Signs In Calves Research Articles

Clinical cases of Bluetongue serotype 8 in calves in France in the 2018-2019 winter.

Bluetongue virus serotype 8 (BTV-8) caused an epizootic in Europe in 2006/09. Transplacental transmission of BTV-8 was demonstrated leading to abortions, congenital malformations or nervous clinical signs in newborn calves. BTV-8 re-emerged in France in 2015. Although the re-emergent strain is nearly genetically identical to the one that had circulated in 2006/2009, it has caused very few clinical cases. However, from mid-December 2018 to April 2019, cases of calves with congenital malformations or displaying nervous clinical signs occurred in some departments (French administrative unit) in mainland France. Blood samples from these animals were sent to local laboratories, and the positive ones were confirmed at the French Bluetongue reference laboratory (BT-NRL). Out of 580 samples found positive at the local laboratories, 544 were confirmed as RT-PCR BTV-8 positive. The 36 samples found positive in the local laboratories and negative in the BT-NRL were all at the limit of RT-PCR detection. Hundred eighty-eight of the confirmed samples were also tested for the presence of Schmallenberg virus (SBV) and bovine virus diarrhoea virus (BVDV) infection: 4 were found positive for BVDV and none for SBV. The main clinical signs recorded for 244 calves, for which a reporting form was completed by veterinarians, included nervous clinical signs (81%), amaurosis (72%) and decrease/ no suckling reflex (40%). Hydranencephaly and microphthalmia were reported in 19 calves out of 27 in which a necropsy was practiced after death or euthanasia. These results indicate that the re-emergent strain of BTV-8 can cross the transplacental barrier and cause congenital malformations or nervous clinical signs in calves.

Serum choline and butyrylcholinesterase changes in response to endotoxin in calves receiving intravenous choline administration

Endotoxemia treatment options are still of interest due to high mortality and choline treatment is one of them because of its role in the cholinergic anti-inflammatory pathway. This study investigated serum choline and butyrylcholinesterase (BChE) responses, and their correlations with inflammatory, oxidative stress and tissue damage biomarkers, including paraoxanase-1 (PON1), and clinical signs in calves with endotoxemia and the effect of choline treatment in these responses. Healthy calves (n = 20) were divided equally into 4 groups: Control (0.9% NaCl, iv), Choline (C; 1 mg/kg/iv,once), Lipopolysaccharide (LPS; 2 μg/kg/iv,once) and LPS + C. Clinical and laboratory examinations were performed before and 0.5–48 h (hrs) after treatments.Following LPS administration, serum choline level increased at 0.5-24 h (P < .01), whereas serum BChE and PON1 level decreased at 48 h (P < .01) compared to their baselines. In LPS + C group, the increase in serum choline level was significantly higher (P < .01) than that of C and LPS groups. LPS did not decrease serum BChE levels significantly in calves treated with choline. Serum choline and BChE results correlated negatively with white blood cell count and positively (P < .001) with PON1 levels, oxidative stress index, inflammation and hepato-muscular injury markers.In conclusion serum choline and BChE may have a role in the pathophysiology of endotoxemia in calves. High serum choline concentration is associated with an improvement in response to LPS administration in calves treated with choline, probably by preventing the imbalances between oxidative stress and anti-oxidant capacity, preventing the serum BChE and PON1 decreases, and inhibition/attenuation of acute phase reaction and hepato-muscular injury in calves with endotoxemia.

Isolation of pathogenic Leptospira strains from naturally infected cattle in Uruguay reveals high serovar diversity, and uncovers a relevant risk for human leptospirosis.

Leptospirosis is a neglected zoonosis with worldwide distribution. The causative agents are spirochete bacteria of the Leptospira genus, displaying huge diversity of serovars, the identity of which is critical for effective diagnosis and vaccination purposes. Among many other mammalian species, Leptospira infects cattle, eliciting acute signs in calves, and chronic disease in adult animals often leading to abortions. In South America, and including in Uruguay, beef and dairy export are leading sources of national income. Despite the importance of bovine health, food safety, and bovine-related dissemination of leptospirosis to humans, extremely limited information is available as to the identity of Leptospira species and serovars infecting cattle in Uruguay and the South American subcontinent. Here we report a multicentric 3-year study resulting in the isolation and detailed characterization of 40 strains of Leptospira spp. obtained from infected cattle. Combined serologic and molecular typing identified these isolates as L. interrogans serogroup Pomona serovar Kennewicki (20 strains), L. interrogans serogroup Canicola serovar Canicola (1 strain), L. borgpetersenii serogroup Sejroe serovar Hardjo (10 strains) and L. noguchii (9 strains). The latter showed remarkable phenotypic and genetic variability, belonging to 6 distinct serogroups, including 3 that did not react with a large panel of reference serogrouping antisera. Approximately 20% of cattle sampled in the field were found to be shedding pathogenic Leptospira in their urine, uncovering a threat for public health that is being largely neglected. The two L. interrogans serovars that we isolated from cattle displayed identical genetic signatures to those of human isolates that had previously been obtained from leptospirosis patients. This report of local Leptospira strains shall improve diagnostic tools and the understanding of leptospirosis epidemiology in South America. These strains could also be used as new components within bacterin vaccines to protect against the pathogenic Leptospira strains that are actually circulating, a direct measure to reduce the risk of human leptospirosis.

Effect of Celmanax™ SCP on fecal pathogen shedding, health, and performance of preweaned Holstein dairy calves

Diarrhea in preweaned dairy calves is a significant cause of morbidity and mortality. Optimizing health in this crucial period without antibiotics is of primary interest. Celmanax™ SCP (CSCP) contains derivatives of Saccharomyces cerevisiae cell wall blended with fermentation products. Mannan oligosaccharides (MOS) are yeast cell wall components with binding sites for Gram negative bacteria that lead to pathogen removal. MOS and β-glucans may produce immunomodulatory effects . Dosing with S. cerevisiae has been shown to prevent clinical signs in calves challenged with Salmonella spp. Additionally, S. cerevisiae lowered fecal scores pre- and postweaning (Alugongo et al, 2016]. Our objective was to investigate the effect of CSCP supplementation in Holstein dairy calves, on fecal pathogen shedding, overall health and average daily gain (ADG) during the preweaning period.

Humoral and cellular immune response to Histophilus somni recombinant heat shock protein 60 kDa in farm animals

The aim of this study was to evaluate the effects of immunising farm animals with the Histophi- lus somni recombinant heat shock protein 60kDa ( H. somni rHsp60) in field conditions. Fifty piglets, 10 calves and 30 hens were immunised twice, and the same number of each species was used as the control. The humoral immune response was evaluated using ELISA in piglets (IgG, IgA and IgM) and calves (IgG 1 , IgG 2 and IgM) sera and in hen egg yolks (IgY). Cell-mediated immune responses were evaluated using the skin test. Concentrations of serum haptoglobin in calves and piglets and plasma fibrinogen in calves, daily weight gain in piglets, as well as the inner body temperature and clinical signs in calves were measured to evaluate the clinical effects of vaccina - tion. In animals immunised twice with H. somni rHsp60, a statistically significant increase in IgY antibodies in egg yolk as well as serum IgG 1 and IgG 2 antibodies in calves ( P < 0.05) was found. In piglets, the antibody reaction against H. somni rHsp60 was higher in the experimental than in the control group, but the difference was signifi - cant only for the IgG class ( P < 0.05). A moderate cell-mediated immune response to H. somni rHsp60 measured using the skin test was observed in piglets after 24 h ( P < 0.05), but not in calves and hens. The daily weight gain was significantly higher in the experimental than in the control piglets ( P < 0.05). The fibrinogen and haptoglobin levels in calves, as well as the inner body temperature, indicated a reduced risk of pathology in the experimental group of calves. The preliminary results confirmed the immunogenicity of H. somni rHsp60. A beneficial effect on piglet weight gain was observed. The obtained results warrant further studies of the protective effects of H. somni rHsp60 as an ingredient of subunit vaccines in farm animals.

English

This study was conducted in dairy farms in Khartoum state in order to determine the major causes and risk factors associated with calves&rsquo; mortality. The main results revealed that out of 2,310 animals a highest mortality rate was in Hilat kuku 2.16% (n = 50), followed by Alrudwan and Alseleit 1.73% (n = 24) and 1.04% (n = 40), respectively. Application of analytical statistic using one way analysis of variance (ANOVA) showed a significant difference between the mean of the three sites. The most dominant clinical signs in calves was pneumonia, with prevalence rate of 1.08% (n = 25), 1.08% (n = 25) and 0.079% (n = 18) in Alseleit, Hilat kuku and Alrudwan, respectively. In contrast, diarrhea was not observed in two sites. The difference was statistically significant (X2 = 95.265, P-value = 0.00). Most of the respondents (owner) of the questionnaire survey had a primary level regarding education; Hilat kuku 29.3% (n = 22) and Alseleit 26.7% (n = 20). Further more, most of them had experience of more than 3 years in dairy farms; Hilat kuku 33.3% (n = 25) and 29.3% (n = 22) for the rest of the sites. Education level and experience were found to be statistically significant (X2 = 8.067 and 3.261, P-value = 0.089 and 0.089, respectively). Some risk factors associated with calves&rsquo; mortality rate with regard to management were observed in dairy farms in Khartoum state. For instance, a high significant level (X2 = 17.910, P-value = 0.00) was obtained for feeding of the calves which mainly depended on milk; 33.3% (n = 25) for Alseleit and Hilat kuku and 22.7% (n = 17) for Alrudwan. Moreover, dealing with dead calves was also found to be highly significant (X2 = 11.949, P-value = 0.003) and most of the respondents did nothing regarding this point; Alseleit 25.3% (n = 19) and Hilat kuku 14.7% (n = 11). In contrast, there no significant level (P &gt; 0.05) was recorded for hygiene, quarantine and presence of veterinary services. Key words: Risk factors, calves mortality, dairy farms, Sudan.

Precision and accuracy of clinical illness scores, compared with pulmonary consolidation scores, in Holstein calves with experimentally induced Mycoplasma bovis pneumonia

To determine the precision of a clinical illness score (CIS) system for identification of clinical signs in calves with experimentally induced Mycoplasma bovis pneumonia and to evaluate the accuracy of CISs in relation to pulmonary consolidation scores assigned at necropsy. 178 Holstein bull calves that were 52 to 91 days of age at the time of pneumonia induction. 5 trials involved calves challenged with M bovis and scheduled for euthanasia and necropsy 12 to 24 days afterward. Nine veterinarian observers with various degrees of experience simultaneously assigned CISs to calves within 48 hours before necropsy. The precision of the CIS system among observers was evaluated via the Cohen κ statistic. The accuracy of each observer's CISs relative to 6 cutoffs (≥ 5%, ≥ 10%, ≥ 15%, ≥ 20%, ≥ 25%, and ≥ 30%) of percentage pulmonary consolidation was determined by comparing prenecropsy CISs with the gross pulmonary consolidation scores assigned at necropsy. Estimates for sensitivity and specificity were calculated relative to the 6 pulmonary consolidation cutoffs. A slight level of agreement was evident among observers (κ range, 0.10 to 0.21 for the individual trials) and overall (κ = 0.16; 95% confidence interval, 0.10 to 0.24). Median sensitivity and specificity changed with pulmonary consolidation score cutoff. Median sensitivity for all observers ranged from 81.7% to 98.9%, and median specificity ranged from 80.8% to 94.9% over all cutoff values. Agreement among observers assigning CISs to calves was low; the accuracy of the CIS system in relation to that of pulmonary consolidation scoring varied with the severity of consolidation considered to represent bovine respiratory disease.

Gaur (Bos gaurus) and Banteng (B. javanicus) in the lowland forest mosaic of Xe Pian Protected Area, Lao PDR: abundance, habitat use, and conservation

Gaur (Bos gaurus) and banteng (Bos javanicus) populations throughout South-east Asia have declined severely because of hunting and habitat fragmentation. Important remnant populations persist in Xe Pian national protected area in southern Lao P.D.R., where sign-based surveys were carried out between 1996 and 1998 to determine their distribution, abundance, and patterns of habitat use. Xe Pian is comprised of a largely intact lowland mosaic of semi-evergreen, mixed deciduous, and dry dipterocarp forest types. Gaur used a broader diversity of these habitat types than banteng, attaining moderate densities in homogeneous semi-evergreen forest as well as expanses of deciduous dipterocarp and mixed deciduous forests. Mixed deciduous forest was the least abundant forest type but was commonly used by gaur. Banteng showed a strong affiliation with drier and more open habitats, especially dry dipterocarp forest, despite increased vulnerability to hunting in these areas in the past. Banteng were not found within large expanses of semi-evergreen forest. Their distribution within Xe Pian was therefore more restricted than gaur, though they were relatively more numerous within two isolated corners of the protected area. Signs of calves and juveniles indicated that both species retained breeding populations in Xe Pian. Remaining herds were small – composed of two to five individuals – but bamboo understories in semi-evergreen forest were a food source that attracted larger congregations of gaur in the rainy season. The banteng population in Xe Pian is globally significant for conservation, while that of gaur is nationally significant. The existence of extensive high quality habitat and on-going collaboration of local people lends hope that Xe Pian's wild cattle will increase, given protection from hunting.

Investigations on the influence of serum d-lactate levels on clinical signs in calves with metabolic acidosis

Correlations between the degree of acidosis and clinical signs (changes in posture, behaviour, intensity of suckling reflex) in neonatal diarrhoeic calves have been described in various studies. However, base excess values varied widely in calves exhibiting similar clinical symptoms. The objective of this study was to elucidate whether the clinical picture of acidotic calves with neonatal diarrhoea is influenced more by d-lactate concentration than by degree of acidosis. Eighty calves up to three weeks old that were admitted to the II Medical Animal Clinic with acute diarrhoea and base excess values between −10 and −25 mmol/L were included in the prospective study. Posture, behaviour, suckling and palpebral reflexes, and position of the eyeballs were scored during the initial examination. Base excess and serum d-lactate and urea concentrations were determined in venous blood. In order to quantify the influences of base excess and d-lactate on the clinical parameters, groups of different clinical categories were compared. The results show that variations in behaviour, and in posture can be better explained by elevations of serum d-lactate concentrations than by decreases in base excess. Disturbances of the palpebral reflex appear to be almost completely caused by high levels of d-lactate.

Heterogeneity of the eae genes in attaching/effacing Escherichia coli from cattle: comparison with human strains

Enteropathogenic (EPEC) and enterohaemorrhagic (EHEC) Escherichia coli isolated from cattle were studied by DNA colony hybridization to subtype their intimin-encoding ( eae) gene with probes derived from the variable parts of the eaeα gene of the human EPEC strain E2348/69, the eaeγ gene of the human O157:H7 EHEC strain ATCC43888, and the eaeβ gene of the bovine O26:H- EHEC strain 193, whose eaegene was first cloned and sequenced during this work. The EPEC and EHEC had been isolated from diarrhoeic calves (143 EPEC and 48 EHEC) and from healthy animals at the slaughterhouse (10 EPEC and 34 EHEC). The 191 bovine EPEC and EHEC isolated from diseased calves were positive with the Eaeβ probe (55 and 27% respectively) and with the Eaeγ probe(9 and 73% respectively), whereas 52 EPEC (36%) were negative with the Eaeα, Eaeβ, and Eaeγ probes. The results were different for the 44 bovine EPEC and EHEC isolated from healthy cattle at slaughterhouses: most tested positive with the Eaeγ probe (80 and 82% respectively) and the remaining (20 and 18% respectively) with the Eaeβ probe. Nine O26 human EHEC tested positive with the Eaeβ probe and seven O111 with the Eaeγ probe. The bovine and human EPEC and EHEC belonging to these two serogroups gave identical results: the 18 bovine and human O26 isolates tested positive with the Eaeβ probe, whereas the 13 O111 isolates were positive with the Eaeγ probe. In contrast, the isolates belonging to other serogroups (O5, O15, O18, O20, and O118) gave more variable results. The eaeβ and eaeγ, but not the eaeα, variants were thus distributed amongst bovine EPEC and EHEC. The eaeβ variant seemed to be more frequently associated with the presence of clinical signs in calves, but one third of EPEC from diarrhoeic calves carried an eae gene variant other than the α, β, or γ variants. In addition, the use of these gene probes did not enable differentiation between bovine and human EHEC belonging to the same O serogroup.

Immunization against East Coast Fever in field cattle with low infectivity Theileria parva stabilate—preliminary assessment

Two Theileria parva sporozoite stabilates stored at −196°C, then at −70°C for six weeks (stabilate 1) and more than six months (stabilate 2) were inoculated into four eight-month old male calves, 1 and 2 (stabilate 1), and 3 and 4 (stabilate 2). Calves 1 and 2 developed pyrexia, enlargement of lymph nodes, and the former died of East Coast Fever. Calves 3 and 4 showed slight enlargement of lymph nodes without fever. Lymph node smears from all calves (from day 10 to 20 post-inoculation) showed lymphoblasts, phagocytic macrophages, and schizonts. Piroplasms were detected in erythrocytes in blood smears from calves 1 and 2 but not in calves 3 and 4. Calves 2, 3 and 4 recovered without any treatment while calf 1 died of East Coast Fever on day 20. Serum samples from recovered calves taken on day 30 of the experiment were positive for antischizont antibodies to T. parva at 1:640 dilution, but pre-inoculation serum samples were negative. Stabilate 2 was used to immunize 64 Boran, Friesian, Ayrshire and crosses with Zebu cattle in four herds with 25% reduction of oxytetracycline dose. All the animals except one calf recovered without any severe reactions. The latter died of disease other than ECF after the monitoring period was over (day 24). Day 30 post-inoculation serum samples were positive for T. parva antischizont antibodies. A follow-up of the remaining animals for over one year revealed no further ECF incidences in these herds. This experiment shows the loss of infectivity of the vaccine stored at temperatures higher than −196°C. dependent on the duration. However, despite the lack of clinical signs in calves 3 and 4, there was cellular response and antibody production, and the stabilate for vaccine against East Coast fever can thus be stored prior to use at higher than −196°C and still maintain capability to produce antibodies in field cattle, eliminating the use of oxytetracycline and monitoring. The vaccine will be cheaper and easier to use and the requirement for liquid nitrogen in the field reduced and the scale of application of the vaccine widened.

Clinical signs following experimental lungworm infection and natural bovine respiratory syncytial virus infection in calves.

Similar clinical signs have been reported in calves infected either by Dictyocaulus viviparus or bovine respiratory syncytial virus. Three experiments were carried out to establish the clinical picture and the course of the disease in animals with these infections. The clinical signs of calves infected with lungworm included coughing, nasal discharge, tachypnoea, abdominal breathing and pyrexia, and auscultation of their lungs revealed increased bronchial sounds. Similar signs were also observed after infection with bovine respiratory syncytial virus, but the signs were more acute and resolved more rapidly than in animals infected with lungworm larvae. Calves infected with lungworm had more serious clinical signs after infection with bovine respiratory syncytial virus than calves, which were not infected with lungworm.

Response of the Fowl (Gallus domesticus) to Parenteral Administration of Seven Coccidial Species

Live sporozoites or sporulated viable oocysts of Eimeria tenella caused infection after intravenous, intraperitoneal, intramuscular, subcutaneous, or oral inoculations into susceptible chickens. From 0.5 to 2 hr following intravenous inoculation of oocysts, intact and ruptured oocysts and liberated sporocysts were recovered from the lungs. Similar stages were found in the muscles at the inoculation site following intramuscular inoculation. The oocysts recovered from the muscular or subcutaneous site 7 days after inoculation were dead and could not infect other susceptible birds. The seven species Eimeria tenella, E. necatrix, E. maxima, E. acervulina, E. praecox, E. brunetti, and E. mivati Edgar and Seibold, 1964, are tissue specific and become established in the normal area of the digestive tract usually parasitized by these species following subcutaneous inoculation. In all such parenterally induced infections the infection was mild and showed the same incubation period as after oral inoculation. Inoculation of large numbers of cleaned oocysts in a nontoxic medium was required to produce parenterally induced infections. The oocysts developed by parenterally induced infections were normal and viable. Six trials made using parenteral methods of immunization showed insufficient immunity for field operations. Single, heavy, subcutaneous dosages invariably produced mild infection and some immunity, but protection was stronger following single, nonlethal, oral dosages. Intravenous, intraperitoneal, and intramuscular inoculations of rats with oocysts of Eimeria nieschulzi resulted in normal light infections within the digestive tract of the rat (Landers, 1960). Oocysts were recovered from these parenterally induced infections 7.5 days later. Observations following a second infection by the same route suggested that the first inoculation had produced some immunity. Similarly, intraperitoneal inoculations with sporulated oocysts of E. bovis caused infection and clinical signs in calves 17 to 18 days after injection (Fitzgerald, 1962). The degree of immunity was reported to be directly related to the severity of clinical signs. Intramuscular inoculations of oocysts produced signs neither of clinical coccidiosis nor immunity. Nothing is known about the response of the fowl and the ability of coccidia to cause infection when the latter are introduced parenterally into the host except for a brief report by Davies and Joyner (1962). With bacterial and viral organisms parenteral introduction of living attenuated or unattenuated organisms may produce earlier effective immunity and less clinical symptoms than the same organisms introduced orally. Possibly the same hostparasite relationship holds true following coccidial infections of the fowl. When fed orally, the coccidia pass through the digestive tract and each species is highly specific as to the area in which it develops. This tissue specificity is so distinctive that the area of the digestive tract parasitized is recognized as one of the species characteristics in diagnostic procedures. A study of parenteral inoculation of seven species of chicken coccidia was undertaken to provide information on the biology of these parasites and to determine whether this technique could be used in field immunization against coccidiosis. A preliminary report was presented by Sharma and Reid (1962). Received for publication 19 March 1963. * Taken from a dissertation submitted to the Graduate Faculty of the University of Georgia in partial fulfillment of the requirements for the degree of Doctor of Philosophy (1962). t Present address: Dept. of Zoology, University of Lucknow, Lucknow, U.P., India.