Vaccination of ring-necked pheasant for marble spleen disease.

Laboratory evidence indicates that a safe and effective procedure was developed for vaccinating pheasants against marble spleen disease. Field trials confirm the safety of the vaccine and suggest that vaccination will prevent marble spleen disease. Vaccination is by drinking-water administration of turkey-spleen-propagated turkey-origin live avirulent virus to pheasants 4 1/2 weeks old or older. The effect of field vaccination was studied in 39,000 pheasants in pens where recurrent annual mortality had been 5-15%.

A case of acute pulmonary edema, splenomegaly, and ascites in guinea fowl.

Acute pulmonary edema, splenomegaly, and ascites were observed in a disease outbreak in adult white and pearl guinea fowl. The clinical history and gross and microscopic lesions resembled those described for marble spleen disease of pheasants and avian adenovirus group II splenomegaly of chickens. A small number of intranuclear inclusion bodies were found in liver, spleen, and lung sections of affected guinea fowl. Attempts to isolate virus and serological tests to detect the presence of viral antigens were unsuccessful. Adult female pearl guinea fowl experimentally exposed to pheasant and turkey isolates of type II avian adenoviruses developed gross and microscopic lesions similar to those seen in the field outbreak. The pheasant isolate was the more virulent. Intranuclear inclusion bodies were observed in liver, spleen, and lung sections of pearl guinea fowl inoculated with either of the virus isolates, and direct immunofluorescent examination revealed viral antigen in the spleen and lung.

Cataracts and crooked toes in Brahma chickens.

In 1991, 69% of the cockerels and 15% of the pullets in an inbred flock of approximately 200 dark and light Brahma chickens had unilateral or bilateral cataracts and crooked toes. Affected chickens were normal at hatching but developed cataracts with or without crooked toes by 6 months of age. The cataracts were initially focal and polar but progressed to be diffuse throughout the lenticular cortex. The crooked toes involved one or more of the second, third, and fourth digits and were due to a medial deviation of the distal aspect of the first phalanx. The cataracts and crooked toes were considered likely due to a hereditary defect, based on the following: the history of flock inbreeding; the lack of historical, clinical, or pathological evidence of avian encephalomyelitis or Marek's disease; the presence of lesions only in Brahma chickens and not in the approximately 200 other chickens on the farm kept under the same management and environmental conditions; the age at which the lesions occurred; and the nature of the lesions.

Experimentally induced necrotic enteritis in chickens.

A 1.3 to 10% incidence of necrotic enteritis was experimentally produced in broiler-type chickens in three of five trials. The incidence range observed was considerably narrower and lower than the 5.6-37.3% range reported in the literature. Clostridium perfringens was inconsistently isolated from the liver and intestine of dosed chickens.

Infectious tenosynovitis in commercial White Leghorn chickens.

Infectious tenosynovitis was diagnosed in three separate outbreaks in a commercial White Leghorn hens, though not previously reported in adult White Leghorns (3). Clinically affected flocks had decreased production and increased daily mortality, with many hens showing signs of the so called "cage-fatigue bluecomb" syndrome. Most sick birds had lesions typical of infectious tenosynovitis, with pronounced cyanosis and dehydration. Dead birds had signs of acute septicemia. The course of the disease (about 8 weeks) was not altered by the medicinal regimens tried. Young laying-age flocks were most seriously affected. Production losses averaged 15 to 20%, and mortality reached 5% per month during the recovery phase.

Vaccination with F-strain Mycoplasma gallisepticum to reduce production losses in layer chickens.

The effect of Mycoplasma gallisepticum (MG) infection or vaccination of Conn. F-strain MG on 45 weeks of egg production was analyzed using production records from 132 flocks of commercial layer hens. The flocks were located in Pennsylvania, and the data were collected for two years. On the average, layers maintained free from infection with MG laid 15.7 more eggs/hen housed than the MG-infected layers; figures were adjusted for layer-strain effect. This adjusted advantage decreased to 8.7 eggs/hen housed when uninfected flocks were compared with vaccinated flocks. Adjusted average production of vaccinated flocks was 7.0 eggs/hens housed more than production of MG-infected flocks. Egg production of four layer strains was observed with respect to vaccination or natural infection with MG. The four strains responded similarly whether vaccinated or infected. Route of vaccination and age of layer at time of vaccination influenced egg production of vaccinated birds. The adjusted average production/hen housed was 4.9 eggs greater for birds vaccinated via drinking water than for birds vaccinated via spray. The adjusted average was 10.3 eggs/hen housed greater for birds vaccinated between 8 and 18 weeks of age than for birds vaccinated after 18 weeks.

Use of amprolium for the control of coccidiosis in pheasants.

Amprolium administered in feed during the first 4 weeks of life at a level of 0.0175% protected pheasants against three major pathogenic species of coccidia (Eimeria colchici, E. duodenalis, and E. phasiani) when they were exposed at 2 weeks of age. The difference was significant when mortalities were compared between medicated infected (3%) and unmedicated infected (35%) pheasants. The manufacturer's proposed level (0.0175%) and twice the proposed level (0.0350%) of amprolium had no significant effect on weight gains or mortality in the safety trial. Amprolium residues found in the muscles and livers of pheasants that received either level of amprolium did not exceed the tolerance levels for chickens and turkeys permitted by the U.S. Food and Drug Administration.

Necropsy of chickens, turkeys, and other poultry.

Necropsy of dead or terminally ill birds is a key approach to disease diagnosis. It is important that one establish an orderly, consistent necropsy procedure and evaluate gross lesions as to their likely cause and significance. A very high percentage of farm flock poultry maladies can be diagnosed by gross lesions plus a few simple laboratory procedures, such as direct microscopy, Gram's stain, fecal flotation, and aerobic bacteriology.