Enteric infections in veal calves: a longitudinal study on four veal calf units

Forty-five calves on four veal calf units were monitored during the first four weeks after their arrival. Faecal samples were collected on alternate days and screened for the presence of rotaviruses, bovine coronavirus, Cryptosporidium oocysts, K99 positive strains of E. coli and Salmonella spp. Rotaviruses and Cryptosporidium were the most commonly detected agents (78% and 60% respectively of the calves). Bovine coronavirus was detected in the faeces of 18% of the calves, whilst K99 positive E. coli was only found in 2 samples from one calf. Salmonella spp. were not isolated from any of the 646 faecal samples examined. Shedding of rotaviruses occurred in a bimodal pattern beginning in the first week of the survey. Cryptosporidium oocysts were detected most frequently in the interval between the two peaks of rotavirus shedding. The presence of rotaviruses or Cryptosporidium oocysts in faeces was not strongly associated with scour, nor were combined infections with these agents or the cases of bovine coronavirus infection. The condition of the calves throughout the survey was generally satisfactory.     

Enteric infections in veal calves: A longitudinal study on four veal calf units

Summary

Forty‐five calves on four veal calf units were monitored during the first four weeks after their arrival. Faecal samples were collected on alternate days and screened for the presence of rotaviruses, bovine coronavirus, Cryptosporidium oocysts, K99 positive strains of E. coli and Salmonella spp. Rotaviruses and Cryptosporidium were the most commonly detected agents (78% and 60% respectively of the calves). Bovine coronavirus was detected in the faeces of 18% of the calves, whilst K99 positive E. coli was only found in 2 samples from one calf. Salmonella spp. were not isolated from any of the 646 faecal samples examined. Shedding of rotaviruses occurred in a bimodal pattern beginning in the first week of the survey. Cryptosporidium oocysts were detected most frequently in the interval between the two peaks of rotavirus shedding. The presence of rotaviruses or Cryptosporidium oocysts in faeces was not strongly associated with scour, nor were combined infections with these agents or the cases of bovine coronavirus infection. The condition of the calves throughout the survey was generally satisfactory.     

The detection of an unidentified type of adenovirus in the stools of calves with weak calf syndrome by use of a commercial kit designed for the detection of human adenoviruses

An outbreak of polyarthritis in newborn calves in a large collective dairy herd was characterized by intra-articular blood-tinged synoviae, blood tainted faeces and massive subcorneal haemorrhages. Faecal samples from eight clinical newborn cases, 10 from unrelated dairy farms and 10 faecal samples from healthy calves were examined by the Rida Quick rotavirus/adenovirus-combi test . A specific adenovirus antigen precipitin-line was seen in the reaction in all the faecal samples from the diseased calves (n = 8), while all the others (n = 20) were negative. In addition, the same positive reaction was noted when one aqueous humor and two synovial samples were tested with this kit. Several other enteropathogens were found sporadically, but no conclusive significance could be attributed to their presence. Bovine viral diarrhoea and infectious bovine rhinothracheitis viruses as well as Chlamydia spp. and Mycoplasma spp. were not involved in this episode.     

Molecular characterization of Giardia intestinalis and Cryptosporidium parvum from calves with diarrhoea in Austria and evaluation of point-of-care tests

To obtain information about the occurrence and genotype distribution of G. intestinalis and C. parvum in Austrian cattle, faecal samples from diarrhoeic calves younger than 180 days of age originating from 70 farms were examined. Of the 177 faecal samples, 27.1% were positive for Giardia cysts (immunofluorescence microscopy) and 55.4% for Cryptosporidium oocysts (phase-contrast microscopy). Positive samples were characterized by nested PCR for Giardia, 83.3% (triosephosphate isomerase; tpi) and 89.6% (β-giardin; bg) were positive, while the Cryptosporidium nested PCR returned 92.5% (60-kDa glycoprotein) positive results. Sequence analysis revealed one assemblage A-positive sample and 30 (bg) respectively 29 (tpi) assemblage E-positive samples for G. intestinalis. For C. parvum four subtypes within the IIa family (IIaA15G2R1, n = 29; IIaA19G2R2, n = 3; IIaA21G2R1, n = 2; IIaA14G1R1, n = 1) could be differentiated. Validation of two immunochromatographic point-of-care tests resulted in a sensitivity of 29.2% and 77.6%; a specificity of 98.4% and 91.1% for the detection of Giardia intestinalis and Cryptosporidium parvum, respectively. Results confirm the widespread occurrence of both protozoa in diarrhoeic calves in Austria.     

Prevalence and molecular characterization of bovine Cryptosporidium isolates in India

A survey based on PCR assay of 18S SSU rRNA gene revealed a 30.2% infection with Cryptosporidium spp., out of 457 faecal samples collected from neonatal bovine calves across three different regions of India. The PCR-RFLP pattern of the gene in all the positive cases established the species as Cryptosporidium parvum. Highest prevalence was recorded in the monsoon months (37.3%) and in the calves showing acute diarrhoea (32.3%). The calves below 15 days of age were mostly affected (45.1%). The infection was more prevalent in the northern parts (35.4%) of the country than in the eastern or southern parts. Results indicated that C. parvum was the only species of Cryptosporidium prevalent in bovine calves in three different geographical regions of India.     

Etiology of respiratory disease in non-vaccinated, non-medicated calves in rearing herds

The aim of this study was to examine the occurrence of bacterial, mycoplasmal and viral pathogens in the lower respiratory tract of calves in all-in all-out calf-rearing units. According to clinical status, non-medicated calves with and without respiratory disease signs were selected of the 40 herds investigated to analyse the micro-organisms present in healthy and diseased calves. Tracheobronchial lavage (TBL) and paired serum samples were analysed for bacteria, mycoplasmas, respiratory syncytial virus (RSV), parainfluenza virus 3 (PIV3), bovine corona virus (BCV) and bovine adenovirus (BAV). Pasteurella multocida was the most common bacterial pathogen. It was isolated from 34% of the TBL samples in 28 herds and was associated with clinical respiratory disease (p < 0.05) when other pathogenic bacteria or mycoplasma were present in the sample. Mannheimia spp. and Histophilus somni were rarely found. Mycoplasma bovis was not detected at all. Ureaplasma diversum was associated with clinical respiratory disease (p < 0.05). TBL samples from healthy or suspect calves were more often negative in bacterial culture than samples from diseased calves (p < 0.05). No viral infections were detected in six herds, while 16-21 herds had RSV, BCV, BAV or PIV3. In the herds that had calves seroconverted to BCV, respiratory shedding of BCV was more frequently observed than faecal shedding. This study showed that the microbial combinations behind BRD were diverse between herds. M. bovis, an emerging pathogen in many countries, was not detected.     

Prevalence of Giardia and Cryptosporidium spp in calves from a region in New Zealand experiencing intensification of dairying

AIM: To investigate the prevalence of Giardia and Cryptosporidium spp in calves born during two spring-calving seasons in a rapidly intensifying dairying region in the South Island; to evaluate potential correlations between the prevalence of the organism and age, characteristics of faeces, and animal-housing practices; and to compare the results with those from established dairying regions in the North Island. METHODS: A longitudinal study was conducted in 2005 and 2006 on 10 dairy farms located in the Otago region, South Island, New Zealand. A total of 1,190 faecal samples were collected from calves 1-7 weeks old. Direct immunofluorescent microscopy was used to screen the faecal samples for Giardia cysts and Cryptosporidium oocysts. The prevalence of Giardia and Cryptosporidium spp detected in calves in Otago was compared with that previously measured in calves from dairying regions in the Waikato and Manawatu, in the North Island . RESULTS: On average, Giardia and Cryptosporidium spp were detected in 31% and 2.6% of all samples, respectively. The prevalence of Giardia spp cysts in faeces was higher in calves >or=3 weeks of age in 2005 (por=2 weeks of age in 2006 (p=0.07) than in younger calves. No age-related pattern was observed for Cryptosporidium spp in either year. No correlations were evident between characteristics of faeces or animal housing practices and the prevalence of either organism, which did not differ between the two dairy farming regions. CONCLUSIONS: Prevalence rates of Giardia and Cryptosporidium spp in calves 1-7 weeks old did not differ between the two geographical regions, nor did the regions' distinct climate conditions appear to influence the prevalence of either pathogen. Considering data from both years together, the presence of Giardia spp cysts in faeces appeared to increase in the first week or two after birth, so that, on average, 30-40% of animals from 3-6 weeks of age were affected. CLINICAL RELEVANCE: This is the first study to report the prevalence of Giardia and Cryptosporidium spp in dairy calves in the South Island of New Zealand.     

Prevalence of Cryptosporidium spp. oocysts in cattle and wildlife in Morogoro region, Tanzania

Prevalences of Cryptosporidium spp. oocysts in cattle (n = 486) on five selected farms in Morogoro municipality and three species of herbivorous wildlife (n = 87) from Mikumi National Park, Morogoro, Tanzania, were determined using the modified Ziehl-Neelsen staining technique. Of 486 bovine faecal samples, 5.3% were positive for Cryptosporidium spp. The prevalence of Cryptosporidium was higher in calves less than 3 months of age compared to weaned calves and adults. Cryptosporidium spp. oocysts were detected in both diarrhoeic and non-diarrhoeic animals, but there was a significantly higher prevalence (P < 0.001) of oocyst shedding in diarrhoeic than in non-diarrhoeic animals. Of the 87 faecal specimens from the wildlife species, 36 were from the African buffaloes (Syncerus caffer), 25 from zebra (Equus zebra) and 26 from the wildebeest (Connochaetes gnou). Cryptosporidium spp. oocysts were detected in eight (22%) buffaloes, seven (28%) zebras and seven (27%) wildebeests. Confirmation of the diagnosis was performed using anti-Cryptosporidium monoclonal antibody specific for Cryptosporidium muris, Cryptosporidium parvum and Cryptosporidium baileyi (Pathasure Cryptosporidium test kit).     

Bacteria of Pathogenic Importance in Faeces from Cadavers of Free-ranging or Corralled Semi-domesticated Reindeer in Northern Norway

There is little information on bacteria that have the potential to cause disease in reindeer husbandry. In this project, faecal samples from 35 free-ranging or corralled reindeer, adults and calves, that died in the winter of 2000 in northern Norway, were examined for the occurrence of Campylobacter spp., Clostridium perfringens, Listeria spp., Salmonella spp. and Yersinia spp. to evaluate the role of these microrganisms in loss and mortality in reindeer husbandry. In addition, 31 of these samples were examined for the occurrence of bacteria producing shigatoxin-1 and 2. C. perfringens was isolated in 20 (57.1%) of the faecal samples. In the free-ranging reindeer, 44% were positive carriers of C. perfringens and 90% of the corralled ones were positive for C. perfringens. In addition, the gene encoding for shigatoxin-1 was detected in one of the samples derived from a corralled reindeer. The other bacteria investigated were not found. Shigatoxin-1-producing bacteria were isolated for the first time from reindeer in Norway. However, no correlation between C. perfringens or shigatoxin-1-producing bacteria and mortality in the reindeer could be established.     

The epidemiology of nematode and fluke infections in cattle in the Red River Delta in Vietnam

Over a period of 13 months, faecal samples were collected monthly from approximately 45 cattle over 3 months of age. Additionally, 74 calves of 1-2 months were sampled to determine the presence of Toxocara vitulorum eggs. Individual egg counts and infective strongyle larvae from pooled faecal samples were examined. Post-mortem worm counts were carried out on six groups of tracer calves (n=12) that had been kept for 4 weeks on pasture in and around the village studied. The following helminths were identified: T. vitulorum, Cooperia punctata, C. pectinata, C. oncophora, Oesophagostomum radiatum, Trichostrongylus axei, T. colubriformis, Haemonchus spp., Fasciola spp. and Paramphistomum spp. In 8% of the samples collected from young calves, individual egg counts for T. vitulorum were found indicative for pathogenic worm burdens. Strongyle egg counts and worm counts indicated that transmission is low without a distinct seasonality. In animals of 3-9 months old, a strongyle egg count peak can be demonstrated which at a higher age steadily and significantly decreased. In faecal cultures Cooperia spp. were most prominent in all age groups throughout the year with the exception of the period September-November when Haemonchus spp. and Oesophagostomum spp. were most prevalent. Fasciola spp. eggs were found in 22% of the collected faecal samples and the egg counts were low indicating that the intensity of Fasciola spp. infection is mild. Based on the present data, regular anthelmintic treatments seem not to be justified, except for a single treatment at the age of 2 weeks against toxocariosis.     

Association of diarrhea in cattle with torovirus infections on farms.

An epidemiologic survey was performed to determine the incidence of torovirus infections in 2 disease entities of cattle: diarrhea of replacement calves up to 2 months old, and winter dysentery of adult cattle. Samples were obtained from 187 diarrheal and 115 healthy calves from 15 farms, as well as 149 diarrheal and 67 healthy cows from 27 farms with or without winter dysentery. Enzyme-linked immunosorbent assays for detection of torovirus, rotavirus, and coronavirus antigen in feces, and of torovirus and coronavirus antibodies in serum were used to monitor infections in these groups. Torovirus was detected in 9 of the 15 farms in the study, and in 6% of calves with diarrhea, which was significantly higher than in healthy calves (2%). Seroconversion to torovirus was found significantly more often after winter dysentery episodes than on farms without a disease history; coronavirus seroconversion was less common.     

The occurrence of Cryptosporidium parvum, Campylobacter and Salmonella in newborn dairy calves in the Manawatu region of New Zealand

AIM: To determine the occurrence of Cryptosporidium parvum oocysts, Campylobacter spp and Salmonella spp in faecal samples taken from newborn dairy calves on 24 dairy farms in the Manawatu region of New Zealand. METHODS: A cross-sectional study was conducted during the 2002 calving season. Faecal samples were collected from 185 newborn calves from a convenience sample of 24 dairy farms. The samples were tested microscopically for the presence of C. parvum oocysts, and bacteriologically for the presence of Campylobacter spp and Salmonella spp. RESULTS: Infections with C. parvum were identified in 33/156 (21.2%) calves from 10 farms. More than 10(6) oocysts/g (OPG) faeces were detected in calves from four farms. Campylobacter spp were isolated from 58/161 (36%) calves from 18 farms; in particular, C. jejuni subsp jejuni was isolated from 11/161 (6.8%) calves from seven farms. Salmonellae were not detected. CONCLUSIONS: Despite the short and concentrated calving pattern and the long interval between calving seasons characterising most dairy farms in New Zealand, C. parvum is widespread among calves. Campylobacter spp, especially C. jejuni, rapidly colonise the intestinal tract of newborn calves. RELEVANCE: This study provided an estimate of the ecological impact of newborn dairy calves with regard to the potentially zoonotic enteric pathogens most frequently isolated from human gastrointestinal infections in New Zealand.     

Detection and analysis of bovine rotavirus strains circulating in Australian calves during 2004 and 2005

Bovine rotavirus (BRV) has been detected in both dairy and beef cattle herds worldwide. Stool samples collected from calves in the Gippsland region of Victoria, Australia were screened to determine the presence of BRV. A total of 100 faecal samples were collected from calves with and without diarrhoea across three farms during 2004 and 2005. Group A BRV was detected in 26% of faecal samples (22 from diarrheic calves and four from asymptomatic calves). Genotyping analysis of rotavirus positive samples indicated that G6P[5] was the most prevalent genotype (38.5%) followed by G6P[5 + 11] (15.4%). G10P[11] and G6 + G10P[5] were each detected at a rate of 7.7%, and G6 + G10P[11] was found in a single sample (3.8%). Seven samples (26.9%) could not be G and/or P typed. Thirty percent of the BRV positive samples were mixed infections, indicating that individual calves were co-infected with more than one strain of rotavirus. The G6P[5] strains exhibited high VP7 identity (>97% amino acid identity) with B-60, a G6 strain identified in Victorian calves during 1988. A G10P[11] isolate was closely related (>97% amino acid identity in VP7 and VP4 proteins) to a Victorian G10P[11] strain (B-11) also identified during 1988. This study demonstrates that BRV is a contributing pathogen to diarrhoeal disease in Victorian calves, with sequence analysis suggesting long-term conservation of the VP7 protein over a 16-year period.     

Experimental infection of calves and sheep with bovine Giardia isolates

9 Giardia-free calves were artificially infected with 1.5-5.1 x 10(6) Giardia cysts originating from Swiss cattle ("bovine isolates"). In 4 of these animals the course of infection was examined. After prepatent periods of 7-8 days all calves excreted high numbers of Giardia cysts for 60-112 days. During patency on 44% of the examination days Giardia cysts and antigen could be detected simultaneously in faecal samples using the flotation method and a sandwich-ELISA, respectively. With the exception of light diarrhoea lasting only for some days at the beginning of patency no other symptoms occurred. Further 5 artificially infected calves were submitted to autopsy. Giardia trophozoites were detected in 4 calves in the jejunum and in 1 animal in the ileum (peroxidase-antiperoxidase method). All animals were simultaneously infected with Campylobacter spp. and/or Rota- and Corona-virus. Electronmicroscopically mucosal attachment sites of Giardia trophozoites had intact microvilli and enterocytes. In various parts of the intestine blunting and flattening of the villi and cellular infiltrations of the mucosa were present. These alterations in calves are generally associated with bacterial and/or viral infections of calves. A Swiss bovine Giardia cyst-isolate was transmitted to 4 Giardia-free conventionally maintained lambs which excreted Giardia cysts after prepatent periods of 10-21 days for 31-61 days.     

Determination of bovine rotavirus G serotype by polymerase chain reaction

A total of 113 diarrheic samples comprising of 68 buffalo calves and 45 cow calves were screened by RNA-PAGE for the detection of presence of rotavirus. RNA-PAGE analysis of these samples revealed 11 (9.73%) was found positive for rotavirus. Out of 68 faecal samples of buffalo calves tested for viral gastroenteritis, 8 (11.76%) were found positive for rotavirus. Similarly, out of 45 faecal samples of cattle calves tested for viral gastroenteritis, 3 (6.66%) was found positive for rotavirus. Rotavirus-positive samples represented long electropherotype. All RNA-PAGE-positive faecal samples for rotavirus subjected to RT-PCR for VP7 gene, ten samples yielded a specific product of 1,013 bp of VP7 gene. All the PCR-positive samples of the present study were subjected to genotyping with primers for G6, G8 and G10 genotype. All positive samples showed G10 genotype. This indicates that G10 may be predominant genotype among bovine calves in Mumbai region in India.