RESUMEN
Hydrops foetalis was observed in foetuses from a sheep flock in southern New South Wales over 4 years. Ewes showed marked abdominal distension and most died at parturition, being unable to deliver large affected foetuses. These had birth weights up to 18 kg and exhibited severe generalised oedema of subcutaneous tissues, fluid accumulation in the serous cavities and oedema of the placenta. Microscopically, there was a generalised extramedullary haemopoiesis and massive oedema, consistent with a chronic foetal anaemia. No infectious or environmental factors could be incriminated in the outbreak. The clinical and pathological findings resemble those of the homozygous alpha-thalassaemia in infants associated with haemoglobin Bart's.
Asunto(s)
Edema/veterinaria , Enfermedades Fetales/veterinaria , Complicaciones del Embarazo/veterinaria , Enfermedades de las Ovejas/patología , Animales , Edema/patología , Femenino , Enfermedades Fetales/patología , Embarazo , Complicaciones del Embarazo/patología , OvinosRESUMEN
A population of Ostertagia circumcincta from sheep has been found which, in field and laboratory trials, showed a lack of response to the recommended dose (44 mg/kg) of thiabendazole, suggesting that a degree of resistance exists to this anthelmintic. Preliminary experiments indicated a less than expected response to levamisole. This was not confirmed in a laboratory trial and therefore resistance to this anthelmintic has not been shown conclusively.
Asunto(s)
Resistencia a Medicamentos , Ostertagiasis/veterinaria , Enfermedades de las Ovejas/parasitología , Tiabendazol/uso terapéutico , Trichostrongyloidea/efectos de los fármacos , Tricostrongiloidiasis/veterinaria , Animales , Heces/parasitología , Ostertagiasis/parasitología , Recuento de Huevos de Parásitos , OvinosRESUMEN
Epizootics of congenital neurological defects in calves have been recorded at various intervals in south eastern New South Wales for over 40 years. In 1974 a particularly severe outbreak occurred. Field observations of the clinical entities, their time of appearance, distribution and incidence were recorded in an attempt to determine an epidemiological pattern. The neurological entities observed occupied different time spans in the epizootic, the order of appearance being polioencephalomyelitis, arthrogryposis, hydranencephaly and micrencephaly. The probable period of infection correlated well with the likely presence of Culiciodes brevitarsus in the epizootic area and the distribution and incidence of neurologic cases likewise correlated well with the expected geographical and climatic distribution of C. brevitarsus in this period. The probable association of Akabane virus infection and the outbreak of stillbirths and abortions which preceded the neurologic entities is discussed.