BOOK REVIEWS

Book reviewed in this article:
Guide to the Dissection of Domestic Ruminants . RE Habel
Biology and Medicine of Rabbits and Rodents . JE Harkness and JF Wagner     

Immunogenicity of a soluble antigen againstPasteurella haemolytica-associated pneumonia in calves

Three experiments were performed to evaluate the immunogenic potency of a soluble fraction ofPasteurella haemolytica against pneumonic pasteurellosis in calves. A soluble antigen was extracted by a 2.5% saline solution fromP.haemolytica. Weaned Holstein bull calves, seronegative for infectious bovine rhinotracheitis virus (IBRV) and the pasteurella antigen, were vaccinated either by repeated subcutaneous (SC) vaccination, or by exposure 3 times to the aerosol ofP.haemolytica antigen. Challenge exposure to aerosol ofP.haemolytica was preceded by infection with IBRV, or in experiments 2 and 3, the virus exposures were combined with a stress treatment. The lung lesions were examined at necropsy 3 to 8 days post infection. In the first experiment, all the vaccinated calves produced specific antibody response to the pasteurella antigen, and none of the calves including controls showed significant lesions in the lung. In the second experiment 2 aerogenically vaccinated calves had no lesions. One of the two SC-vaccinated calves had mild consolidated lesions. Two control calves, one of which died 3 days following the challenge, developed severe fibrinous pneumonia with consolidation of 50% or more of the lung surfaces.P.haemolytica was isolated only from the 2 control animals. In the third experiment, 2 of the 3 control calves developed moderate to severe consolidation, butP.haemolytica was isolated only from one of them. Two of the three aerosol-vaccinated calves also developed significant lesions and one of them yielded the bacteria from the lung. Three SC-vaccinated calves had slight lesions and the organism was not isolated from their lungs. The results did not consistently indicate an immunogenic potential of the soluble antigen againstP.haemolytica-related pneumonia. The effect of stress on the pathogenesis of bovine viral penumonia and correlation between pneumonic lesions and antibacterial resistancein situ are discussed.     

Porcine pleuropneumonia in Australian pigs due to Actinobacillus pleuropneumoniae serovar 5

Book reviewed in this article: Guide to the Dissection of Domestic Ruminants . RE Habel Biology and Medicine of Rabbits and Rodents . JE Harkness and JF Wagner     

Giardia infection in budgerigars

Budgerigars ( Melopsittacus undulatus ) from two different breeding colonies were found to have Giardia infection. Light microscopy, scanning electron microscopy and in-vitro and in-vivo studies confirmed the species was G psittaci . Chicks were clinically affected and showed signs of retarded growth, dehydration and diarrhoea. The faeces of adult birds treated with metronidazole in drinking water were negative for Giardia 5 days after treatment. Megabacteria were also found in adult birds but were not treated. This study extends the known host range for Giardia in Australia to include budgerigars.