Immunity following inoculation of the H120 and H52 vaccine strains of infectious bronchitis virus into the crop of the domestic fowl.

The serological responses and protection associated with inoculation of the HI20 and H52 vaccine strains of infectious bronchitis virus (IBV) into the trachea and directly into the crop of chickens were compared. Intratracheal inoculation at 3 weeks of age with HI20 resulted in the moderate log2 haemagglutination inhibition (HI) titres of 6, previously found to be characteristic of this highly attenuated vaccine strain of IBV. More than 80% of these birds gave a positive reaction to the agar gel precipitin (AGP) test.

Field observations on serological responses to vaccine strains of infectious bronchitis virus administered by coarse spray and via the drinking water.

The agar gel precipitin (AGP) and haemagglutination inhibition (HI) responses to vaccination with infectious bronchitis virus (IBV) were investigated in three flocks. The vaccines were administered by coarse spray in one large flock of commercial layers and via the drinking water in two smaller flocks of broiler breeders. In two flocks, one vaccinated by coarse spray and one vaccinated via the drinking water, the chicks had high levels of maternal antibody and failed to respond serologically to the primary vaccination at 2 to 3 weeks of age.

Immunity following vaccination with the H120 strain of infectious bronchitis virus via the drinking water.

Administration of the H120 vaccine strain of infectious bronchitis virus (IBV) via the drinking water caused mild respiratory symptoms in six out of 57 susceptible 3-week-old chickens and 45 became positive to the agar gel precipitin (AGP) test for IB. This was associated with complete protection against subsequent intratracheal challenge with the H52 strain of IBV at 11 weeks of age. The vigorous AGP response to H120 recorded here in susceptible birds contrasts with previous reports of failure of precipitins to appear following administration of water-borne IB vaccines to 1-day-old and 2-week-old chicks carrying maternally derived antibodies.

Active and passive immunisation against nephritis induced by an avian infectious bronchitis virus.

Intranasal vaccination with the H120 strain of infectious bronchitis virus (IBV) produced serum neutralisation indices of three or more in nine out of 12 birds. This afforded complete protection against intravenous challenge with the nephritogenic H52 strain of IBV and prevented the multiplication of virus in the kidney. Passive immunisation with homologous convalescent serum protected the kidney but not the respiratory tract against similar challenge.

Herpesvirus infection resembling Pacheco's disease in Amazon parrots.

Herpesvirus infection was diagnosed in two parrots that died suddenly in a pet shop. Gross lesions were confined to reddening of the small intestinal mucosa. Histological examination of tissues from one specimen revealed a hepatitis and splenitis accompanied by intranuclear inclusions.

Observations on viral tenosynovitis (viral arthritis) in Scotland.

The isolation of reoviruses from broiler breeder and layer replacement stock affected with tenosynovitis is recorded. Experimental inoculation of the reovirus isolates in Brown Leghorn chickens produced mild clinical and pathological changes. Virus isolations from the affected joints ceased 15 days after inoculation but continued until day 35 from the caecal tonsil.