Environmental and host factors associated with seropositivity to New Jersey and Indiana vesicular stomatitis viruses in Costa Rican cattle

A cross-sectional study was conducted in Costa Rican cattle to identify host risk factors and endemic foci for vesicular stomatitis virus New Jersey (VSV NJ) and indiana (VSV IND) serotype The effects of age, gender, breed, residence at specific levels of mean annual rainfall, temperature, relative evapotranspiration potential, and elevation on the risk of seropositivity for VSV NJ and VSV IND were evaluated using a random-effects logistic-regression model which adjusted for overdispersion between herds. A total of 2232 cattle from 348 farms located throughout Costa Rica were examined.

Total seroprevalences of 46% and 21% were found for VSV NJ and VSV IND, respectively. When environmental risk factors were considered, cattle residing in areas between 500 and 1500 m (pre-montane or lower montane moist forest) had a higher risk of seropositivity to VSV BNJ compared with cattle living at lower elevations (odds ratio (OR) ≥ 3.6). In addition, cattle residing at 0–500 m and less than 2 m of annual raifall (tropical dry forest) were also at a higher risk of seropositivity to VSV NJ compared with cattle living at other regions (OR ≥ 10). This evidence suggests that at least two transmission cycles may exist for VSV NJ: one located at a higher elevation and the other found at regions of lower elevation and lower rainfall. These regions may indicate the location of different arthropod vectors of viral reservoirs. Antibody prevalence increased with age, suggesting a relationship between lenght of residence in an endemic area and the likelihood of being seropositive to VSV NJ.

No factors were associated with VSV IND seropositivity. The lack of environmental associations with VSV IND seropositivity suggested that the transmission cycle for this serotype is different than that for SV NJ.     

Herd-level risk factors associated with fecal shedding of Shiga toxin-encoding bacteria on dairy farms in Minnesota,USA

This study aimed to identify herd-level risk factors associated with fecal shedding of Shiga toxin-encoding bacteria (STB) on dairy cattle farms in Minnesota, USA. After adjustment for farm size, risk factors included: use of total mixed ration (TMR) for lactating dairy cows [odds ratio (OR) = 3.0; 95% confidence interval (CI): 1.8 to 5.1], no use of monensin for weaned calves (OR = 4.8, 95% CI: 2.5, 9.3), and no use of decoquinate for preweaned calves (OR = 2.2, 95% CI: 1.4, 3.6). Fecal shedding of STB was more common in small herds (< 100 cows, OR = 3.6, 95% CI: 2.1, 6.2) than in large herds (≥ 100 cows). Herd management factors related to cattle feeding practices were associated with fecal shedding of STB.     

Risk factors for anaplasmosis in dairy cows during the peripartum

Anaplasma marginale is endemic in tropical and subtropical areas around the world. Some studies have suggested that cows during peripartum may present a transient immunosuppression state and development of clinical signs of anaplasmosis. The aim of this study was to investigate the relationship between some risk factors and the seroprevalence of A. marginale in dairy cows during peripartum in Rio de Janeiro, Brazil. The risk factors analyzed in association with the prevalence of antibodies against A. marginale in dairy cows were calving season, reproductive experience, breed standard, tick infestations, stocking density, and milk yield. The antibodies against A. marginale were tested in indirect enzyme-linked immunosorbent assays. A primary screening using a 2 × k contingency table of the exposed variables with the outcomes was performed. All variables for which p?<?0.20 were included in a fixed effects log regression. The risk factors investigated to anaplasmosis were calving (OR 2.61, IC 1.08–7.63), breed standard (OR 3.83, IC 0.08–0.28), reproductive experience (OR 33.7, IC 2.14–5.16), milk yield (OR 3.9, IC 2.24–7.03), Rhipicephalus microplus infestations (OR 10.3, IC 0.05–0.17), and stocking density (OR 22.3, IC 0.05–0.17). Low titers of antibodies against A. marginale during peripartum had been characterized as a period previous to development of clinical anaplasmosis. Thus, studies on anaplasmosis should consider each farm as an epidemiological unit, where environmental and immunological factors may influence the endemic status of the pathogen.     

Seroepidemiology of beef and dairy herds and fetal study of Neospora caninum in Argentina

The purpose of the present work was to study the epidemiology of Neospora caninum in beef and dairy herds in the Humid Pampas of Argentina. The seroprevalence of N. caninum was evaluated in 2414 serum samples of cows from beef and dairy farms. An indirect fluorescent antibody test (IFAT) was used to determine specific antibodies. The sera was screened at a dilution >or=1:200 and >or=1:600 in cows with reproductive disease antecedents and without them, respectively. Cows without history of reproductive diseases from nine beef and fifteen dairy farms were grouped according to the percentage (> or or 相似文献   

Brucellosis and associated risk factors in dairy cattle of eastern Ethiopia

Knowing the status of Bovine brucellosis and associated risk factors is a crucial step in formulating evidence based control scheme. In this study, a total of 967 dairy cows from 307 dairy farms in eastern Ethiopia were serologically tested for Brucella antibodies. The screening was done first using RBPT and positive samples were subsequently subjected to CFT for confirmation. A pre-tested structured questionnaire was used to collect relevant data from 307 dairy cattle owners or attendants to assess their awareness and routine practice. The data were run using univariable logistic regression analysis using STATA version 11.0 for Windows. Accordingly, herd and individual animal seroprevalence were found to be 6.8% (95% CI?=?4.28–10.28) and 1.3% (95% CI?=?0.72–2.29), respectively. The prevalence of sero-reactors among local breeds was observed to be higher compared to cross breed (p?<?0.05). Herd level analysis of the risk factors indicated that in farms with large herd size (>20 animals), the odds ratio (OR)?=?9.13, p?=?0.00, CI?=?3.01–27.69 of having brucellosis was 9.13 times higher than smaller size herds (<20 animals). Intensively managed herds had shown the highest seroprevalence (20.8%) than extensive (6.7%) and semi-intensive (4.2%). Experience of dairy handlers about the disease that cause abortion in late pregnancy was significantly associated (p?<?0.001) with the occurrence of brucellosis in the herds. However, about 91% of the dairy cattle owners/attendants lack awareness about disease(s) that causes abortion in late pregnancy. Similarly risk of having brucellosis in those herds experiencing abortion was 6.3 times higher (OR?=?6.3, p?<?0.001, CI?=?2.50–15.92). This study identified some of the handling practices for aborted and retained fetal materials to be risky. Therefore, the study highlights the need of comprehensive brucellosis surveillance in animal and human and institutions of public education and on farm biosafety measures in shaping proper disease control scheme.

     

Seroepidemiological study of Neospora caninum infection in dogs found in dairy farms and urban areas of Aguascalientes, Mexico

The objective of this study was to describe the seroepidemiology of Neospora caninum infection in dogs in close contact with dairy cattle and dogs from urban areas of Aguascalientes, Mexico, as well as to estimate the possible association between age, gender and size of these groups and seroprevalence. Sera were obtained from samples of 152 dogs in dairy farms and 116 in the urban area, and were subjected to ELISA test. General seroprevalence reached 32%, while the seroprevalence in farm dogs (41%) was significantly higher than in dogs from the urban area (20%) (p<0.05). Regarding age groups, general seroprevalence was greater among dogs between 11 and 15 years of age (67%) remaining equal between males and females (32 and 31%, respectively). Nevertheless, females resident in farms had a higher seroprevalence (42%) than female resident in the urban area. Regarding size, large-sized animals had greater seroprevalence in farms (58%), while in the urban area medium-sized animals were those that had the highest seroprevalence (27%). It was found that dairy farm dogs had a higher risk of infection (OR=2.79; p=0.0004), and that in said group, the age range from <1 to 5 years of age was identified as a risk factor (OR=3.11, p=0.001).     

Risk factors for clinical salmonellosis in Virginia, USA cattle herds

Veterinarians working in several Virginia, USA counties noticed an increase in clinical salmonellosis in cattle herds during 1994. We conducted a case–control study to identify potential risk factors for salmonellosis in cattle herds in this region. The potential impact of exposure to poultry-related factors was of particular interest because of the close proximity of poultry and cattle operations in this part of the state. Information was collected from 23 case farms and 23 control farms matched by herd veterinarian, type of enterprise (beef vs. dairy), and location. Faecal and environmental samples were collected during herd visits for bacteriologic culture.

Salmonella was isolated from 4.7% of 531 faecal, feed, water, and environmental samples collected. Salmonella Typhimurium was the serotype found most frequently in clinical cases in participating herds and from samples collected during study visits. Case herds had a higher percentage of study samples positive for Salmonella. Potential risk factors were screened using methods for pair-matched data and then analyzed in individual conditional logistic-regression models to estimate odds ratios with 95% profile likelihood confidence intervals. Significant factors included: the number of mature cows in the herd (OR=1.01; CI 1.00, 1.03), percent change in the number of mature cows during 1994 (OR=0.68; CI 0.11, 0.96), having calves usually born in a building rather than outdoors (OR=0.17; CI 0.01, 0.98), poultry manure spread on bordering property (OR=4.00; CI 1.00, 26.50), signs of rodents in cattle-housing or feed-storage areas (OR=2.75; CI 0.94, 9.92), and contact of wild geese with cattle or feed (OR=4.5; 1.16, 29.51).     

Factors associated with Neospora caninum serostatus in cattle of 20 specialised Costa Rican dairy herds

Twenty-five specialised Costa Rican dairy farms (located in the Poás area) were used to determine neosporosis seroprevalence and the association of seropositivity with environmental and management factors. The farms involved were selected intentionally and all of them use VAMPP 5.1 (Veterinary Automated Management and Production Control Programme) as management-information system. Holstein–Friesian, Jersey and crosses between them were the most-frequent breeds in these herds. The number of females per farm varied from 41 to 296. Our cross-sectional study had two phases. In the first phase, we determined the presence or absence of seropositivity at herd level. For the second phase, all females in 20 seropositive farms were bled. Serum samples were tested for antibodies to Neospora caninum using an indirect enzyme-linked immunosorbent assay (ELISA). A questionnaire with factors mentioned in the literature was administered to the farmers. Logistic regression (LR with herd as random effect) was used to assess the relationships of the serostatus at the individual level with characteristics of the cows and environmental factors. In the first phase all herds had >20% seropositive females; therefore, all herds were eligible for the second phase. In the second phase, the overall prevalence was 39.7% (1191/3002), and within-herd prevalences were between 25.0 and 70.5%. Age 3–6 years, parity ≤2 of the dam of the cow, Jersey breed and lack of purposive sampling to diagnose abortive infectious disease were associated with positive serostatus; other management and environmental factors did not show significant associations. The lack of association between management and environmental factors with serostatus might be because all farms were exposed to a considerable number of potential factors. That all herds of this study were seropositive for neosporosis and the within-herd prevalence was considerable raises questions about how far the infection is spread in other dairy areas of Costa Rica.     

Prevalence of and risk factors for bovine respiratory syncytial virus (BRSV) infection in non-vaccinated dairy and dual-purpose cattle herds in Ecuador

A cross-sectional study was carried out to determine the seroprevalence and risk factors associated with bovine respiratory syncytial virus (BRSV) infection in non-vaccinated dairy and dual-purpose cattle herds from Ecuador. A total of 2,367 serum samples from 346 herds were collected from June 2008 to February 2009. A questionnaire, which included variables related to cattle, health, management measures, and the environment, was filled out in each herd. Presence of antibodies against BRSV was analyzed using a commercial indirect ELISA test. A logistic regression model was used to determine risk factors associated with BRSV at herd level. The individual seroprevalence against BRSV in non-vaccinated herds in Ecuador was 80.48% [1,905/2,367; 95% confidence interval (CI)?=?78.9-82.1]. The herd prevalence was 91.3% (316/346; 95% CI?=?88.3-94.3), and the intra-herd prevalence ranged between 25% and 100% (mean, 90.47%). The logistic regression model showed that the existence of bordering cattle farms, the dual-purpose farms, and the altitude of the farm (more than 2,338?m above sea level) were risk factors associated with BRSV infection. This is the first study about BRSV prevalence in Ecuador. It shows the wide spread of the BRSV infection in the country. The risk factors found will help to design effective control strategies.     

Estimation of Neospora caninum seroprevalence in dairy cattle from Normandy, France.

An epidemiological study was conducted in Orne (France) on randomly selected dairy herds (42 herds including 1,924 cows and heifers, which were at least 15 months old). The aim was primarily to estimate the seroprevalence of Neospora caninum infection from two blood samples per cow, using an enzyme-linked immunosorbent assay (ELISA) for N. caninum (one positive result indicating infection). The second aim was to test the association between some individual and herd factors and N. caninum seropositivity with a logistic model including a random term effect. The prevalence was estimated at 5.6% (107 seropositive animals). At least 27 of the 42 herds had one seropositive cow or heifer. The intra-herd seroprevalence varied from 1.1 to 8% for 18 positive herds (66.7%). Dogs were present in 36 farms and 104 of the 107 seropositive animals were exposed to them. The factors associated with individual seropositivity were the presence of cats (OR = 0.17; P < 0.001), dogs (OR = 4.35; P = 0.02), rabbits and/or ducks (OR = 2.10; P = 0.04), long calving periods (12 months) (OR = 0.44; P = 0.007), tethered housing (OR = 2.50; P = 0.01), somatic cell counts (200-400 x 10(3) cells/mL) (OR = 0.24; P < 0.001) and pond water supply (OR = 2.43; P = 0.04). In conclusion, the animal and intra-herd seroprevalences were low in dairy cows from Normandy, France.     

Prevalence of anti-Neospora caninum antibodies in cattle and dogs from Western Amazon, Brazil, in association with some possible risk factors

For evaluation of the prevalence of anti-Neospora caninum antibodies and its associated risk factors, serum samples from 2109 cattle (11 beef, 50 dairy and 25 mixed farms) and 174 dogs were examined in the State of Rond?nia, Western Amazon, Brazil. An inquiry was applied in each farm. Sera were examined by the Indirect Fluorescence Antibody Test (IFAT) using cut off dilution of 1:25 for cattle and 1:50 for dogs. Statistical association between the serologic status and several variables were analyzed by linear and logistic regression. The overall herd prevalence of anti-N. caninum antibodies for 86 farms was 72% (61.3-81.2%). Prevalence values were 100, 70 and 64% in beef, dairy and mixed herds, respectively. Herd prevalence in beef herds was significantly different (P<0.05) from dairy and mixed herds. The overall animal prevalence of N. caninum in cattle was 8.8%. Prevalence values by animal were similar in different production types (P>0.05), with values of 9.5, 11.2 and 9.7% for beef, dairy or mixed cattle, respectively. Antibodies were found in 12.6% of the 174 examined dogs. Sixteen (22.8%) out of 70 farms with dogs had at least one dog with anti-N. caninum antibodies. The occurrence of antibodies in cattle was statistically associated with farms having more than 25 cows (OR 9.7, 95% IC 2.9-32.2; P=0.0002). There was no significant association between the presence of the dogs, jungle contact or reproductive variables with the occurrence of antibodies in cattle.     

Herd-level risk factors for Neospora caninum seroprevalence in dairy farms in southern Brazil

A cross-sectional study was used to test the relationship between herd seroprevalence to Neospora caninum and various potential herd-level risk factors in 60 dairy farms located in two distinct regions in southern Brazil. Thirty farms were randomly selected from within each region. A questionnaire was designed to summarize each farm's production system as it might relate to N. caninum transmission. The questionnaire contained 105 closed questions relating to general characteristics of the farms, farm facilities, management, source of food and water, herd health, environment and biosecurity, which included questions relevant to N. caninum transmission, including presence and number of dogs and other animals, purchase of animals and contact with man. Serum samples were collected from 40% of animals in each farm and N. caninum antibodies were detected by immunofluorescent antibody test (IFAT). The association between potential risk factors and the probability of an animal being seropositive was modeled using a generalized estimation equations (GEE) logistic regression model. The model accounted for multilevel correlation of data from multiple animals within herds. The mean (+/-S.D.) number of animals in the 60 herds was 64.5 (+/-45.6), ranging from 20 to 280 females. Blood samples were collected from 1549 animals. The size of the farms varied from 4 to 100 ha (mean 30.1+/-25.9 ha). At least one dog was found in 57 of the 60 dairy farms (95%). The mean number of dogs was 3.1 (+/-1.9), ranging from 0 to 10. All females were raised on pasture. For all cattle sampled, N. caninum seroprevalence was 17.8%. Overall, 93.3% of herds (56/60) had at least one seropositive animal identified. Four variables were significantly associated with N. caninum sero-response in the 57 dairy farms, which were included in the final multivariable model: the number of dogs on the farm, farm area (hectares), feeding pooled sources of colostrum and region. The odds of a cow being seropositive increased 1.13 times for each additional dog present on the farm (P=0.021). Cattle from farms that fed calves colostrum pooled from multiple cows had 1.79 times greater odds for being seropositive for N. caninum (P<0.003). The probability of being seropositive was inverse to the area of the farms, such that cattle had 0.92 times the odds to be seropositive (P=0.014) for each additional 10 ha of farmland. Finally, cattle from farms in region one had 0.71 times the odds to be seropositive than cattle from region two (P=0.035). Results of this study suggest that several risk factors may explain why dairy cattle in Brazil may become exposed to N. caninum. However, further investigation of these factors is necessary because the purpose of this study was to refine and generate hypotheses on N. caninum transmission.     

Prevalence and risk factors associated with bovine viral diarrhea virus infection in dairy herds in Jordan

A cross-sectional study was carried out to determine the seroprevalence and to identify risk factors associated with bovine viral diarrhea virus (BVDV) infection in 62 non-vaccinated dairy herds (671 cows) in Jordan between January and June 2007. Information regarding herd management was recorded through a personal interview with farmers. Antibodies against BVDV were detected using an indirect ELISA test. Chi-square analysis and multivariable logistic regression model were used to identify risk factors for BVDV seropositivity. The true prevalence of antibodies against BVDV in individual cows and cattle herds was 31.6% and 80.7%, respectively. The seroprevalence of BVDV in medium and large size herds was significantly higher than that in smaller herds. There was no significant difference in BVD seroprevalence between different age groups. Random-effects logistic regression model revealed two major factors associated with seropositivity to BVDV; exchange of visits between adjacent farm workers and not isolating newly purchased animals before addition to the herd. The seroprevalence of BVDV in cows located in the northern Jordanian governorates was significantly higher than that in other studied governorates. Results of this study indicated that BVDV is highly prevalent in Jordan and BVDV infection could be controlled by livestock-trade control, and applying strict biosecurity measures in the dairy farms.     

Seroprevalence and risk factors associated to Bovine Herpesvirus 1 (BHV-1) infection in non-vaccinated dairy and dual purpose cattle herds in Ecuador

A cross-sectional study was carried out to determine the seroprevalence and risk factors associated to Bovine Herpesvirus 1 (BHV-1) infection in non-vaccinated dairy and dual purpose cattle herds from Ecuador. A total of 2367 serum samples from 346 herds were collected from June 2008 through February 2009. A questionnaire, which included variables related to cattle, health, management measures and environment was filled out in each herd. A commercial indirect ELISA test was used to determine the seropositivity against BHV-1. Generalized Estimating Equations (GEE) model was used to determine risk factors at individual level, including herd as random effect. The individual seroprevalence to BHV-1 in Ecuador was 43.2% (1023/2367; CI(??%): 41.2-45.2%). The herd prevalence was 82.1%; (284/346; CI(??%): 78.1-86.1%) and the intra-herd prevalence ranged from 12.5 to 100% (mean=64.1%). The GEE model showed that animal age (>4 years) (OR: 1.44; CI(??%): 1.18-1.75), BRSV infection (OR: 1.45; CI(??%): 1.09-1.92), altitude over the sea level (≤ 1800 m) (OR: 2.97; CI(??%): 2.1-4.22) and average slope (> 11%) (OR: 1.45; CI(??%): 1.07-1.95) are risk factors associated with BHV-1 infection, while a good cleaning of the facilities (OR: 0.66; CI(??%): 0.44-0.99) was shown to be a protective factor.     

Seroprevalence and risk factors associated with bovine viral diarrhea virus (BVDV) infection in non-vaccinated dairy and dual purpose cattle herds in Ecuador

A cross-sectional study was carried out to determine the seroprevalence and risk factors associated with Bovine viral diarrhea virus (BVDV) infection in non-vaccinated dairy and dual-purpose cattle herds from Ecuador. A total of 2,367 serum samples from 346 herds were collected from June 2008 through February 2009. A questionnaire, which included variables related to cattle, health, management measures, and the environment, was filled out in each herd. A commercial indirect enzyme-linked immunosorbent assay test was used to determine the seropositivity. A logistic regression model was used to determine risk factors at herd level. The individual seroprevalence for BVDV in non-vaccinated herds in Ecuador was 36.2% (857/2,367; CI_95%, 34.3–38.1%). The herd prevalence was 74% (256/346; CI_95%, 69.4–78.6%) and the intra-herd prevalence ranged between 11.1% and 100% (mean = 51.6%). The logistic regression model showed that the density of cattle farms in the area (more than 70%; OR, 1.94; CI_95%, 1.21–3.2) and the altitude (higher than 2,338 m above sea level; 2.33; CI_95%, 1.4–3.9) are potential risk factors associated with BVDV infection.     

Seroprevalence and risk factors of bovine leptospirosis in the province of Manabí, Ecuador

Leptospirosis is a zoonotic disease with worldwide distribution. The disease affects dairy and beef cattle, causing infertility, abortion, and reduced milk yield. A cross-sectional study was conducted to determine the seroprevalence of leptospirosis in cattle and the associated risk factors in the province of Manabí, Ecuador. Serum samples from 749 animals from 55 cattle herds were analyzed using the microscopic agglutination test (MAT). Animals were considered positive when titers were ≥ 1:100. The association between the potential risk factors and the positive Leptospira result was modeled at both animal and herd level using a generalized linear model with a binomial distribution and logarithmic link. The seroprevalence was 56.21% at the individual level and 98.18% at the herd level. The most prevalent serovars were Pomona (28.57%) and Icterohaemorragiae (22.30%). At the animal level, only the age was associated with leptospirosis seropositivity. Seroprevalence in animals over three years of age was 1.197 (95% confidence intervals (CI), 1.032 – 1.390), higher compared to animals up to three years old. The seroprevalence of Leptospira spp. was higher in farms with no veterinary assistance (PR = 1.209; 95%CI 1.053 – 1.388) and without a vaccination program against Leptospira (PR = 1.399; 95%CI 1.09 - 1.794). In addition, herds from Junín canton had a significantly higher seroprevalence of Leptospira spp (PR = 1.548; 95%CI 1.213 - 1.977) compared to the Bolívar canton, which had the lowest seroprevalence. In conclusion, more than half of the animals were positive to Leptospiraspp, and almost all herds had at least one positive animal. Furthermore, veterinary assistance and vaccination of cattle must be considered as essential aspects of the disease control program.     

Seroprevalence of bovine leukemia virus (BLV) infection in dairy cattle in Isfahan Province, Iran

Bovine leukemia virus (BLV), the causative agent of enzootic bovine leukosis (EBL) is an exogenous C-type oncovirus in the Retroviridae family. It causes significant economic losses associated with the costs of control and eradication programs due to carcass condemnation at slaughter and restrictions of export of cattle and semen to importing countries. The main objective of this research was to determine the seroprevalence of BLV infection in cattle herds in central region of Iran (Isfahan province) using a commercial enzyme-linked immunosorbent assay (ELISA) to detect serum antibodies against BLV. Samples of blood serum were collected from 403 female dairy cattle (Holstein-Friesian) from 21 livestock farms and 303 animals (81.9%) were BLV seropositive. A significant association was found between age as a potential risk factor and BVL seroprevalence with animals ≥ 4 years (86.6%) having a significantly (χ(2) = 35.6, p < 0.001) higher seroprevalence compared to those < 4 years (54.2%). We found no significant statistical association between seroprevalence and pregnancy, lactation status and farming systems as potential risk factors in this study (p > 0.1). It is concluded that BLV infection is a very common problem in the study area. Hence, control measures should be instituted to combat the disease and further studies are required to investigate the impact of this disease on dairy production in the country.     

Seroprevalence and risk factors for leptospirosis in cattle,sheep, and goats at consorted rearing from the State of Piauí, northeastern Brazil

Leptospirosis is an endemic disease in Latin America, caused by pathogenic bacteria of the genus Leptospira. It is considered one of the main causes responsible for the negative economic impact on global livestock by causing reproductive problems. The research aimed to determine the prevalence of leptospirosis in cattle, sheep, and goats at consorted rearing in the micro-region of Teresina, Piauí state, northeastern Brazil, as well as to identify prevalent serovars and risk factors associated with seroprevalence. Serum samples were analyzed in 336 sheep, 292 goats, and 253 cattle using microscopic agglutination test (MAT). Overall, 378 samples were positive to MAT, with seroprevalence of 42.9%. The prevalences in cattle, sheep, and goats were 50.5, 40.5, and 34.6%, respectively. All herds presented at least one seropositive animal; the Hardjo/Wolffi serovar association was the most common in cattle and Icterohaemorrhagiae in goats and sheep. Beef production (OR?=?4.9), cattle herd over 35 animals (OR?=?4.0), feeding on pasture (OR?=?6.4), weir and/or stream as water source (OR?=?2.1), and no veterinary services (OR?=?2.9) were risk factors for cattle infection. For sheep, intensive management system (OR?=?5.3), suspended slatted facilities (OR?=?2.2), more than 20 sheep in reproductive age (OR?=?1.9), and absence of deworming (OR?=?3.5) were the risk factors, while for goats, the identified risk factors were sheep herd over 52 animals (OR?=?1.9) and no veterinary services (OR?=?1.8). We conclude that the infection was spreading in consorted herds in this region. Thus, it would be interesting and important to conduct educative activities to farmers on the economic impacts of this disease and the need of preventive and control strategies mainly focused on sanitary measures and animal handling.     

Risk factors associated with Neospora caninum abortion in Ontario Holstein dairy herds

The objective of this epidemiological study was to identify risk factors for Neospora caninum-related abortions in Ontario Holstein dairy herds. A total of 88 herds, consisting of 5080 cattle, and utilizing Dairy Herd Improvement (DHI) services, were divided into three groups. Case (n = 30) and first control (n = 31) herds were selected from 1998 and 1999 fetal abortion submissions to the Animal Health Laboratory, University of Guelph, that were histopathologically positive or negative, respectively, for N. caninum. A second control group (n = 27) was selected from multiple sources of herds sampled within the previous 4 years that had a low seroprevalence (<7%) to N. caninum. Between May and December 1999, all available cows on all farms, in parity one or greater, were blood sampled. The sera were then analyzed for antibody to N. caninum using a kinetic ELISA. A survey administered at the time of sampling recorded information on housing, animal species present, manure management, reproduction, biosecurity practices, wildlife observations, peri-parturient cow management, herd disease history and nutrition. Production and other herd parameters were obtained from DHI records. Logistic regression indicated that the following parameters were positively associated with a N. caninum abortion in a herd: the N. caninum herd seroprevalence (OR = 1.1), the total number of dogs on a farm (OR = 2.8), the frequency that dogs were observed defecating in mangers (OR = 2.8), the number of horses on a farm (OR = 3.1), the observed annual rate of retained fetal membranes (OR = 1.2) and the observed annual rate of cows returning to estrus after pregnancy confirmation (OR = 1.2). Factors negatively associated were the frequency of stray cats and wild canids observed on a farm (OR = 0.4 and OR = 0.7, respectively) and the housing of heifers on loafing packs (a housing pen divided into feed manger, scrape alley and bedded pack areas, OR = 0.1).