Remarks on the prevalence of some viral respiratory diseases in cattle

Abstract

Serological screening using the ELISA blocking test on 114 serum samples taken from cattle that haven’t been vaccinated had positive results for bovine viral diarrhoea virus (BVD-MD) at a percentage of 43% and for rhino-tracheitis virus (IBR-IPV), the percentage was of 68.42%. The positive results can be explained by the presence of the virus in herds, where the diseases have a subclinical evolution. The serologic investigation using the ELISA blocking test has established the serological prevalence of infections with BVD-MD and IBR-IPV in three farms from Moldavia, the highest prevalence being registered in the case of rhinotracheitis virus (IBR-IPV). The presence of positive reactions, corroborated with the lack of clinical signs in herd can be explained by the presence of latent infections. A wide variety of stimuli such as stress, transport and treatment with corticosteroids may lead to the reactivation of the disease from latency. The obtained results suggest that an extension of serologic investigations in more farms was necessary for finding the animals with subclinical forms.