The study aimed to examine the capacity of two bovine herpesvirus type 1 (BHV-1) isolates of different subtypes (EVI 123/96, BHV-1.1; SV265/98, BHV-1.2a) to induce respiratory disease in calves. These two isolates are representative of the BHV-1 subtypes prevalent in Brazil. Viral subtypes were confirmed by monoclonal antibody analysis and by restriction enzyme digestion of viral genomes. The viruses were inoculated intranasally into seven 3 months old calves (four with BHV-1.1, three with BHV-1.2a). Three other calves of identical age and condition were kept as uninfected controls. In both groups of infected calves, the clinical signs observed were consistent with typical infectious bovine rhinothracheitis (IBR), including pyrexia, apathy, anorexia, nasal and ocular mucopurulent discharges, erosions on the nasal mucosa, conjunctivitis, lachrymation, redness of nasal mucosa, dyspnoea, coughing, tracheal stridor and enlargement of retropharingeal, submandibular and cervical lymphnodes. No significant differences were observed between the clinical scores attributed to both groups. Virus shedding in nasal and ocular secretions were also similar, apart from a significant difference in nasal virus shedding on day 1 to 3 post-inoculation, which was higher for BHV-1.1 than for BHV-1.2a. Following corticosteroid induced reactivation of the latent infection, recrudescence of clinical signs was also observed, with no significant differences on both groups. It was concluded that both subtypes BHV-1.1 and BHV-1.2a were able to induce clinically undistinguishable respiratory disease in calves, either subsequent to a primary infection or following reactivation.

É descrito o isolamento do vírus Parainfluenza bovino tipo 3 (bPI-3) a partir de secreções nasais coletadas de um bovino com infecção respiratória. A identificação do agente foi realizada através de isolamento em cultivo celular e confirmada por testes de hemaglutinação, inibição da hemaglutinação, hemadsorção e imunofluorescência direta. Este é o primeiro registro do isolamento do vírus no Rio Grande do Sul.

No abstract

ABSTRACT.-Carvalho V.S., Araújo B.R., Vasconcelos T.C., Chiminazzo C., Costa Neto A.O., Ayres M.C.C., Guimarães J. In this paper, Santa Inês crossbred sheep with footrot were evaluated, checking the changes on leukogram and the acute phase proteins. In the ϐirst experiment, 70 females were divided into three groups according to their podal scores: a control group (G1) with score 0, scald group (G2) with score 1 or 2 and a footrot group (G3) with score 3, 4 or 5. During two months, the clinical course and its effect on leukogram were observed at ϐive moments: M1 (day 0), M2 (day 15), M3 (day 30), M4 (day 45) and M5 (day 60). The intensity of the white blood cell count was low magnitude, observing signiϐicant changes (p <0.05) as a mild leukocytosis (G3, M4), attributed to neutrophilia and a slight increase in the total number of monocytes (G3, M2 and M3) despite the extensive damage and tissue necrosis existed during the ϐinal stage of the disease. In the second experiment, 105 animals from seven farms were used with the objective of isolating the causative agent and to evaluate the effect of disease on total plasma protein and acute phase proteins. The animals were also divided into three groups: control, scald and footrot. In all farms, the isolation of Dichelobacter nodosus was regarded. For the different stages of the disease on the proteins studied there was no signiϐicant correlation (p<0.05) but the haptoglobin in scald and footrot groups showed higher average than the control group. Based on these results, we conclude that the acute phase proteins studied were not efϐicient in the characterization of the phases of the disease and the leukocyte response was mild, making it difϐicult to use for this purpose.

A AB BS ST TR RA AC CT TDuring a series of experiments attempting to reproduce clinically apparent bovine herpesvirus type 5 (BoHV-5) infections, a group of calves was inadvertently infected with bovine viral diarrhoea virus (BVDV). Another group of calves was infected with BoHV-5 only. This paper reports the outcome of such infections. Two out of six calves solely infected with BoHV-5 displayed moderate to severe clinical signs. Three out of four calves of the group co-infected with BoHV-5 and BVDV developed severe clinical signs, two of them died. BoHV-5 virus was isolated to higher titres and for a longer period from the group of calves infected with both viruses. These results suggest that BVDV may enhance clinical signs induced by BoHV-5 and may also play a role in extending the period of BoHV-5 shedding.Keywords: BoHV-5, BVDV, co-infection, experimental inoculation RESUMO Durante a realização de experimentos envolvendo inoculações experimentais com herpesvírus bovino tipo 5 (BoHV-5), um grupo de bovinos foi acidentalmente também inoculado com vírus da diarréia viral bovina (BVDV). Os dados obtidos nesta co-infecção foram então comparados a aqueles observados em animais inoculados exclusivamente com