Electron microscopic virus diagnosis in dogs, cats, calves, swine and foals in the year 1989

During 1989 fecal and gut samples of 598 dogs, 189 cats, 496 calves, 100 pigs and 66 foals with diarrhoea were investigated for virus by electron microscopy. In samples of dogs and cats Parvovirus was detected in 18.5% and 8.5% of the samples, respectively; Coronavirus was found in 14.9% and in 16.4% of the specimens. In samples of calves Coronavirus dominated with a detection rate of 37.5%, followed by Rotavirus with 10.7% and not clearly identifiable particles resembling Coronavirus (4.2%). In 7.1% of the specimens Rotavirus as well as Coronavirus was found. In 33% of specimens from piglets Coronavirus was detected. 10.6% of the faeces from foals contained Coronavirus-like particles. Between 1987 and 1989 the detection rate of Parvovirus in faeces from dogs and cats decreased from 24.2% to 18.6% and from 17.5% to 8.5%. Coronaviruses in calves, dogs and cats increased from 22.9% to 37.5%, from 5.6% to 14.9% and from 8.2% to 16.4% of the samples investigated.     

Isolation of rotavirus from calves, foals, dogs and cats in New Zealand

The incidence of rotaviruses in calves, foals, dogs and cats in the Dunedin urban and rural areas was investigated using electron microscopy and enzyme-linked immunosorbent assays. Of the 283 faecal specimens examined, 26% were positive for rotavirus. Comparison of the genetic electropherotypes was made by separating the viral dsRNA segments using polyacrylamide gel electrophoresis. It is possible that rotavirus infection is a zoonotic disease.     

The isolation of rotavirus from calves,foals, dogs and cats in New Zealand.

The incidence of rotaviruses in calves, foals, dogs and cats in the Dunedin urban and rural areas was investigated using electron microscopy and enzyme-linked immunosorbent assays. Of the 283 faecal specimens examined, 26% were positive for rotavirus.

Comparison of the genetic electropherotypes was made by separating the viral dsRNA segments using polyacrylamide gel electrophoresis. It is possible that rotavirus infection is a zoonotic disease.     

An electron microscopic study of viruses associated with canine gastroenteritis

An electron microscopic study was carried out on specimens of feces and intestinal contents from cases of canine gastroenteritis submitted to the Diagnostic Laboratory, New York State College of Veterinary Medicine, during 1979-1981. The majority of samples came from New York State and the Northeast with no marked shift in distribution over the three year period. Canine parvovirus was the major virus identified. In August and September 1980 there was an epidemic of canine gastroenteritis, with 247 samples received during this two month period alone, of which 48 percent were positive for canine parvovirus. Almost half of the total number of specimens examined were from dogs less than 6 months of age and well over 50 percent of these were parvovirus positive. In addition to canine parvovirus, three cases of coronavirus, two cases of rota-like virus and one case of astro-like virus were detected. Three dual infections with canine parvovirus and rota or astro-like virus were also confirmed. An unidentified virus-like particle with cubic symmetry was found in two specimens. The adoption of immunoelectron microscopy for the detection of canine parvovirus in March 1980 facilitated identification of this virus and greatly increased the sensitivity of the technique.     

Comparison of direct electron microscopy and enzyme immunoassay for the detection of rotaviruses in calves, lambs, piglets and foals

Direct electron microscopy (EM) and enzyme-immunoassay (rotazyme) results for the detection of rotaviruses in 346 enteric specimens from calves, lambs, piglets and foals were compared. The rotazyme test was at least 3 times more sensitive than direct EM in diagnosing infection. Rotavirus antigen was demonstrated by rotazyme in 22% of 280 scour samples and in 27% of 66 samples from non-scouring animals. There was an association between diarrhoea and higher amounts of rotavirus antigen. This prevalence of rotaviruses detected in animals with diarrhoea highlights the significant involvement of other pathogens identified in the study including Eimeria, Cryptosporidia, Escherichia coli, Campylobacter, and other viruses.     

Infectious diseases of dogs and cats on Isabela Island, Galapagos

BACKGROUND: Vaccination and importation of dogs and cats are prohibited in the Galapagos, resulting in a uniquely isolated population. The purpose of this study was to determine the prevalence of infectious diseases of dogs and cats that impact their health, could spill over to native wildlife, or sentinel diseases of concern to humans. HYPOTHESIS: The isolation of dogs and cats in the Galapagos protects them from diseases common in mainland populations. ANIMALS: Ninety-five dogs and 52 cats presented during a neutering campaign. METHODS: A prospective cross-sectional study was performed. Blood was collected for serological and DNA evaluation of a panel of infectious diseases. RESULTS: Antibodies against parvovirus (100%), parainfluenza virus (100%), adenovirus 1/2 (66-67%), and distemper virus (22%) were present in dogs. Dirofilaria immitis was also common in dogs (34%), with lower prevalences of Wolbachia pipiens (22%), Bartonella sp. (13%), Ehrlichia/Anaplasma spp. (1%), and Mycoplasma haemocanis (1%) observed. Antibodies against panleukopenia virus (67%), Toxoplasma gondii (63%), calicivirus (44%), and herpesvirus 1 (10%) were detected in cats. Feline leukemia virus antigen, feline immunodeficiency virus antibody, or coronavirus antibodies were not detected. Bartonella sp. (44%) infections were common in cats, but only one was infected with M. haemofelis. CONCLUSIONS AND CLINICAL IMPORTANCE: Despite their relative seclusion from the rest of the world, cats and dogs of Isabela were exposed to many pathogens found in mainland South America. Parasite prophylaxis, neutering, and strict enforcement of animal movement restrictions would control a majority of the diseases. In the absence of vaccination, a reservoir of susceptible animals remains vulnerable to new disease introductions.     

Development of nasal, fecal and serum isotype-specific antibodies in calves challenged with bovine coronavirus or rotavirus

Unsuckled specific pathogen free calves were inoculated at 3-4 weeks of age, either intranasally (IN) or orally (O) with bovine coronavirus or O plus IN (O/IN) or O with bovine rotavirus. Shedding of virus in nasal or fecal samples, and virus-infected nasal epithelial cells were detected using immunofluorescent staining (IF), ELISA or immune electron microscopy (IEM). Isotype-specific antibody titers in sera, nasal and fecal samples were determined by ELISA. Calves inoculated with coronavirus shed virus in feces and virus was detected in nasal epithelial cells. Nasal shedding persisted longer in IN-inoculated calves than in O-inoculated calves and longer than fecal shedding in both IN and O-inoculated calves. Diarrhea occurred in all calves, but there were no signs of respiratory disease. Calves inoculated with rotavirus had similar patterns of diarrhea and fecal shedding, but generally of shorter duration than in coronavirus-inoculated calves. No nasal shedding of rotavirus was detected. Peak IgM antibody responses, in most calves, were detected in fecal and nasal speciments at 7-10 days post-exposure (DPE), preceeding peak IgA responses which occurred at 10-14 DPE. The nasal antibody responses occurred in all virus-inoculated calves even in the absence of nasal shedding of virus in rotavirus-inoculated calves. Calves inoculated with coronavirus had higher titers of IgM and IgA antibodies in fecal and nasal samples than rotavirus-inoculated calves. In most inoculated calves, maximal titers of IgM or IgA antibodies correlated with the cessation of fecal or nasal virus shedding. A similar sequence of appearance of IgM and IgA antibodies occurred in serum, but IgA antibodies persisted for a shorter period than in fecal or nasal samples. Serum IgG1 antibody responses generally preceeded IgG2 responses and were predominant in most calves after 14-21 DPE.     

Rotavirus and concurrent infections with other enteropathogens in neonatal diarrheic dairy calves in Spain

Faeces samples from 218, one to 30 days old, diarrheic dairy calves in 65 dairy herds were screened for the presence of rotavirus and concurrent infections with coronavirus, Cryptosporidium, F5+ Escherichia coli and Salmonella spp. Calves were grouped according to their age as follows: 1-7, 8-14, 15-21 and 22-30 days. Rotavirus infection was detected in 46.9%, 45.6%, 33.8% and 48.3% of the calves in the respective age-groups. No significant differences in the detection rate of rotavirus were found among calves on the different age-groups. Rotavirus was the only enteropathogen detected in 39 of the 93 (41.9%) diarrheic calves positive to this agent. Concurrent infections with other enteropathogen(s) were detected in 31.3%, 33.3%, 20.6% and 3.4% of the rotavirus infected calves in the age-groups 1-7, 8-14, 15-21 and 22-30 d, respectively. A significant age-associated decrease in the detection rate of mixed infections (p < 0.01) was found. The detection rates of the other enteropathogens considered in calves with rotavirus infection were 20.4% for coronavirus, 85.2% for Cryptosporidium, 16.7% for F5+ E. coli and 1.8% for Salmonella.     

Detection of rotavirus and coronavirus shedding in two beef cow herds in Idaho

Fecal samples were taken at the time of pregnancy examinations and at parturition from two beef herds. They were also taken from sick calves at the onset of disease, and from 25% of the healthy calves at 15 days of age. All fecal samples were examined by electron microscopy for viruses.

Four cows in herd A were detected excreting coronavirus, one at the time of the pregnancy examinations and three at parturition. The first cow was removed from the herd and the others calved at the end of the season. There were no sick calves.

No cows in herd B were detected excreting virus at the time of pregnancy checks, but fourteen coronavirus and two rotavirus carrier cows were found at parturition. All but two calves sampled had large numbers of virus particles in their feces. Clinical illness was associated with dams shedding virus and with nightly low temperatures.

     

Recent epidemiological status of canine viral enteric infections and Giardia infection in Japan.

Epidemiology of canine enteric infections was studied. Rectal swabs collected from 95 dogs presented at animal hospitals during a period from January to June of 2000 were examined for enteric pathogens, including viruses and Giardia lamblia (G. lamblia). Most frequently detected in both diarrheal and normal feces were canine coronavirus (55.4%) and G. lamblia (48.2%). Canine parvovirus type 2 (CPV-2) was specifically associated with diarrheal cases and CPV-2b was the predominant antigenic type. Although canine rotavirus, canine adenovirus, and canine distemper virus were also detected in a small number of diarrheal cases, no evidence for calicivirus infection was obtained.     

Virological Survey in free-ranging wildcats (Felis silvestris) and feral domestic cats in Portugal

To determine the presence of viral pathogens in natural areas a survey was conducted on an opportunistic sample of fifty eight wild (Felis silvestris silvestris) and feral cats (F. s. catus). The biological materials included serum, lung tissue extract and stool. Feline leukemia virus p27 antigen was detected in 13/50 serum/lung tissue extract samples (26%), canine distemper virus antibodies were detected in 2/26 serum/lung tissue extract samples (7.7%), feline coronavirus RNA was present in 6/29 stool samples (20.7%) and feline parvovirus DNA in 2/29 stool samples (6.9%). Canine distemper virus RNA was not detected. Feline immunodeficiency virus and feline coronavirus antibodies were not detected. Evidence of exposure to feline leukemia virus, canine distemper virus, feline coronavirus and feline parvovirus was found in wild and feral cats raising the importance of performing a comprehensive survey to correctly evaluate the potential threat of infectious diseases to endangered species, namely to the wildcat and to the Iberian lynx, which is meant to be reintroduced after 2012 in Portugal.     

Viruses and virus-like particles in the faeces of dogs with and without diarrhoea

Negative staining electron microscopy was used to identify viruses in 157 normal and 29 diarrhoeal faecal samples collected from 156 dogs admitted to an animal shelter during an 8 month period (March to October) in 1982. Seven distinct viral types were detected: 21-26 nm parvovirus-like particles, 28-31 nm astrovirus-like particles, a previously undescribed 34-35 nm "round" virus particle, coronavirus, coronavirus-like particles ( CVLP ), rotavirus and papova-like virus. Parvovirus-like particles alone were detected in 14 diarrhoeal and 50 normal faeces, astrovirus-like particles in 3 normal faeces, "round" viruses in 4 normal faeces, coronavirus in 2 diarrhoeal and 5 normal faeces, CVLP in one diarrhoeal and one normal faeces, rotavirus in 2 normal faeces, papova-like virus in one normal faeces, both parvovirus-like particles and coronavirus in 2 diarrhoeal and 2 normal faeces, parvovirus-like particles and rotavirus in one normal faeces and parvovirus-like and papova-like virus in one normal faeces. The significance of these findings in canine and human disease is discussed.     

Virus and virus-like particles in the faeces of cats with and without diarrhoea

Negative staining electron microscopy was used to identify viruses in 166 normal and 62 diarrhoeal faecal samples from 208 cats admitted to an animal shelter during a 16-month period (March 1984 to June 1985). On the basis of size and shape 7 distinct viral types were detected: 24 nm parvovirus-like particles, 30 nm astrovirus, 30 nm picornavirus-like particles, reovirus, rotavirus, coronavirus and a 75 nm "togavirus-like" particle. The incidence of these particles in the 208 cats was 11%, 7%, 6%, 0.4%, 5%, 1% and 1% respectively. Virus isolation studies using 40 of the faecal samples succeeded in isolating reovirus 1 in 2 cases. Immune electron microscope studies demonstrated the presence of antibody in a human serum to cat astrovirus, but failed to clarify the identity of the parvovirus-like particles and picornavirus-like particles, other than showing that some of the parvovirus-like particles were not related to feline panleukopenia virus. It was found that parvovirus-like particles, astrovirus, picornavirus-like particles, reovirus and rotavirus could be excreted by cats with normal faeces as well as cats with diarrhoeal faeces. Parvovirus-like particles, astrovirus, picornavirus-like particles and rotavirus could be excreted in high concentration in normal faeces. There was no simple relationship between age and diarrhoea in the population of cats studied. Age was not a critical factor in the excretion of parvovirus-like particles, astrovirus, picornavirus-like particles and rotavirus. The incidence of diarrhoea was not clearly associated with the seasons.     

Certain enteropathogens in calves of Finnish dairy herds with recurrent outbreaks of diarrhea

The occurrence and distribution of certain enteropathogenic organisms and the manifestation of diarrhea, especially in relation to colostral management, were studied in neonatal calves of eight southern Finnish dairy herds with recurrent outbreaks of enteric disturbances. The fecal samples were obtained from the calves and were provided by the farmers. Potentially pathogenic agents were demonstrated in 52 of the 68 calves studied. Cryptosporidium was found in 36 of them while rotavirus was found in 29 and Escherichia coli in 15 of them, either singly or in combination. Salmonella, coronavirus or parvovirus were not detected in any of the calves. Twenty-six of the 36 calves contracted their Cryptosporidium infection and 18 of the 29 calves their rotavirus infection within the first week of life.

Eighteen of the 52 infected calves developed diarrhea of microbial origin within 20 days of age; the most frequent finding was mixed infection with Cryptosporidium and rotavirus. In addition there were six diarrheic calves where no infection could be demonstrated. Only 10 of the 68 calves had neither infections nor diarrhea. There was a highly significant difference between the mean times of the first colostral feeding of the uninfected non-diarrheic and diarrheic calves and a significant difference between the mean times of the first colostral feeding of the subclinically infected and diarrheic calves. The importance of sucking of colostrum at the first feeding was observed. The smallest amount protecting the calves from infections was 0.75 1 given within 1 h of delivery.     

Pathology of calves with diarrhoea in southern Britain

Twenty-one moribund calves with diarrhoea were purchased from 11 farms, their faeces examined for enteropathogens and samples of intestinal tissue removed under anaesthesia. Lesions and presence of enteropathogens on the mucosal surface were scored by histological examination of immunostained paraffin sections. Two or more enteropathogens were detected in 19 calves. Cryptosporidium appeared to be the principal cause of diarrhoea in six calves, rotavirus in four, Salmonella typhimurium in two, bacteria adherent to the surface of the large intestine in two, coronavirus in one and K99+ Escherichia coli in one calf. Diarrhoea in four calves was the consequence of mixed infections in which no one enteropathogen appeared to predominate. In one calf no enteropathogen was detected. Diarrhoea was associated with infections and lesions throughout the small and large intestines. The enteropathogens most frequently associated with lesions in the small intestines were rotavirus, coronavirus and cryptosporidium; in the large intestines they were coronavirus and bacteria apparently adherent to the mucosal surface.     

Microbiology of calf diarrhoea in southern Britain

Faeces samples from calves with diarrhoea in 45 outbreaks were examined for six enteropathogens. Rotavirus and coronavirus were detected by ELISA in 208 (42 per cent) and 69 (14 per cent) of 490 calves respectively; calici-like viruses were detected by electron microscopy in 14 of 132 calves (11 per cent). Cryptosporidium were detected in 106 of 465 (23 per cent), Salmonella species in 58 of 490 (12 per cent) and enterotoxigenic Escherichia coli bearing the K99 adhesin (K99+ E coli) in nine of 310 calves (3 per cent). In the faeces of 20 per cent of calves with diarrhoea more than one enteropathogen was detected; in 31 per cent no enteropathogen was found. Faces samples from 385 healthy calves in the same outbreaks were also examined. There was a significant statistical association of disease with the presence of rotavirus, coronavirus, Cryptosporidium and Salmonella species (P less than 0.001). Healthy calves were not examined for calici-like viruses and the association of K99+ E coli with disease was not analysed because there were too few positive samples. Rotavirus infections were more common in dairy herds and single suckler beef herds whereas Salmonella infections were more often found in calf rearing units. Cryptosporidium were more common in single and multiple suckler beef herds. K99+ E coli were found in one dairy herd and one multiple suckler beef herd both with unhygienic calving accommodation. Variations in coronavirus detection among different farm types were not statistically significant. In this survey rotavirus was the most commonly detected agent in calf diarrhoea and Cryptosporidium were found in approximately one quarter of affected calves. Infection with Salmonella species was widespread, but K99+ E coli infections were less common in the United Kingdom than in other countries.     

Prevalence of rotavirus and coronavirus antigens in the feces of normal cows.

The prevalence of rotavirus and coronavirus shedding by adult cows was investigated using capture enzyme-linked immunosorbent assays. Fecal samples from 121 cows in a single herd were tested for the presence of rotavirus and coronavirus, either free or complexed with immunoglobulin. Free rotavirus was not detected in any samples while rotavirus-immunoglobulin complexes were detected in 53 of 121 (44%) samples tested. In contrast, free coronavirus was detected in six (5%) samples and coronavirus-immunoglobulin complexes were detected in 85 (70%) of the samples tested. Thus it appears that subclinical infection of cows by either of these viruses is common, possibly providing a source for infection of the neonate. These assays may therefore provide important information regarding the epidemiology of enteric virus infections and suggest means of improving management to prevent epidemics of neonatal diarrhea.     

Cryptosporidiosis in neonatal calves: 277 cases (1986-1987)

From January 1986 through December 1987, 277 cases of cryptosporidiosis in calves were diagnosed by the South Dakota State University Diagnostic Laboratory. Cryptosporidium sp was the only pathogen identified in 142 (51.3%) of the calves. Concurrent infections with rotavirus, coronavirus, Escherichia coli, Salmonella sp, bovine viral diarrhea virus, or other pathogens were identified in the remaining 135 calves. After elimination of cases involving autolyzed specimens or calves with chronic diarrhea, records of 11 calves with acute, severe cryptosporidiosis were identified in which Cryptosporidium sp was the only pathogen.     

A comparative study of a new rapid and one-step test for the detection of parvovirus in faeces from dogs, cats and mink

A one-step immunochromatographic test, based on the use of monoclonal antibodies, was developed for the detection of canine parvovirus (CPV) in dog faeces. In addition to canine parvovirus the test can also be used for the diagnosis of infections with viruses causing parvovirus enteritis in cats (feline panleukopenia virus) and mink (mink enteritis virus). Four hundred and forty-three faecal samples were evaluated by comparative testing between this one-step test and three different enzyme-linked immunosorbent assays (ELISA) in Sweden, Denmark and The Netherlands. The result of the evaluation showed an overall relative sensitivity and specificity of 95.8 and 99.7%, respectively. Furthermore, the comparative testing of 83 dog samples in Germany between the one-step test and an immune electron microscopy (IEM) agreed to 85.5%. The sensitivity and specificity were 83.9 and 88.9%, respectively. These results show that the one-step test is a rapid, simple, reproducible and sensitive diagnostic test for the detection of parvovirus in faecal samples of dogs, cats and mink.