RESUMEN
Foram revisados casos de defeitos congênitos (DCs) diagnosticados em bovinos no Laboratório de Patologia da Universidade Federal de Santa Maria em 1964-2010. Durante o período estudado, foram examinados materiais provenientes da necropsia de 7.132 bovinos e foram encontrados 31 bezerros (0,4 por cento) com DCs, os quais foram classificados em 34 tipos e alocados nos sistemas orgânicos primariamente afetados. Os DCs ocorriam isoladamente (19 [61,3 por cento]) ou afetavam múltiplos sítios anatômicos (15 [28,7 por cento]) com frequência semelhante em ambos os sexos. Como vários terneiros mostraram múltiplos DCs, um total de 53 DCs foi computado. Dos 53 DCs diagnosticados, 15 (28,3 por cento) afetavam o sistema nervoso central (craniósquise [4], abiotrofia cerebelar [2], degeneração esponjosa [2], hidrocefalia [2], meningocele [2], espinha bífida [1], hipoplasia cerebelar [1] e hipomielinogênese [1]); nove (17,0 por cento) afetavam o sistema urogenital (agenesia testicular [1], agenesia vaginal [1], hipoplasia peniana [1], formação de cloaca [1], freemartinismo [1], hamartoma vascular de ovário [1], hipoplasia renal [1], cistos renais [1] e úraco persistente [1]); oito DCs (15,1 por cento) eram primários do sistema musculoesquelético (artrogripose [4], escoliose [1], plagiocefalia, [1] schistosomus reflexus [1] e diprosopia [1]); e outros oito (15,1 por cento) foram alocados no sistema digestivo (palatosquise [3], atresia anal [1], atresia anorretal [1], atresia - anocolônica [1], fístula reto-vaginal [1] e fístula reto-uretral [1]); em cinco ocasiões (9,4 por cento) o DC afetava o sistema cardiovascular (persistência do ducto arterioso [2], persistência do forame oval [2] e defeito do septo ventricular [1]); quatro (7,5 por cento) afetavam o sistema linfático e consistiam de hipoplasia ou aplasia de vasos linfáticos e linfonodos associadas a linfedema. Dois casos (3,4 por cento), de hipotricose foram observados afetando o integumento; um caso (1,9 por cento) de estenose traqueal foi encontrado no sistema respiratório e um caso (1,9 por cento) de bócio envolvia o sistema endócrino. Os resultados indicam que a maioria dos DCs em bovinos na Região Central do Rio Grande do sul é esporádica. No entanto, seu estudo continuado é importante para o estabelecimento de sua etiologia e controle.
Cases of congenital defects (CDs) in cattle diagnosed at the Laboratory of Veterinary Pathology of the Federal University of Santa Maria from 1964 to 2010 were reviewed. During the studied period tissues collected from the necropsy of 7,132 cattle were examined and 31 calves (0.4 percent) with CDs were found. These CDs were classified into 34 different types and ascribed to the body system primarily affected. CDs were solitary (19 [61.3 percent]) or multiple (12 [38.7 percent]) and found with similar frequency in calves of both sexes. As several calves displayed multiple defects, a total of 53 CDs were computed. Out of the 53types of CDs diagnosed 15 (28.3 percent) affected the central nervous system (cranioschisis [4], cerebellar abiotrophy [2], spongy degeneration [2], hydrocephalus [2], meningocele [2], spina bifida [1], cerebellar hypoplasia [1], and hypomyelinogenesis [1]); nine (17.0 percent) affected the urogenital system (testicular agenesis [1], vaginal agenesia [1], penile hypoplasia [1], cloacal formation [1], freemartinism [1], ovarian vascular hamartoma [1], renal hypoplasia [1], renal cysts [1], and persistent urachus [1]); eight CDs (15,1 percent) were primary to the musculoskeletal system (arthrogryposis [4], scoliosis [1], plagiocephaly [1] schistosomus reflexus [1], and diprosopus [1]) and another eight (15,1 percent) were in the digestive system (palatoschisis [3], anal atresia [1], anorectal atresia [1], ano-colonic atresia [1], recto-vaginal fistula [1], and recto-urethral fistula [1]); in five instances (9.4 percent) the CD affected the cardiovascular system (persistent ductus arteriosus [2], persistence of foramen ovale [2], and ventricular septal defect [1]); four (7.5 percent) affected the lymphatic system and consisted of inherited hypoplasia or aplasia of lymphatic vessels and lymph nodes associated with lymphedema. Two cases (3.0 percent), of hypotrichosis were observed affecting the integument; one case (1.9 percent) of tracheal stenosis was found in the respiratory system and one case of goiter (1.9 percent) involved the endocrine system. The results of this survey inidicate that the majority o CDs in cattle in the central Rio Grande do Sul are sporadic; nevertheless their continued study is important for determining the etiology and control.
Asunto(s)
Animales , Anomalías Congénitas/fisiopatología , Anomalías Congénitas/genética , Anomalías Congénitas/mortalidad , Anomalías Congénitas/veterinariaRESUMEN
Latent infection with bovine herpesvirus type-5 (BHV-5) was established in rabbits inoculated with two South American isolates (EVI-88 and 613) by intranasal or conjunctival routes. Nine rabbits (613, 8/27; EVI-88, 1/34) developed neurological disease and died during acute infection and other three (613, n=2; EVI-88, n=1) developed a delayed neurological disease, at days 34, 41 and 56 post-inoculation (p.i.). Between days 56 and 62 p.i., the remaining rabbits were submitted to five daily administrations of dexamethasone (Dx) to reactivate the infection. Twenty-five out of 44 rabbits (56.8%) shed virus in nasal or ocular secretions after Dx treatment. Virus shedding was first detected at day two post-Dx and lasted from one to 11 days. The highest frequencies of virus reactivation were observed in rabbits inoculated conjunctivally (10/15 versus 15/29); and among rabbits infected with isolate 613 (12/16 versus 13/28). Virus reactivation upon Dx treatment was accompanied by neurological disease in nine rabbits (20.4%), resulting in six deaths (13.6%). Virus in moderate titers and mild to moderate non-suppurative inflammatory changes in the brain characterized the neurological infection. Three other rabbits showed severe neurological signs followed by death after 31 to 54 days of Dx treatment. Virus, viral nucleic acids and inflammatory changes were detected in their brains. The late-onset neurological disease, after acute infection or Dx treatment, was probably a consequence of spontaneous virus reactivation. These results demonstrate that BHV-5 does establish a latent infection in rabbits and that clinical recrudescence may occur upon reactivation.
Asunto(s)
Encefalitis Viral/veterinaria , Infecciones por Herpesviridae/veterinaria , Herpesvirus Bovino 5/fisiología , Meningoencefalitis/veterinaria , Enfermedad Aguda , Administración Intranasal , Animales , Bovinos , Enfermedades de los Bovinos/virología , Línea Celular , Corteza Cerebral/virología , Dexametasona/administración & dosificación , Dexametasona/farmacología , Modelos Animales de Enfermedad , Encefalitis Viral/virología , Infecciones por Herpesviridae/virología , Herpesvirus Bovino 5/efectos de los fármacos , Herpesvirus Bovino 5/patogenicidad , Meningoencefalitis/virología , Conejos , Activación Viral/efectos de los fármacos , Latencia del Virus , Replicación Viral , Esparcimiento de VirusRESUMEN
The reproduction effects of bovine viral diarrhea virus type-2 (BVDV-2) infection were investigated in ewes inoculated with a non-cytopathic BVDV-2 isolate at three stages of gestation. Virus inoculation was followed by a transient viremia, accompanied by a transient and mild hyperthermia and nasal discharge in a few animals. Some ewes were sacrificed at different time-points after virus inoculation to study the kinetics of fetal infection. Infectivity and viral antigens were detected in placentomes from day 7 to 36 post-inoculation (pi) and in fetal fluids and tissues between days 10 and 28 pi. Cardiac petechial hemorrhages and hemoperitoneum accompanied by a severe fibrinous ulcerative placentitis were observed in fetuses examined at days 21, 28 and 36 pi. Inoculation of ewes at days 55-60 of gestation resulted in a prolonged virus replication in placentomes and fetal tissues; ewes that were allowed to proceed with pregnancy had 77% of abortions or fetal and perinatal deaths. Seven stillbirths, unviable and viable lambs born to these ewes were virus-positive at birth. Infectious virus was repeatedly isolated from leukocytes of two lambs up to 2 and 6 months of age, indicating they were persistently infected. Ewes inoculated at days 65-70 of gestation had 66.6% of fetal and perinatal losses. Three viable lambs born to these ewes were healthy, BVDV antibody-positive and virus-negative. A transient viral replication in placentomes and in a few fetal tissues, followed by the rise of fetal neutralizing antibodies and virus clearance was the result of inoculating ewes at days 120-125 of gestation. Lambs born to these ewes were healthy, antibody-positive and virus-negative. These results demonstrate that the biology of BVDV-2 infection in pregnant sheep is essentially similar to that of BVDV-1 in pregnant cattle and sheep. These features make this species an attractive animal model for studying the pathogenesis of congenital BVDV-2 infection.
Asunto(s)
Diarrea Mucosa Bovina Viral/patología , Virus de la Diarrea Viral Bovina Tipo 2/crecimiento & desarrollo , Complicaciones Infecciosas del Embarazo/veterinaria , Enfermedades de las Ovejas/virología , Animales , Anticuerpos Antivirales/sangre , Antígenos Virales/análisis , Diarrea Mucosa Bovina Viral/sangre , Diarrea Mucosa Bovina Viral/virología , Brasil , Bovinos , Corteza Cerebral/embriología , Corteza Cerebral/patología , Corteza Cerebral/virología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Femenino , Sangre Fetal/virología , Muerte Fetal/virología , Inmunohistoquímica , Masculino , Placenta/patología , Placenta/virología , Embarazo , Complicaciones Infecciosas del Embarazo/sangre , Complicaciones Infecciosas del Embarazo/virología , Resultado del Embarazo/veterinaria , Distribución Aleatoria , Ovinos , Enfermedades de las Ovejas/patologíaRESUMEN
We demonstrated that sheep are susceptible to acute and latent infection by bovine herpesvirus type-5 (BHV-5). Lambs inoculated intranasally with two South American BHV-5 isolates replicated the virus with titers up to 10(7.1) TCID50/ml for up to 15 days and showed mild signs of rhinitis. Four lambs in contact with the inoculated animals acquired the infection and excreted virus for up to seven days. One lamb developed progressive signs of neurological disease and was euthanized in extremis. Clinical signs consisted of tremors of the face, bruxism, ptyalism, incoordination, lateral flexion of the neck and head, circling, walking backwards, recumbency and paddling. The virus was detected in the anterior and posterior cerebrum, dorso- and ventro-lateral cortex, cerebellum, pons, midbrain and olfactory bulb. Viral nucleic acids were demonstrated in neurons and astrocytes of the anterior and ventro-lateral cortex by in situ hybridization. Histological changes consisting of non-suppurative meningitis, perivascular mononuclear cuffing, focal gliosis, neuronal necrosis and intranuclear inclusions were observed in the anterior cerebrum, ventro-lateral cortex and midbrain. Dexamethasone treatment at Day 50 pi resulted in reactivation of the latent infection and virus shedding in 13/16 (81%) of the lambs. Together with previous reports of BHV-5 antibodies in sheep, these findings show that sheep are fully susceptible to BHV-5 suggesting that infection by BHV-5 in sheep may occur naturally.