spontaneous intestinal yersiniosis and parvoviral enteritis in dogs. Materials and methods: the study examined the cases of 25 dogs from 2 month to 1.3 y.o. of various breed, gender that died due to either confirmed Canine parvoviral enteritis (CPV) infection or intestinal yersiniosis and subsequently divided into two groups based on their diagnosis. The definitive diagnosis has been confirmed by performing rapid ELISA diagnostics (SensPERT®, VetAll Laboratories, Kyunggi-Do, Korea) for CPV and serological tests for Y. enterocolitica sera AT were performed using yersiniosis antigens from the "Component set for serological diagnosis of animal yersiniosis" (Kharkiv, NSC IEKVM, TS 46.15.091-95) in accordance with the "Interim guidelines for the use of a set of components for serological diagnostics". A dilution of 1: 200 has been considered as the diagnostic titer. After the definitive diagnosis had been confirmed, the animals were divided into two groups, depending on diagnosis: CPV (n=14) or IY (n=11). The autopsies of twenty randomly (10 from each group) selected dog corpses have been conducted utilizing standard methodology. Results: according to the results of autopsy of dogs afflicted by CPV, the main pathological changes were found in the small intestine – catarrhal-desquamative inflammation (in 100 % of cases), serous-hemorrhagic mesenteric lymphadenitis (90 %) large intestine (70 %) in the stomach (60 %), in the liver (50 %), in other organs – less than 40 percent of cases and most notably caused lung damage (edema and local atelectasis) in 90 % of the animals in the study, which was not the case for intestinal yersiniosis with only 20 % incidence of lung damage. Conclusions: Spontaneous intestinal yersiniosis in dogs was pathologically manifested by pronounced catarrhal-desquamative processes mainly in the stomach and small intestine (70, 100 and 80 % of cases, respectively), inflammation of the mesenteric lymph nodes (90 %) and large intestine (80 %), dystrophy and congestive processes in the liver (80 %). Low incidence and type of lung damage (congestive hyperemia in 20 % of reviewed cases compared to 90 % of local atelectasis add edema in CPV group) was noteworthy. Cases of 25 animals that died due to either confirmed CPV or Y. enterocolitica infection were analyzed, and 20 animal corpses were autopsied during study. Dogs that died from intestinal yersiniosis had significantly higher frequency of pathological findings in kidney (200 %) and liver (60 %) in particular. Changes in stomach and large intestine were also more frequent. At the same time, we observed a lower frequency of pathological changes in spleen (33 % lower), heart (25 % lower) and the lowest frequency was in lungs (77 % lower) presented by edema and local atelectasis in animals afflicted by yersiniosis compared to CPV. Incidence and manifestation of pathological findings was mesenteric lymph nodes and abdominal cavity were similar, and could not be considered during posthumous diagnostics.

Prognostic values of physical and hematological parameters of dogs naturally infected with parvovirus PVC-2: retrospective study of 103 cases

ABSTRACT Canine parvovirosis is a high mortality disease with acute clinical picture. However, there are few available resources to help stablish prognosis accurately. This study aimed to determine the prognostic threshold values for vital and hematological parameters of dogs naturally infected by the Carnivore protoparvovirus 1 (CPV). A retrospective study of 103 canine parvovirosis cases was carried out. Twenty seven percent of these (28/103) died, 96% (27/28) of which within the first four days of hospitalization. Deceased animals had significantly higher median values for heart (HR) and respiratory (f) rates, as well as significantly lower systolic blood pressure (SBP) than survivors. Severely leukopenic animals (<1,000 cells/μL), had a significantly higher mortality rate (68%, n=13) compared to that of other patients (P<0.0007). Animals with at least two of the following findings: severe hypotension (SBP< 90mmHg), tachycardia (HR > 150 bpm) and leukopenia, represented 34% (34/101) of the cases and had a survival rate of 29% (10/34), while animals with at most one of these parameters represented 66% (67/101) and had a survival rate of 94% (63/67). The presence of two or three abnormal parameters was significantly related to the higher death risk among dogs with parvovirosis (P<0.0001).

Update on Canine Parvoviral Enteritis

Canine parvoviral enteritis is one of the most common causes of morbidity and mortality in dogs worldwide. Tests can detect viral antigen in feces, and characteristic decreases in total leukocyte, neutrophil, and lymphocyte counts can increase the index of suspicion in affected cases and can be used to prognosticate morbidity and mortality. The standard of care for infected animals includes IV crystalloid and sometimes colloid fluids, antiemetics, broad-spectrum antibiotics, and early enteral nutrition. Vaccination induces protective immunity in most dogs. Vaccination, along with limiting exposure in young puppies, is the most effective means of preventing parvoviral enteritis in dogs.

Carnivore Protoparvovirus-1 Associated With an Outbreak of Hemorrhagic Gastroenteritis in Small Indian Civets

Carnivore protoparvovirus-1 (CPPV-1) infection has been reported frequently in both domestic and wildlife species including wild carnivores. Fifty-five captive small Indian civets (Viverricula indica), farmed for perfume production in Eastern Thailand, showed clinical signs of acute bloody diarrhea, anorexia, vomiting, circling, and seizures. The disease spread within the farm and resulted in the death of 38 of the 55 civets (69% mortality) within a month. Fecal swabs were collected from the 17 surviving civets, and necropsy was performed on 7 of the dead civets. Pathologic findings were severe hemorrhagic gastroenteritis with generalized lymphadenopathy. CPPV-1 was identified in both fecal swabs and postmortem samples by species-specific polymerase chain reaction. Further whole-gene sequencing and restriction fragment length polymorphism analysis suggested feline panleukopenia virus (FPV) as the causative agent. The viral tropism and tissue distribution were confirmed by immunohistochemistry, with immunolabeling in the cytoplasm and nucleus of small intestinal crypt epithelial cells, villous enterocytes, histiocytes in lymphoid tissues, myenteric nerve plexuses, and cerebral and cerebellar neurons. Phylogenetic analysis of civet-derived CPPV-1 indicated a genetic similarity close to the FPV HH-1/86 strain detected in a jaguar (Panthera onca) in China. To our knowledge, this mass die-off of civets is the first evidence of disease associated with CPPV-1 infection in the subfamily Viverrinae. These findings support the multi-host range of parvovirus infection and raises awareness for CPPV-1 disease outbreaks in wildlife species.

Detection of canine parvovirus types 2b and 2c in canine faecal samples contaminating urban thoroughfares in Brazil

Canine parvovirus type 2 (CPV-2) is a highly contagious virus that causes acute gastroenteritis in dogs all over the world. Because of its stability in the environment, CPV-2 can remain infective for a long time, especially if protected in organic matter. To demonstrate CPV-2's potential as an environmental hazard for nonimmunized susceptible hosts, we investigated 50 faecal samples collected from public areas in a municipality of Paraná state, Brazil. Seven samples tested positive for CPV by a PCR assay targeting the partial VP2 gene, with three strains being confirmed as CPV-2b variant and one as CPV-2c variant by sequence analysis. These findings were supported by phylogenetic analysis, and the species identity of faecal samples source was confirmed by canine mitochondrial DNA amplification and sequencing. Our results demonstrate the presence of CPV in canine faeces contaminating urban thoroughfares and reinforce the importance of environmental control to reduce the potential exposure risks to susceptible hosts.

Inhibitory Effects of Antiviral Drug Candidates on Canine Parvovirus in F81 cells

Canine parvovirus (CPV) is a common etiological agent of acute enteritis, which occurs globally in domestic and wild carnivores. Despite the widespread use of inactivated or live attenuated vaccines, the emergence of antigenic variants and the influence of maternal antibodies have raised some concerns regarding the efficacy of commercial vaccines. While no specific antiviral therapy for CPV infection exists, the only treatment option for the infection is supportive therapy based on symptoms. Thus, there is an urgent medical need to develop antiviral therapeutic options to reduce the burden of CPV-related disease. In this study, a cytopathic effect (CPE)-based high-throughput screening assay was used to screen CPV inhibitors from a Food and Drug Administration (FDA)-approved drug library. After two rounds of screening, seven out of 1430 screened drugs were found to have >50% CPE inhibition. Three drugs—Nitazoxanide, Closantel Sodium, and Closantel—with higher anti-CPV effects were further evaluated in F81 cells by absolute PCR quantification and indirect immunofluorescence assay (IFA). The inhibitory effects of all three drugs were dose-dependent. Time of addition assay indicated that the drugs inhibited the early processes of the CPV replication cycle, and the inhibition effects were relatively high within 2 h postinfection. Western blot assay also showed that the three drugs had broad-spectrum antiviral activity against different subspecies of three CPV variants. In addition, antiapoptotic effects were observed within 12 h in Nitazoxanide-treated F81 cells regardless of CPV infection, while Closantel Sodium- or Closantel-treated cells had no pro- or antiapoptotic effects. In conclusion, Nitazoxanide, Closantel Sodium, and Closantel can effectively inhibit different subspecies of CPV. Since the safety profiles of FDA-approved drugs have already been extensively studied, these three drugs can potentially become specific and effective anti-CPV drugs.

Survival estimates and outcome predictors for shelter cats with feline panleukopenia virus infection

OBJECTIVE To determine survival estimates and outcome predictors for shelter cats with feline panleukopenia virus (FPV) infection. DESIGN Retrospective cohort study. ANIMALS 177 shelter cats with FPV infection. PROCEDURES Medical records of cats treated for FPV infection from 2011 through 2013 were reviewed to collect information pertaining to signalment; history; results of physical examination, CBC, serum biochemical analysis, and blood gas analysis; and treatments (antimicrobials, antiparasitics, antivirals, antiemetics, analgesics, crystalloid or colloid solutions, and blood products). Survival time and outcome predictors were determined by means of Kaplan-Meier estimation, logistic regression, and mixed-model ANOVA. RESULTS Median survival time after hospital admission was 3 days; 20.3% (36/177) of cats survived to discharge from the hospital. Risk of nonsurvival was greater in cats with (vs without) signs of lethargy, rectal temperature < 37.9°C (I00.2°F), or low body weight at hospital admission. Lower (vs higher) leukocyte count on days 3,4, and 7 of hospitalization, but not at admission, was associated with nonsurvival. Amoxicillin-clavulanic acid, antiparasitics, and maropitant but not interferon-ω were associated with survival, whereas glucose infusion was associated with nonsurvival. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that FPV infection carried a poor prognosis for shelter cats. Several variables measured at admission or during hospitalization were associated with outcome. Remarkably and contrary to the existing literature, leukopenia at admission had no association with outcome, possibly owing to early prevention of complications.

Transmission ecology of canine parvovirus in a multi-host, multi-pathogen system

Understanding multi-host pathogen maintenance and transmission dynamics is critical for disease control. However, transmission dynamics remain enigmatic largely because they are difficult to observe directly, particularly in wildlife. Here, we investigate the transmission dynamics of canine parvovirus (CPV) using state-space modelling of 20 years of CPV serology data from domestic dogs and African lions in the Serengeti ecosystem. We show that, although vaccination reduces the probability of infection in dogs, and despite indirect enhancement of population seropositivity as a result of vaccine shedding, the vaccination coverage achieved has been insufficient to prevent CPV from becoming widespread. CPV is maintained by the dog population and has become endemic with approximately 3.5-year cycles and prevalence reaching approximately 80%. While the estimated prevalence in lions is lower, peaks of infection consistently follow those in dogs. Dogs exposed to CPV are also more likely to become infected with a second multi-host pathogen, canine distemper virus. However, vaccination can weaken this coupling, raising questions about the value of monovalent versus polyvalent vaccines against these two pathogens. Our findings highlight the need to consider both pathogen- and host-level community interactions when seeking to understand the dynamics of multi-host pathogens and their implications for conservation, disease surveillance and control programmes.

Lymphoplasmacytic Meningoencephalitis and Neuronal Necrosis Associated With Parvoviral Infection in Cats

Neurologic manifestations other than cerebellar hypoplasia are rarely associated with feline panleukopenia virus (FPV) infection in cats. Here the authors describe lymphoplasmacytic meningoencephalitis and neuronal necrosis in 2 cats autopsied after exhibiting ataxia and nystagmus. Gross changes consisted of cerebellar herniation through the foramen magnum, with flattening of cerebrocortical gyri and narrowing of sulci. Histologically, lymphoplasmacytic meningoencephalitis, extensive neuronal necrosis, and neuroaxonal degeneration with digestion chambers were present in the telencephalon and brain stem in both cats. Frozen brain tissue of both cats was positive for parvoviral antigen via fluorescent antibody testing, and formalin-fixed, paraffin-embedded tissue sections of brain were immunoreactive for parvovirus antigen and positive for parvoviral DNA on in situ hybridization. Frozen brain tissue from 1 case was positive for parvovirus NS1 and VP2 genes using conventional polymerase chain reaction, and subsequent DNA sequencing and phylogenetic analysis revealed that the viral strain was a FPV. Reverse transcription quantitative polymerase chain reaction on formalin-fixed, paraffin-embedded brain tissue revealed high levels of parvovirus in both cases, supporting an acute and active viral infection. Although rare, FPV infection should be considered in cases of lymphoplasmacytic meningoencephalitis and neuronal necrosis in cats.

Serosurvey of rabies virus, canine distemper virus, parvovirus, and influenza virus in military working dogs in Korea

Rabies virus (RABV), canine distemper virus (CDV), canine parvovirus type-2 (CPV-2), and canine influenza A virus (CIV) are important contagious pathogens in canine populations. To assess post-vaccination immunity against RABV, CDV and CPV-2, and serological evidence of exposure to influenza A virus in military working dogs (MWDs) in Korea, we tested blood samples of 78 MWDs by fluorescent antibody virus neutralization (FAVN) for RABV, and by commercially available enzyme-linked immunosorbent assay (ELISA) for CDV, CPV-2, and CIV. Korean MWDs had high antibody-positive rates against RABV (97.4%, ≥0.5 IU/ml), CDV (94.8%), and CPV (100%). All dogs tested seronegative (0/78; 0%) for influenza A virus. Two 1-year-old dogs stationed in known rabies outbreak areas (Gangwon and Gyeonggi) exhibited VNA titers below the protective level (0.06 and 0.29 IU/ml, respectively). The breed and sex of MWDs were not significantly associated with antibody titers for RABV, CDV, or CPV; however, age was significantly associated with CPV antibody titers, while region of residence was associated with CDV antibody titer. Taken together, the data presented here provide important insights necessary for post-vaccination management and control of infectious diseases in MWDs.

Serosurvey of rabies virus, canine distemper virus, parvovirus, and influenza virus in military working dogs in Korea

Rabies virus (RABV), canine distemper virus (CDV), canine parvovirus type-2 (CPV-2), and canine influenza A virus (CIV) are important contagious pathogens in canine populations. To assess post-vaccination immunity against RABV, CDV and CPV-2, and serological evidence of exposure to influenza A virus in military working dogs (MWDs) in Korea, we tested blood samples of 78 MWDs by fluorescent antibody virus neutralization (FAVN) for RABV, and by commercially available enzyme-linked immunosorbent assay (ELISA) for CDV, CPV-2, and CIV. Korean MWDs had high antibody-positive rates against RABV (97.4%, ≥0.5 IU/ml), CDV (94.8%), and CPV (100%). All dogs tested seronegative (0/78; 0%) for influenza A virus. Two 1-year-old dogs stationed in known rabies outbreak areas (Gangwon and Gyeonggi) exhibited VNA titers below the protective level (0.06 and 0.29 IU/ml, respectively). The breed and sex of MWDs were not significantly associated with antibody titers for RABV, CDV, or CPV; however, age was significantly associated with CPV antibody titers, while region of residence was associated with CDV antibody titer. Taken together, the data presented here provide important insights necessary for post-vaccination management and control of infectious diseases in MWDs.

Research on viral agents associated with feline reproductive problems reveals a high association with feline panleukopenia virus

Although reproductive failures (RF) such as abortion, stillbirth and neonatal mortality in cats are still under researched, it is known that many RF are caused by viral agents. This research surveyed the viral agent prevalence in queens with RF. Queens were excluded from the study if their RF was caused by issues other than infection, such as genetic, traumatic, hormonal or nutritional problems, or if they had a history of RF. Blood samples from 26 pregnant females with RF were collected for complete blood counts (BCC), renal/hepatic biochemistry and glycaemic analysis. Ultrasonography was performed to evaluate gestational age and foetal viability. When possible, placentas, humours and foetal tissues were collected. Blood samples were tested by PCR and qPCR for feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), feline alphaherpesvirus 1 (FeHV-1) and carnivore protoparvovirus 1 (CPPV-1). All maternal samples were negative for FeLV, FIV and FeHV-1 and positive for CPPV-1. In addition, foetuses from one queen and three females were positive for CPPV-1 by qPCR and for feline panleukopenia virus (FPV) through DNA sequencing. The BCC and biochemistry results revealed significant neutrophilia, lymphopenia, monocytosis, and liver enzymes. These results provide the first description of an FPV agent causing only RF-related clinical signs in queens.

Epidemiological, clinical and pathological features of canine parvovirus 2c infection in dogs from southern Brazil

ABSTRACT: Canine parvovirus type 2c (CPV-2c) emerged in Europe in the early 2000’s and rapidly spread out worldwide. Clinical and molecular data have demonstrated its circulation in Brazilian dogs, yet detailed descriptions of cases are still lacking. This article describes the epidemiological, clinical and pathological features of 24 cases of CPV-2c-associated disease in dogs submitted to veterinary clinics and laboratory diagnosis in southern Brazil (2014-2016). Most affected dogs presented signs/lesions suggestive of parvovirus enteritis: diarrhea, vomiting, hyperemia and hemorrhage of the serous membrane of the small intestine, diffuse segmental granulation, atrophy of the villi, necrosis and fusion of crypts, squamous metaplasia and epithelial syncytia. A number of cases presented features divergent from the classical presentations, including a wide variation in the color of feces (reddish and/or yellowish, light-brownish, orange-brown and brownish), involvement of adults (4/24) and vaccinated dogs (12/24), extensive involvement of the small intestine (8/20) and the presence of pulmonary edema (7/24) and convulsions (3/24). Feces and intestinal fragments submitted to PCR for the CPV-2 VP2 gene and to virus isolation in cell culture yielded positive results in 100% and 58.3% (14/24) of the cases, respectively. Nucleotide sequencing revealed a high nucleotide identity in VP2 (99.4 to 100%) and a consistent mutation at amino acid 426 (asparagine to glutamic acid), considered a signature of CPV-2c. These results confirm the involvement of CPV-2c in the described cases and demonstrate the importance of CPV-2c infection among Brazilian dogs, calling attention of veterinarians to correctly diagnose the disease, mainly considering the frequent atypical presentations.

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

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.

Comparative efficacy of metoclopramide, ondansetron and maropitant in preventing parvoviral enteritis-induced emesis in dogs

The aim of the study was to evaluate the efficiencies of selected anti‐emetic drugs (metoclopramide, ondansetron and maropitant) in preventing vomiting in the treatment of canine parvoviral enteritis. We designed a randomized, prospective clinical study. PVE quick ELISA test‐positive dogs between 4 and 12 months of age were included in the study. Each of metoclopramide, ondansetron, maropitant and control group had 8 dogs. Metoclopramide and ondansetron were administered as 0.5 mg/kg doses three times a day via intravenous route, and maropitant was administered as 1 mg/kg doses once a day subcutaneously. The number and severity of daily vomitings were recorded. All dogs were treated and monitored for five days; treatments were continued until all animals healed. Metoclopramide, ondansetron and maropitant decreased the severity of vomiting from the first day and the vomiting numbers from the third day in PVE treatment. Obtained results showed that maropitant can be used successfully such as metoclopramide and ondansetron, which are frequently used for PVE treatment. At the same time, it was discovered that metoclopramide, ondansetron and maropitant were equally effective in reducing the frequency and severity of vomiting.

Reliability of clinical diagnosis and laboratory testing techniques currently used for identification of canine parvovirus enteritis in clinical settings

Canine parvovirus type 2 (CPV-2) is the main etiological agent of viral enteritis in dogs. Actually in literature, CPV-2 has been reported with clinical signs that vary from the classical disease, and immunochromatography test and PCR technique have been introduced to veterinary hospitals to confirm CPV-2 diagnosis and other infections. However, the reliability of these techniques has been poorly analyzed. In this study, we evaluated the sensitivity and specificity of veterinary clinical diagnosis, immunochromatography test and PCR technique. Our data indicate that variations in the clinical signs of CPV-2 complicate the gathering of an appropriate diagnosis; and immunochromatography test and PCR technique do not have adequate sensitivity to diagnose positive cases.

Canine parvovirus in Australia: A comparative study of reported rural and urban cases

Canine parvovirus (CPV) is a highly contagious and often fatal disease reported worldwide. Outbreaks occur throughout Australia, and it has been suggested that disproportionally more CPV cases occur in rural locations. However, evidence to support this suggestion-and possible reasons for such a predisposition-has not existed until now. In this study a total of 4870 CPV cases reported from an Australian disease surveillance system between September 2009 and July 2014 were analysed. Australian postcodes were classified as rural or urban (based on human population density) and reported CPV cases were then categorised as rural or urban based on their reported home postcode. Parvovirus cases were predominately young (<12 months), entire, unvaccinated, mixed-breed dogs. More than twice as many of the reported cases were from a rural area (3321 cases) compared to an urban area (1549 cases). The overall case fatality rate was 47.2%; it was higher for those CPV cases reported from urban areas (50.6%) than rural areas (45.5%). A greater proportion of rural cases were younger, entire dogs compared to urban cases. The final multivariable model of CPV cases being reported from a rural area included age (<12 months) and vaccination status (never vaccinated) as significant predictors. Poor socioeconomic status might be a reason for the decision of rural owners not to vaccinate their dogs as readily as urban owners. The excess reporting of rural CPV cases compared to urban cases and the predictive risk factors identified in this study can be used by veterinarians to reduce the incidence of CPV by educating owners about the disease and promoting better vaccination programs in rural areas. This study also supports that the increased risk of CPV in rural areas may necessitate a need for increased vigilance around preventing CPV disease spread, additional care with puppies which are the most susceptible to this disease and tighter vaccination protocols, compared to urban areas.

Genotyping of Canine parvovirus in western Mexico

Canine parvovirus (CPV) is one of the most common infectious agents related to high morbidity rates in dogs. In addition, the virus is associated with severe gastroenteritis, diarrhea, and vomiting, resulting in high death rates, especially in puppies and nonvaccinated dogs. To date, there are 3 variants of the virus (CPV-2a, CPV-2b, and CPV-2c) circulating worldwide. In Mexico, reports describing the viral variants circulating in dog populations are lacking. In response to this deficiency, a total of 41 fecal samples of suspected dogs were collected from October 2013 through April 2014 in the Veterinary Hospital of the University of Guadalajara in western Mexico. From these, 24 samples resulted positive by polymerase chain reaction, and the viral variant was determined by restriction fragment length polymorphism. Five positive diagnosed samples were selected for partial sequencing of the vp2 gene and codon analysis. The results demonstrated that the current dominant viral variant in Mexico is CPV-2c. The current study describes the genotyping of CPV strains, providing valuable evidence of the dominant frequency of this virus in a dog population from western Mexico.

Parvoviral myocarditis in a 5-week-old Dachshund

OBJECTIVE

To describe a case of myocarditis associated with naturally occurring canine parvovirus type 2 (CPV-2).

CASE SUMMARY

A 5-week-old male intact Dachshund dog presented for acute respiratory distress. Limited diagnostic tests prior to the dog experiencing cardiopulmonary arrest included a lateral thoracic radiograph, which indicated cardiomegaly and diffuse unstructured pulmonary infiltrate. Necropsy was performed and results identified a lymphoplasmacytic myocarditis with positive CPV-2 immunohistochemistry within the myocardium.

UNIQUE INFORMATION PROVIDED

This report describes the natural occurrence of CPV-2-associated myocarditis. In addition to highlighting this rare form of canine parvovirus, cardiomyopathy in survivors of the acute viral myocarditis phase is reviewed.

Feline parvovirus infection and associated diseases

Feline panleukopenia, caused by the single-stranded DNA virus feline parvovirus (FPV), is a highly contagious and often lethal disease of cats and other Felidae. FPV, but also canine parvovirus (CPV) can be isolated from both healthy and diseased cats. In Germany, CPV was detected in only approximately 10% of feline samples, but in Southeast Asia, reports estimated that up to approximately 80% of diseased cats were infected with CPV. Infection spreads rapidly, especially in cells with high mitotic activity, such as bone marrow, lymphoid tissue and intestinal crypt cells. Anorexia, vomiting, diarrhoea, neutropenia and lymphopenia are common in clinically affected cases. In utero or neonatal infection can result in cerebellar hypoplasia. Depending on the severity of clinical signs, mortality ranges from 25 to 100%. Effective vaccination and thorough disinfection are of the utmost importance in the prevention of disease transmission in multi-cat households and animal shelters. If clinical signs develop, supportive treatment should be commenced. The efficacy of feline recombinant interferon and FPV antibodies has not been clearly demonstrated. Commercially available vaccines should induce protective immunity when administered according to current guidelines. Recent studies suggest that in some kittens, maternally derived antibodies (MDA) can persist for much longer than has been previously recognised. FPV serum antibody tests are available, but protection status needs to be interpreted with caution in kittens with MDA and a negative titre in adult cats does not necessarily denote lack of protection.

Case series of feline panleukopenia virus in an animal shelter

The aim of this study was to describe a series of confirmed and suspected cases of feline panleukopenia virus (FPV) and in-contact cats in an adoption-guarantee shelter in an FPV-endemic area by reviewing shelter records over a 10-month period (January-October 2010). Cats were divided into three groups: in-contact group - asymptomatic cats that were housed with a FPV fecal antigen (Ag)-positive cat/kitten as part of a litter group (n = 66); FPV-survivors group (FPV-infected survivors) - tested FPV fecal Ag-positive and showed clinical signs of FPV, but survived (n = 27); FPV-non-survivors group (FPV-infected non-survivors) - showed clinical signs of FPV and either tested FPV fecal Ag-positive or were housed with an Ag-positive family member, but did not survive (n = 52). Ages ranged from 3 weeks to 3 years, but most were <6 months old (in-contact group: 79%; FPV-survivors group: 70%; FPV-non-survivors group: 85%). A seasonal peak occurred over summer, but cases occurred year-round. Anorexia, dehydration, fever and diarrhea predominated in the FPV-survivors group, and death was preceded by clinical signs of circulatory shock in the FPV-non-survivors group. Housing litters of kittens with their mother was not associated with improved outcome, perhaps because in this population clinical FPV infection was relatively common in queens arriving at the shelter with susceptible litters.

Booster effect of canine distemper, canine parvovirus infection and infectious canine hepatitis combination vaccine in domesticated adult dogs

Domesticated adult dogs with antibody titer classified as below 'high' to one or more of canine distemper virus (CDV), canine parvovirus type-2 (CPV-2) and canine adenovirus type-1 (CAdV-1) were then given an additional inoculation, and the effectiveness of this booster evaluated 2 months later. Consequently, CDV and CAdV-1 antibody titer experienced a significant increase, but the same effect was not observed in the antibody titer of CPV-2. These findings suggest that with additional inoculation, a booster effect may be expected in increasing antibody titers for CDV and CAdV-1, but it is unlikely to give an increase in CPV-2 antibody titer.

Effects of canine parvovirus strain variations on diagnostic test results and clinical management of enteritis in dogs

OBJECTIVE

To estimate the prevalence of canine parvovirus (CPV) strains among dogs with enteritis admitted to a referral hospital in the southwestern United States during an 11-month period and to compare diagnostic test results, disease severity, and patient outcome among CPV strains.

DESIGN

Prospective observational study.

ANIMALS

72 dogs with histories and clinical signs of parvoviral enteritis.

PROCEDURES

For each dog, a fecal sample or rectal swab specimen was evaluated for CPV antigen via an ELISA. Subsequently, fecal samples (n = 42 dogs) and pharyngeal swab specimens (16) were obtained and tested for CPV antigen via an ELISA and CPV DNA via a PCR assay. For specimens with CPV-positive results via PCR assay, genetic sequencing was performed to identify the CPV strain.

RESULTS

56 dogs tested positive for CPV via ELISA or PCR assay. For 42 fecal samples tested via both ELISA and PCR assay, 27 had positive results via both assays, whereas 6 had positive PCR assay results only. Ten pharyngeal swab specimens yielded positive PCR assay results. Genetic sequencing was performed on 34 fecal or pharyngeal swab specimens that had CPV-positive PCR assay results; 25 (73.5%) were identified as containing CPV type-2c, and 9 (26.5%) were identified as containing CPV type-2b. No association was found between CPV strain and disease severity or clinical outcome.

CONCLUSIONS AND CLINICAL RELEVANCE

CPV type-2b and CPV type-2c posed similar health risks for dogs; therefore, genetic sequencing of CPV does not appear necessary for clinical management of infected patients. The diagnostic tests used could detect CPV type-2c.

Risk factors for death from canine parvoviral-related disease in Australia

Canine parvovirus (CPV) is a highly contagious cause of serious and often fatal disease in dogs worldwide despite the availability of safe and efficacious vaccines. Although a number of studies have focussed on identifying risk factors in disease development, risk factors associated with death from CPV are largely unknown. In this study we analysed a total of 1451 CPV cases reported from an Australian surveillance system - using univariate and multivariate techniques - to determine significant risk factors associated with death and euthanasia. A crude case fatality rate of 42.3% was estimated - higher than has been reported previously. We found that 3.3% of CPV cases had a history of vaccination in the previous 12 months, despite having completed the primary puppy vaccination course. The majority (89.5%) of these cases occurred in dogs <12 months of age, indicating failure of the primary vaccination course to provide protective immunity (most likely due to interference of the vaccine antigen with maternal antibodies but other reasons are discussed). Extending the age at which the final puppy vaccination is administered might be one of several strategies to consider. The final multivariate model showed that in non-litter CPV cases, risk of death was significantly associated with season of diagnosis (summer) and pedigree type (hounds and non-sporting dogs). Euthanasia in non-litter CPV cases was significantly associated with season of diagnosis (summer), state of residence (Northern Territory/South Australia/Tasmania combined), age ( Collapse

Key Words

• canine parvovirus
• risk factors
• vaccination
• epidemiology
• surveillance
• australia

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MESH Headings

• Animals
• Australia/epidemiology
• Dog Diseases/epidemiology
• Dog Diseases/mortality
• Dog Diseases/prevention & control
• Dogs
• Female
• Incidence
• Male
• Parvoviridae Infections/epidemiology
• Parvoviridae Infections/mortality
• Parvoviridae Infections/prevention & control
• Parvoviridae Infections/veterinary
• Parvovirus, Canine
• Risk Factors
• Vaccination/statistics & numerical data
• Vaccination/veterinary

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Grants Collapse

Affiliation(s)

Monika Ling The University of Sydney Faculty of Veterinary Science, 425 Werombi Road, Camden, NSW 2570, Australia
Jacqueline M Norris
Mark Kelman
Michael P Ward

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Collaborators Collapse

In vitro assessment of the feline cell-mediated immune response against feline panleukopeniavirus, calicivirus and felid herpesvirus 1 using 5-bromo-2'-deoxyuridine labeling

In this study an in vitro assay was optimized to detect feline proliferating lymphocytes as an assessment for the cell-mediated immune response. For this purpose, 5-bromo-2′-deoxyuridine (BrdU) labeling was chosen because of its sensitivity and the possibility of further characterization of proliferating cells. The assay was optimized by selecting the best batch and concentration of fetal bovine serum, β-mercaptoethanol concentration, cell density, BrdU incubation time and antigen presenting cell type. Cats were vaccinated with the attenuated Nobivac vaccine Tricat and the peripheral blood lymphocyte proliferation responses were quantified upon in vitro restimulation with inactivated and infectious feline panleukopenia virus (FPV), feline calicivirus (FCV) and felid herpesvirus 1 (FeHV-1). Proliferation signals were detected with inactivated FeHV-1 in the CD8⁺ but not in the CD8⁻ T lymphocyte population, with inactivated FCV and FPV in both CD8⁻ and CD8⁺ T lymphocyte populations. Restimulation with infectious FCV caused significant proliferation in the CD8⁻ T lymphocyte population only while infectious FPV and FeHV-1 seemed to suppress lymphocyte proliferation in both T cell populations. Additional IFN-γ quantification in the culture supernatant revealed a large correlation between the proliferation signals and IFN-γ production, indicating that BrdU labeling is a very reliable technique to assess and characterize feline lymphoproliferative responses to viral antigens in vitro.

Canine parvovirus in Australia: the role of socio-economic factors in disease clusters

To identify clusters of canine parvoviral related disease occurring in Australia during 2010 and investigate the role of socio-economic factors contributing to these clusters, reported cases of canine parvovirus were extracted from an on-line disease surveillance system. Reported residential postcode was used to locate cases, and clusters were identified using a scan statistic. Cases included in clusters were compared to those not included in such clusters with respect to human socioeconomic factors (postcode area relative socioeconomic disadvantage, economic resources, education and occupation) and dog factors (neuter status, breed, age, gender, vaccination status). During 2010, there were 1187 cases of canine parvovirus reported. Nineteen significant (P<0.05) disease clusters were identified, most commonly located in New South Wales. Eleven (58%) clusters occurred between April and July, and the average cluster length was 5.7 days. All clusters occurred in postcodes with a significantly (P<0.05) greater level of relative socioeconomic disadvantage and a lower rank in education and occupation, and it was noted that clustered cases were less likely to have been neutered (P=0.004). No significant difference (P>0.05) was found between cases reported from cluster postcodes and those not within clusters for dog age, gender, breed or vaccination status (although the latter needs to be interpreted with caution, since vaccination was absent in most of the cases). Further research is required to investigate the apparent association between indicators of poor socioeconomic status and clusters of reported canine parvovirus diseases; however these initial findings may be useful for developing geographically- and temporally-targeted prevention and disease control programs.

Canine parvovirus

Since its emergence in 1978, canine parvoviral enteritis has remained a common and important cause of morbidity and mortality in young dogs. The continued incidence of parvoviral enteritis is partly due to the virus's capability to "reinvent" itself and evolve into new, more virulent and resistant subspecies. This article reviews current knowledge about the virus, its epidemiology, clinical manifestation, diagnosis, management, and prevention.