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Seroprevalencia y factores de riesgo de Neospora caninum en pequenas granjas lecheras de la zona central de Chile.

Seroprevalence and risk factors for Neospora caninum in small dairy farms in central Chile

INTRODUCCION

Neospora caninum es un parasito intracelular Apicomplexo, en estrecha relacion con Toxoplasma gondii. Debido a su similitud con T. gondii, la neosporosis ha sido mal diagnosticada durante muchos anos (1). La neosporosis, aunque esta relacionada como causa principal del aborto infeccioso bovino, es principalmente una enfermedad del ganado y de los perros. Se describio por primera vez en perros de Noruega y se aislo por primera vez del ganado bovino (2). Otros informes de neosporosis en Europa, Asia, Oriente Medio, America del Norte y del Sur llaman la atencion sobre esta enfermedad emergente y relevante en el ganado bovino (1). Hasta la fecha, las practicas de manejo que reducen la probabilidad de infeccion son los unicos metodos para combatir la enfermedad, sin existir otros mecanismos de control eficaces para la neosporosis. La variedad y distribucion de los hospederos de N. caninum se encuentra en una amplia gama de especies con distribucion ubicua de reportes de exposicion a N. caninum y anticuerpos parasitarios en cerdos, gatos, zorros, mapaches, camellos, coyotes, roedores, aves y otros animales salvajes. Por otra parte, el aislamiento viable del parasito se ha logrado solamente del perro, de los bovinos, de las ovejas, del bufalo de agua, del bisonte europeo y del ciervo de cola blanca. Los hospederos definitivos son el perro domestico, el dingo australiano y el coyote, siendo bovinos, ovejas, bufalos de agua, caballos, ciervos de cola blanca, entre otros, solo hospederos intermediarios (1).

La principal manifestacion clinica de la neosporosis en el ganado bovino es el aborto. Los casos clinicos pueden mostrar un comportamiento endemico o epidemico, siendo los casos epidemicos definidos como mas del 12.5% de abortos dentro de las 6 a 8 semanas de gestacion (3).

Neospora caninum es un parasito formador de quistes y su desarrollo comprende dos estadios asexuales: taquizoito y bradizoito que ocurren en el hospedero intermedio (por ejemplo, vacas, caballo) y hospederos definitivos (por ejemplo, perro), y una etapa sexual que ocurre solo en los hospederos definitivos. Los taquizoitos se dividen rapidamente dentro de las celulas e infectan multiples tipos celulares incluyendo trofoblastos placentarios, miocitos, hepatocitos, celulas neurales, celulas endoteliales vasculares, celulas renales, macrofagos alveolares, entre otros. Durante la fase enquistada del parasito, los bradizoitos son capaces de replicarse lentamente en tejido del sistema nervioso central (SNC) y los musculos esqueleticos (4). Un hospedero definitivo puede adquirir la infeccion a traves de la ingestion de quistes contenidos en tejidos de animales infectados (5), como la placenta de vacas infectadas naturalmente, lo que es considerado una fuente importante de infeccion para perros. Aunque los ooquistes se eliminan en las heces de los perros y otros hospederos definitivos, hasta la fecha se han identificado ooquistes de N. caninum en pocos perros naturalmente infectados, lo que plantea dudas sobre las frecuencias de desprendimiento y la viabilidad de los ooquistes en los canes.

La deteccion de anticuerpos sericos y de leche se ha utilizado en varios estudios, siendo aparentemente la deteccion en suero mas exacta (1). En America del Sur, se ha reportado una prevalencia de 12.4% en Peru, 14%-97% en Brasil (6) y 14%-80% en Argentina con hallazgos patognomonicos patologicos caracteristicos (7). En Chile, la seropositividad de N. caninum ha sido reportada en ganado lechero en regiones de la zona centro y sur, con tasas que varian entre 15.7% y 30% (8, 9, 10). Recientes datos no publicados indican que entre el 8 y el 22% de los abortos muestran lesiones compatibles con N. caninum en la Region de Los Rios (comunicacion personal). Este estudio tiene como objetivo obtener informacion serologica y de factores de riesgo para neosporosis en granjas lecheras que forman parte de un Servicio de Apoyo Tecnico del Gobierno (SAT) de la region de O'Higgins.

MATERIALES Y METODOS

Tipo de estudio. Estudio de seroprevalencia, incluyendo una encuesta y recoleccion y analisis de muestras.

Poblacion de estudio y area de estudio. La poblacion estudiada fue de vacas lecheras de granjas asociadas al programa de Servicio de Apoyo Tecnico (SAT), en la region de O'Higgins, en la zona central de Chile. Este programa pertenece al Instituto Nacional de Desarrollo Agropecuario (INDAP) y brinda apoyo tecnico a los productores. Hubo 11 granjas asociadas al programa SAT en la Region O'Higgins, en las comunas de Rengo, Las Cabras, Malloa, Quinta de Tilcoco y Peralillo (Figura 1). La poblacion de bovinos fue de 47 animales.

Condiciones climaticas. El area de estudio es un ejemplo de clima mediterraneo con veranos secos y lluvias bajas en invierno.

Recoleccion de datos epidemiologicos. Para evaluar los factores de riesgo potencialmente relevantes, se visito cada granja y se entrevisto a los agricultores. Nueve agricultores aceptaron participar en este estudio. La encuesta se formulo a partir de factores de riesgo de neosporosis previamente descritos (12), incluyendo 28 variables en cuatro areas principales: informacion animal, informacion sobre produccion, factores ambientales y aspectos sanitarios (Tabla 1).

Metodos de laboratorio. Se tomaron tres a cinco ml de sangre de cada vaca (vena coccigea) y se colocaron en tubos al vacio. Las muestras fueron llevadas al laboratorio de la Unidad de Epidemiologia de la Facultad de Ciencias Veterinarias y Pecuarias de la Universidad de Chile, donde se obtuvieron sueros. La identificacion de anticuerpos de N. caninum en sueros de vacas lecheras se llevo a cabo utilizando el kit IDEXX NeosporaX2 Test[R] (IDEXX[R] Laboratories, Inc., Westbrook, Maine, EE.UU.).

Analisis de los datos. Fueron calculadas la seroprevalencia a nivel de granja y dentro de granja. Los datos de la encuesta de factores de riesgo se describieron utilizando metodos de epidemiologia deescriptiva. Posteriormente, se realizo un analisis de regresion logistica para identificar los factores de riesgo de seropositividad a N. caninum (11).

RESULTADOS

En total, 47 bovinos de nueve granjas diferentes fueron muestreados. Dos muestras no pudieron ser analizadas debido a la hemolisis. A nivel de granjas SAT, se pudo determinar una seroprevalencia del 67% (6/9). La seroprevalencia intra granja fue en promedio de 55% (considerando solo las seis granjas positivas). Al considerar el promedio de las nueve granjas, la prevalencia fue de 37% (Tabla 2).

Cuatro variables presentaron una asociacion significativa con la infeccion por N. caninum con p<0.05 siendo estas (Tabla 3): historia del aborto de vacas lecheras (p=0.037, OR=5.09), tipo de alimento proporcionado a los perros (p=0.0429, OR=6), consumo de agua de canales de riego (p=0.034, OR=4.5) y aborto por manejo sanitario de productos (p=0.017, OR = 7.43). Debe mencionarse que algunas variables tuvieron que ser eliminadas del estudio, tales como el proposito de la produccion (todo el ganado es de proposito lechero), la repeticion del celo en las vacas, por una variacion demasiado baja entre las respuestas, el acceso a la sombra (todas las granjas proporcionaban acceso) y estado de condicion sanitaria, con todas las granjas con el mismo manejo, proporcionado por INDAP.

DISCUSION

Un estudio reciente informo un 23% de seroprevalencia de N. caninum en granjas en la region de Biobio (9), previamente se habia identificado una prevalencia intra granja de 16 y 30% (en dos granjas muestreadas) en la Region de la Araucania (8). Este estudio encontro que la seroprevalencia intra granja de N. caninum fue mayor, variando entre 29 a 100%. Las diferencias podrian explicarse por el hecho de que nuestro estudio se realizo en granjas pequenas, en un entorno mucho menos tecnificado comparado con los estudios mencionados anteriormente. Ademas, la Region O'Higgins se encuentra a 300 km al norte de la region de Biobio y a 500 km. al norte de la region de la Araucania, y las condiciones ambientales y climaticas son diferentes, teniendo la Region O'Higgins menos lluvia. No se ha probado que la lluvia sea un factor que afecte la supervivencia o infectividad del parasito en el medio ambiente, pero se ha relacionado con la aparicion de abortos por N. caninum. Las temperaturas medias difieren entre ambas regiones, siendo la Region O'Higgins de aproximadamente dos grados Celsius mas caliente, un factor descrito como significativo, debido a la esporulacion mas rapida de ooquistes en el entorno que rodea al ganado (12).

Los hallazgos patologicos han mostrado evidencia de que el parasito esta presente en Chile y se estan reportando abortos con resultados compatibles de neosporosis (Paredes et al, datos no publicados). Aqui, tres de nueve granjas reportaron abortos en el ultimo ano (33%). De las tres granjas que reportaron abortos, solo dos resultaron positivas para ELISA (+) para anticuerpos de N. caninum. Ninguna de las granjas que reportaron abortos realizaron un diagnostico de la causa de estos. La fuente de agua reportada para los animales fue una mezcla de agua potable, agua de pozo y fuentes de agua abierta como arroyos o canales de riego y fue significativamente correlacionada con el consumo de agua de fuentes abiertas como canales de riego como se informo anteriormente.

En relacion con la propiedad y presencia de perros, la mayoria de las granjas ELISA (+) a Neospora poseian perros (80%) y en 60% reportaron perros ferales en la zona. Se ha reportado la presencia de perro como factor de riesgo para la neosporosis (13). Sin embargo, este estudio no encontro asociacion con la presencia de perro, con la excepcion cuando los perros fueron alimentados con comida casera en lugar de alimentos comerciales para mascotas. Un estudio (8) describio que los perros, en las zonas rurales del sur de Chile, se alimentaban comunmente con visceras bovinas o carne bovina cruda. Finalmente, se identifico la falta de manejo de los abortos y abortos como un factor de riesgo significativo, un factor previamente descrito como relevante para la epidemiologia de la enfermedad (12).

Este estudio, aunque de tamano limitado, permitio a los investigadores examinar una comunidad de agricultores en gran parte marginal, proporcionando una vision sanitaria de sus animales y actividades. Cabe destacar que, aunque el estudio considero solo nueve granjas y 47 animales, estos representan mas del 80% de las granjas y animales pertenecientes a los agricultores que participan en el programa de apoyo SAT en la region y por lo tanto es una muestra relativamente grande del estado sanitario de esta subpoblacion de granjas. Estos resultados destacan la necesidad de mejorar la vigilancia de N. caninum y el desarrollo de medidas preventivas para evitar las perdidas relacionadas con esta enfermedad.

Agradecimientos

Agradecemos al equipo de la unidad de epidemiologia de la Facultad de Ciencias Veterinarias y Pecuarias de la Universidad de Chile, y a PROAGRO Consultores, especialmente a la Dra. Marlene Ortiz. Este estudio fue parcialmente financiado por FONDECYT 11121265.

INTRODUCTION

Neospora caninum is an intracellular Apicomplexan parasite, in close relationship to Toxoplasma gondii. Due to its similarity to T. gondii, neosporosis has been misdiagnosed for many years (1). Neosporosis, although implicated as a major cause of infectious bovine abortion, is primarily a disease of cattle and dogs. It was first described in dogs in Norway and first isolated from cattle (2). Further reports of neosporosis in Europe, Asia, Middle East, North and South America draw attention on this emergent and relevant disease in cattle (1). To date, farm management practices that reduce the chance of infection are the only methods to fight the disease, existing no effective control methods for neosporosis. Host range and distribution of N. caninum is found in a wide range of host species with ubiquitous distribution with reports on animal exposition to N. caninum and parasite antibodies in pigs, cats, foxes, raccoons, camels, coyotes, rodents, birds and other wild animals. On the other hand, viable parasite isolation has been achieved only from dog, cattle, sheep, water buffalo, European bison and white-tailed deer. The definite hosts are domestic dog, Australian dingo, and coyote, being cattle, sheep, water buffalo, horse, white-tailed deer among others only intermediate hosts (1).

The main neosporosis clinical manifestation in cattle is abortion. Clinical cases may show an epidemic or endemic behavior being the epidemic cases defined as more than 12.5% abortions within 6 to 8 weeks of gestation (3).

Neospora caninum is a cyst-forming parasite and its development involves two asexual stages-tachyzoite and bradyzoite that occur in the intermediate host (e.g. cattle, horse) and definitive hosts (e.g. dog), and one sexual stage that takes place only in the definitive hosts. Tachyzoites divide quickly inside the cells and infect multiple cellular types including placental trophoblasts, myocytes, hepatocytes, neural cells, vascular endothelial cells, renal cells, alveolar macrophages, among others. During the encysted phase of the parasite, the bradyzoites, are able to replicate slowly in tissues from the central nervous system (CNS) and skeletal muscles (4). A definitive host may acquire the infection via ingestion of cysts contained in tissues from infected animals (5) such as placenta from naturally infected cows, an important source of infection for dogs. Although oocysts are eliminated in dogs' feces and other definitive hosts, to date N. caninum oocysts have been identified in few naturally infected dogs, raising doubts about the shedding frequencies and oocyst viability in canids.

Serum and milk antibody detection have been used in several studies, being apparently serum detection more accurate (1). In South America, reports indicate prevalence of 12.4% in Peru, 14%-97% in Brazil (6), and 14%-80% in Argentina with characteristic pathognomonic pathological findings (7). In Chile, N. caninum seropositivity has been reported in dairy cattle in central and southern regions, and the rate varies between 15.7% and 30% (8, 9, 10). Recent unpublished reports indicate that between 8 to 22% of abortions show lesions compatible with N. caninum in the Los Rios Region (Personal communication). This study aims to obtain serological information and risk factors for neosporosis on dairy farms that are part of a Government Technical Support Service (SAT) from de O'Higgins region.

MATERIAL AND METHODS

Study type. Seroprevalence study, including a survey and sample collection and analysis. Study population and study area. The study population was milking cows of farms associated to the Technical Support Service (SAT) program, in the O' Higgins region, in central Chile. This program belongs to the Instituto Nacional de Desarrollo Agropecuario (INDAP) and provides technical support to producers. There were 11 farms associated to the SAT program in the O'Higgins Region, in the communes of Rengo, Las Cabras, Malloa, Quinta de Tilcoco and Peralillo (Figure 1). The cattle population was of 47 animals.

Climatic conditions. The study area is an example of Mediterranean climate with dry summers and low winter rainfall.

Epidemiological data collection. To evaluate the potentially relevant risk factors, each farm was visited and farmers where interviewed. Nine farmers accepted to participate in this study. The survey was developed based on previously described risk factors for neosporosis (12), including 28 variables in four main areas: animal information, production information, environmental factors and sanitary aspects (Table 1).

Laboratory methods. Three to five ml of blood from each cow (coccygeal vein) were collected and placed in a vacuum tubes. Samples were taken to the Epidemiology Unit laboratory, at the Faculty of Veterinary Science, University of Chile, where sera was obtained. Identification for antibodies to N. caninum in milking cows' sera was carried out using the IDEXX NeosporaX2 Test[R] (IDEXX[R] Laboratories, Inc., Westbrook, Maine, USA).

Data analysis. Within and among farms seroprevalence was calculated. Risk factor survey data was described using standard descriptive epidemiology methods. Afterwards, a simple logistic regression analysis was carried out, to identify risk factors for seropositivity to N. caninum (11).

RESULTS

Overall 47 cattle from nine different farms were sampled. Two samples could not be analyzed due to hemolysis. The seroprevalence of 67% (6/9) was found at SAT farm level. Within farm seroprevalence results (Table 2) indicate an average of 55% (considering just the six positive farms). When averaging all nine farms, the prevalence was of 37%.

Four variables resulted in a significant association with N. caninum infection with a p<0.05 being these (Table 3): milking cows abortion history (p=0.037, OR=5.09), type of feed provided to dogs (p= 0.0429, OR=6), water consumption from ditches (p=0.034, OR=4.5) and abortion by products sanitary management (p=0.017, OR=7.43). It must be mentioned that some variables had to be removed from the study, such as production purpose (all cattle are dairy animals), repeated heat in cows, with a too low variation among responses, access to shade (all provided access) and sanitary status, with all farms with the same management, provided by INDAP.

DISCUSSION

A recent study reported 23% seroprevalence of N. caninum in farms in the Biobio Region (9), and previously a within farms prevalence of 16 and 30% (in the two sampled farms) was reported in La Araucania region (8). Within farm seroprevalence of N. caninum found in this study was higher, ranging from 29% to 100%. The differences could possibly be explained by the fact that our study was done with small farms, in a much less technified environment comparing with the studies mentioned before. Moreover, the O'Higgins Region is located 300 km. north of Biobio region and 500 km. north of the Araucania region, and the environmental and climatic settings are different, having the O'Higgins Region less rainfall. Rainfall is not a factor proven to affect the survival or infectivity of the parasite in the environment, but it has been linked with the occurrences of N. caninum abortions. Average temperatures differ between both regions, being the O'Higgins region approximately two degrees Celsius warmer, a factor described as significant, due to faster sporulation of oocysts in the environment surrounding cattle (12).

Pathological findings have shown evidence that the parasite is present in Chile and abortions with compatible neosporosis findings are being reported (Paredes et al, unpublished data). Here, three of nine farms reported abortions in the last year (33%). Of those three farms that reported abortions, only two of them resulted positive to ELISA (+) for N. caninum antibodies. None of the farms that reported abortions had the abortions examined or tested for any agent. The reported water source for animals was a mixture of drinking water, well water and open water sources like streams of irrigation channels and was significantly correlated to drinking water from open water sources like irrigation ditches as was previously reported (12).

In relation to dog ownership and presence, most of the Neospora ELISA (+) farms owned dogs (80%) and 60% reported feral dogs in the area. Dog presence has been reported as risk factor for neosporosis (13). Nevertheless, this study did not find association with dog presence, with the exception when dogs were fed with homemade food instead of commercial-pet food. A study (8) described that dogs, in rural areas in Southern Chile, were fed commonly with bovine viscera or raw bovine meat. Finally, the lack of management of abortions and abortions by-products was identified as a significant risk factor, a factor previously described as relevant for the epidemiology of the disease (12).

Most of the Neospora ELISA (+) farms owned dogs (80%) and 60% of the farms reported feral dogs in the area. This finding is consistent with reports of dog presence as a risk factor for neosporosis (12). Nevertheless, this study did not find association with the presence of dogs in farms. A positive relationship was only found when dogs were fed with homemade food instead of commercial-pet food. A study (8) described that dogs, in rural areas in Southern Chile, were fed commonly with bovine viscera or raw bovine meat, behaviour that could be linked to these study results. Finally, the lack of management of abortions and abortions byproducts was identified as a significant risk factor, a factor previously described as relevant for the epidemiology of the disease.

This study, although limited in size, allowed the researchers to screen a largely marginal community of farmers, providing a sanitary insight to their animals and activities. It must be emphasized that although the study considered only nine farms and 47 animals, these are over 80% of the farms and animals belonging to farmers that participate in the SAT support program in the region, and therefore a relatively large sample of the sanitary status of this farms sub population. These results highlight the need of improving N. caninum surveillance, and the development of preventive measures to avoid losses related with this disease.

DOI:dx.doi.org/10.21897/rmvz.926

Received: July 2016; Accepted: November 2016.

Acknowledgments

We thank the team of the epidemiology unit at the School of Veterinary Medicine at the University of Chile, and to PROAGRO Consultores, specially to Dr. Marlene Ortiz. This study was partially funded by FONDECYT 11121265.

REFERENCES

(1.) Dubey JP, Schares G. Neosporosis in animals-The last five years. Veterinary Parasitology 2011; 180(1-2):90-108.

(2.) Dubey JP, Dorough KR, Jenkins MC, Liddell S, Speer CA, Kwok OCH, et al. Canine neosporosis: clinical signs, diagnosis, treatment and isolation of Neospora caninum in mice and cell culture. Int J Parasitol 1998; 28(8):1293-1304.

(3.) Schares G, Peters M, Wurm R, Barwald A, Conraths FJ. The efficiency of vertical transmission of Neospora caninum in dairy cattle analysed by serological techniques. Vet Parasitol 1998; 80(2):87-98.

(4.) Dubey JP, Buxton D, Wouda W. Pathogenesis of bovine neosporosis. J Comp Pathol 2006; 134(4):267-289.

(5.) Cavalcante GT, Monteiro RM, Soares RM, Nishi SM, Alves Neto AF, Esmerini PdO, et al. Shedding of Neospora caninum oocysts by dogs fed different tissues from naturally infected cattle. Vet Parasitol 2011; 179(13):220-223.

(6.) Andreotti R, Barros JC, Pereira AR, Oshiro LM, Cunha RC, Figueiredo Neto LF. Association between seropositivity for Neospora caninum and reproductive performance of beef heifers in the Pantanal of Mato Grosso do Sul, Brazil. Rev Bras Parasitol Vet 2010; 19(2):119-123.

(7.) Calandra PM, Di Matia JM, Cano DB, Odriozola ER, Garcia JA, Spath EJ, et al. Endemic and epidemic bovine neosporosis: description of two events in beef cattle. Rev Argent Microbiol 2014; 46(4):315-319.

(8.) Patitucci AN, Perez MJ, Israel KF, Rozas MA. Prevalence of Neospora caninum in two dairy herds of the IX Region of Chile. Arch Med Vet 2000; 32(2):209-214.

(9.) Gadicke P, Junod T, Lopez-Martin J, Ortega R, Monti G. Enfermedades abortigenicas en lecherias de la Provincia de Nuble: prevalencia y analisis espacial. Arch Med Vet 2016; 48(1):18-26.

(10.) Melendez P, Concha C, Donovan A, Bjorkman C. Evidencia serologica de Neospora caninum en un rebano lechero de la zona central de Chile. Av. en Cs. Vet 1999; 14 (1-2): 13-16.

(11.) Dohoo I, Martin W, Stryhn H. Veterinary Epidemiologic Research. AVC Inc. University of Prince Edward Island Charlottetown 2010.

(12.) Dubey JP, Schares G, Ortega-Mora LM. Epidemiology and control of neosporosis and Neospora caninum. Clin Microbiol Rev 2007; 20(2):323-367.

(13.) VanLeeuwen JA, Haddad JP, Dohoo IR, Keefe GP, Tiwari A, Scott HM. Risk factors associated with Neospora caninum seropositivity in randomly sampled Canadian dairy cows and herds. Prev Vet Med 2010; 93(2-3):129-138.

Luis Herve-Claude [1] Ph.D, Alan Lavado A [2] MV, Dacil Rivera O [2,3] MV, Maria Navarrete-Talloni [4] Ph.D, Christopher Hamilton-West M [2] * Ph.D.

[1] Universidad de Chile, Faculty of Veterinary Sciences, Department of Clinical Sciences, Cattle Surgery and Productive Medicine Unit. Av Santa Rosa 11735, La Pintana, Chile. [2] Universidad de Chile, Faculty of Veterinary Sciences, Department of Preventive Veterinary Medicine, Epidemiology Unit. Av Santa Rosa 11735, La Pintana, Chile. [3] Universidad Andres Bello, Facultad de Ecologia y Recursos Naturales, Escuela de Medicina Veterinaria. Republica 440, Santiago, Chile. [4] Universidad Austral de Chile, Faculty of Veterinary Sciences, Institute of Pathology, Anatomy Pathology Laboratory. Edificio Federico Saelzer tercer piso, Campus Isla Teja. Valdivia, Chile. Correspondence: christopher.hamilton@veterinaria. uchile.cl

Leyenda: Figure 1: Neospora caninum positive and negative dairy farms in the Libertador Bernardo O'Higgins Region in central Chile.
Table 1. Information collected through survey, from
small farms in the Libertador Bernardo
O'Higgins Region, Chile.

General information                  Categories
Farm owner name
Contact phone
Farm address
Commune
Official farm ID number
Latitude
Longitude

Herd information

Number of dairy cattle
Number of milking cows

Individual cow information

DIIO (Official traceability
  ID number)
Cow's age category                Less than 3 years
Breed                             From 3 to 6 years
                                  More than 6 years
                                   Holstein/Jersey
                                     Crossbreed
Abortion history                       Yes/No
Repeated heat                          Yes/No

Herd management/biosecurity

Farm main productive purpose        Agricultural
                                      Livestock
                                        Mixed
                                        Other

Management responsible person

Cattle replacement obtained            Yes/No
  from outside farm
Origin of replacement cattle           Own/Buy
Presence of dogs in the farm           Yes/No
Number of dogs
Acces of other dogs to the             Yes/No
  farm
Owner of other dogs entering            Known
  to the farm
Dogs feed                              Unknown
Dogs feed                             Home made
                                   Commercial feed
Dogs can have access to birth/         Yes/No
  abortion residues
Dogs can have access cow's             Yes/No
  water sources
Dogs can have access cow's             Yes/No
  feed
Other animal species in the
  farm
Number of poultry
Number of Horses
Number of cats
Number of other domestic
  animals
Cattle water source                Drinking water
                                     Water well
                                     Open water
Cattle pen floor                        Muddy
                                         Dry

Herd sanitary conditions

Other diseases present
Brucellosis                            Yes/No
Tuberculosis                           Yes/No
Leucosis                               Yes/No
Deworming                              Yes/No
Placenta/abortion residues
  management

Samples information

Total samples collected
Sample ID

Table 2. ELISA results for Neospora caninum obtained
from cattle in small farms in the Libertador
Bernardo O'Higgins Region.

Farm   No. of animals    No. of sero positive     Within farm
ID         sampled        cows to N. caninum     seroprevalence

A            13                    7                  54%
B             5                    2                  40%
C             2                    0                   0
D             3                    0                   0
E             3                    0                   0
F             4                    3                  75%
G            8a                    2                  29%
H            3a                    2                  100%
I             6                    2                  33%

Table 3. Risk factors identified as significantly
associated to positive serology to Neospora
caninum in dairy cattle in small holders in
the Libertador Bernardo O'Higgins Region.

Variable         Category     Animal    Odds ratio    P value
                               no.       (CI 95%)     (<0.05)

Abortion           Yes          10         5.09        0.037
  history                              (1.10-23.49)
                    No          37         Ref.
Dog feed        Home made       23          6         0.0429
  source                               (1.06-34.00)
Cattle water    Irrigation      16         4.5        0.0334
  source          ditch                (1.13-17.99)
Abortion and                               7.43
  abortion
by products    Non-existent     34                    0.0174
  sanitary                             (1.42-38.78)
  management
                  Buried        13         Ref.
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Title Annotation:ORIGINAL
Author:Herve-Claude, Luis; Lavado, A., Alan; Rivera, Dacil; Navarrete-Talloni, Maria; Hamilton-West, Christ
Publication:Revista MVZ (Medicina Veterinaria y Zootecnia)
Date:Jan 1, 2017
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