Diseases of the Respiratoey Tract in Fowls

Problems Relating to the Differential Diagnosis and Control of Respiratory Disease in Poultry

“…The possible roles of other organisms such as H . gallinamtm and the filter passing agent demonstrated by Hart (1946) in New South Wales must also be considered . Although Seddon (1953) considers that the disease investigated by Hart was probably identical with ' ' Chronic Respiratory Disease," the possibility that Hart's filter passing agent was a true virus cannot be escluded.…”

Characterization of Avian Mycoplasma

“…They concluded that it was a strain of pleuropneu monia-like organisms. Crawley (67) in Canada, by Garust and Nobrega (73) In Brazil, by Quizon (146) in the Philippines, by Pathak and Singh (144) in India, by Cottew (3*+) and Hart (92) in Australia, by Tajima et al (162) in Japan, by Chu (28,29) in England, by de Blieck (40) in the Netherlands, by Hartwigk (94,95) in Germany, by Strieker and Fisera (158) in Czechoslovakia, by…”

Respiratory Diseases of Poultry

“…because they pass through Berkfeld V and N filters, Selas 02, Mandler 6 and 7, though they will not pass Berkfeld W and Selas 03. Hart (1946) in a report to this Association of some excellent work described two groups of "virus" disease which were distinct from laryngotracheitis, fowl pox and coryza. In the light of subsequent observations, it has becn suggested (Seddon 1952) that these were, in fact, cases of C.R.D.…”

“…This reverses findings by Beach (1934). and Hart (1946), who found that strains of laryngotracheitis with low virulence for the trachea were unsatisfactory to use as cloaca1 vaccines. Hunt ( 1959) isolated a laryngotracheitis virus which had the capacity to produce good intrafolliculer takes on the skin of chickens but with a low virulence for the trachea.…”