Evidence of point-source exposure to Neospora caninum and protective immunity in a herd of beef cows.
J Am Vet Med Assoc
; 217(6): 881-7, 2000 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-10997162
ABSTRACT
OBJECTIVE:
To determine whether cows with evidence of previous infection with Neospora caninum were less likely to abort or give birth prematurely during an outbreak of neosporosis, compared with herdmates with evidence of primary infection.DESIGN:
Cohort study. ANIMALS 208 pregnant beef cows. PROCEDURES Aborted fetuses and calves born prematurely were examined during an outbreak of neosporosis in a herd of beef cows. Sera were collected from all cows during the outbreak and again 71 days later. Cows were classified into groups on the basis of normal and abnormal reproductive outcomes. Sera were examined, using an avidity ELISA procedure for N caninum, and results were compared between groups and among time points.RESULTS:
Antibody concentrations decreased significantly and IgG avidity values increased significantly over time. During the outbreak, cows with normal reproductive outcomes were significantly more likely to have high IgG avidity values than cows with abnormal reproductive outcomes. CONCLUSIONS AND CLINICAL RELEVANCE The herd had numerous abortions and premature births with evidence of recent point-source exposure to N caninum. Therefore, to reduce risk of transmission of N caninum to cattle, attempts should be made to prevent canine feces from contaminating feed, especially feedstuffs used to prepare mixed rations for cattle. Cows with evidence of previous exposure to N caninum were less likely to abort or give birth prematurely during the outbreak than cows with primary infections with N caninum; this finding suggests development of protective immunity in previously infected cows.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças dos Bovinos
/
Surtos de Doenças
/
Coccidiose
/
Neospora
/
Aborto Animal
Tipo de estudo:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Risk_factors_studies
Limite:
Animals
/
Pregnancy
País/Região como assunto:
America do norte
Idioma:
En
Revista:
J Am Vet Med Assoc
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos