Preliminary characterization of a pleomorphic gram-negative rod associated with avian respiratory disease.

An unidentified, pleomorphic, gram-negative rod (PGNR) bacterium has been isolated from domestic fowl with respiratory disease. The PGNR was isolated in 5% of turkey accessions and 3% of chicken accessions, primarily from the respiratory tract. Preliminary characterization of this organism included reviewing accession records, conducting cultural and biochemical tests, and analyzing cellular fatty acids. The PGNR was also compared with other bacteria capable of inhabiting the avian respiratory system. Biochemical and cellular fatty acid analysis failed to identify the organism, however all 14 isolates were similar.

Local reaction and serological response in commercial layer chickens injected intramuscularly in the leg with oil-adjuvanted Mycoplasma gallisepticum bacterin.

The incidence of local vaccine reaction was investigated in three flocks of commercial layer chickens after they were vaccinated intramuscularly in the leg with oil-adjuvanted Mycoplasma gallisepticum (MG) bacterin by commercial crews. Local vaccine reaction typically involved swelling due to a granulomatous cellulitis in the connective tissue above the tibiotarsal joint of the vaccinated leg. Histopathology revealed that the inflammatory reaction was confined primarily to subcutis and muscle fascia and rarely extended into muscle fibers, tendons, or tendon sheaths. Movement of the vaccinated flocks from growing to laying houses was associated with a significant increase in the incidence and severity of leg swelling. Antibodies against MG as measured by the hemagglutination-inhibition test were significantly higher in chickens with severe leg swelling than in chickens without leg swelling.

Scoliosis and tibiotarsal deformities in broiler chickens.

The incidence and degree of scoliosis were investigated in broiler chickens with and without intertarsal deformities associated with slipped gastrocnemius tendons. In both groups, the incidence of scoliosis was similar and there was a significant tendency for scoliosis to be convex on the right side. However, scoliosis was significantly greater in birds with intertarsal deformities, and in a significant proportion of these the joint with a slipped tendon was on the convex side of scoliosis. In birds with deformities, inequalities between right and left tibiotarsi were significantly greater, and tibiotarsi with greater length, narrower condyles and trochleae, and shallower trochlear grooves were significantly more often on the convex side of scoliosis. Significant positive correlations were found between scoliosis and rotational and bending deformities of the distal tibiotarsus on the convex side of scoliosis. These findings suggest a cause-and-effect relationship between scoliosis and tibiotarsal deformities associated with slipped tendons.

Relationship of sex, age, and concurrent intestinal disease to necrotic enteritis in turkeys.

A retrospective case-control study of necrotic enteritis in turkeys was done. Male flocks were involved in a significantly greater proportion of necrotic enteritis cases compared with control cases. Necrotic enteritis cases occurred most frequently between 6 and 11 weeks of age. Within this age range, the probability of a necrotic enteritis case having a concurrent intestinal disease diagnosis was significantly higher than the probability in control cases. Coccidiosis was the most frequently diagnosed concurrent intestinal disease with necrotic enteritis, followed by clinical hemorrhagic enteritis and ascaridiasis.

Coccidiosis and necrotic enteritis in turkeys.

A flock of turkey primary breeder candidates experienced increased mortality within 1 week of being placed in a growout house at 5 weeks 4 days of age. The flock was placed on wood shavings that had been used by an older flock for 2 weeks immediately before placement. Necropsy revealed severe coccidiosis and necrotic enteritis primarily in the distal jejunum, ileum, cecum, and colon. Clostridium perfringens was cultured from intestines. When breeders were selected at 17 weeks of age, total mortality in the affected flock was twice that of a comparable flock placed on fresh litter. Weight at selection in the affected flock was also significantly lower than in flocks placed on fresh litter at the same time in the same growout house.

Synovitis, osteomyelitis, and green liver in turkeys associated with Escherichia coli.

Birds in seven commercial meat turkey flocks ranging in age from 8 to 11 weeks experienced lameness with swollen joints. In addition to synovitis, the most frequent lesions were swollen liver, green liver, and osteomyelitis. Different serotypes of Escherichia coli were isolated from lesions. Histopathology revealed the absence of respiratory lesions in five flocks and the presence of enteritis in at least five flocks. Hemorrhagic enteritis virus infection was implicated in six flocks by positive serology, diagnostic histopathology, and/or clinical history. Three E. coli serotypes, isolated from different types of lesions in turkeys, were inoculated intravenously into 7-wk-old poults and produced synovitis and swollen livers 3 days postinoculation. These findings suggest that the synovitis, osteomyelitis, and green liver complex is a distinct form of disease associated with E. coli, which may result from hematogenous spread of the bacteria following hemorrhagic enteritis virus infection.

Zinc toxicosis due to ingestion of a penny in a gray-headed chachalaca (Ortalis cinereiceps).

Zinc toxicosis was diagnosed in a gray-headed chachalaca (Ortalis cinereiceps) due to ingestion of a copper-plated zinc penny. Histopathological lesions were most marked in the pancreas. These lesions included apoptosis, zymogen granule depletion, and loss of normal acinar architecture. There was also severe gizzard erosion. Heavy metal analysis revealed abnormal levels of zinc and iron in the liver. Iron pigment in the liver was most concentrated in Kupffer cells. This, along with evidence of erythrophagocytosis in the spleen, suggested that extravascular hemolysis was also associated with zinc toxicosis in this case.

Investigation of problems associated with intramuscular breast injection of oil-adjuvanted killed vaccines in chickens.

Case submissions and a field investigation indicated that oil-adjuvanted killed vaccines may produce long-lived residual lesions in chickens. The lesions typically are yellow opaque cysts along the fascial planes separating the superficial and deep pectoral muscles. Microscopic evaluation shows that most lesions are cysts with thin fibrous capsules, sometimes associated with lymphocytic aggregates and, more rarely, a granulomatous reaction.

Intranuclear inclusions of unknown pathogenic significance from diagnostic cases in three avian species.

Intranuclear inclusions were observed with light microscopy in tissues from necropsy cases from three different species of birds. Because of the nature of these inclusions, the species affected, or their distribution, the inclusions were considered of unknown pathogenic significance. The inclusions were examined ultrastructurally. Parvovirus-like particles were observed in the intranuclear inclusions of pigeon hepatocytes and duodenal stromal cells from a quail. Finely granular eosinophilic intranuclear inclusion bodies from two unrelated pigeon cases were found to be composed of loosely organized filaments. One liver sample from a 16-week-old laying chicken had prominent eosinophilic hepatocellular intranuclear inclusions composed of electron-dense coarsely granular amorphous material.

Relationship of osteomyelitis and associated soft-tissue lesions with green liver discoloration in tom turkeys.

Tom turkey carcasses with partial green discolored livers (n = 191) or normal livers (n = 198) were examined for osteomyelitis and/or associated soft-tissue lesions. Seventy-nine turkeys with green discolored livers had osteomyelitis and/or associated soft-tissue lesions (41.4%), including 53 with just osteomyelitis (27.7%), while 112 (59.6%) had no osteomyelitis and/or soft-tissue lesions. Only five turkeys (2.5%) with normal livers had osteomyelitis. Discolored livers were significantly heavier, but carcasses with discolored livers weighed significantly less than carcasses with normal livers. Bacteria were isolated from 54 of 61 osteomyelitis lesions (88.5%); most frequently staphylococci (50.8%) followed by Escherichia coli (14.8%), Streptococcus sp. (13.1%), and occasional other organisms. Most associated soft-tissue lesions and livers were sterile (74.7%). These finding indicate that although turkey carcasses with green discolored livers are more likely to have osteomyelitis and/or associated soft-tissue lesions than turkey carcasses with normal livers, there is also an approximately equal chance they will not have these lesions.

Favus in a backyard flock of game chickens.

Favus, or avian ringworm, was diagnosed in a backyard flock of game chickens from which Microsporum gallinae was isolated. Infected birds had white crusts on the comb and on the skin of the head and neck. Histopathological lesions included hyperkeratosis of the skin epithelium with invasion of the stratum corneum by fungal mycelia, acanthosis, acantholysis, and hydropic degeneration of cells in the stratum spinosum. The underlying dermis was infiltrated by mononuclear cells and contained lymphoid foci. Daily topical treatment with miconazole was applied in the field and in the laboratory, with apparent success.

Proventriculitis and ventriculitis associated with zygomycosis in ostrich chicks.

This report describes eight cases of proventriculitis and ventriculitis in ostrich chicks less than 2 months old. Clinical signs included acute onset of lethargy and anorexia in three cases, and chronic weight loss with lethargy and anorexia in four cases; no history was available in one case. There was limited antibiotic therapy in two cases; a third case was treated for giardiasis. Concurrent bacterial, yeast, and viral infections were common. Lymphoid depletion and/or necrosis of bursa, thymus, and spleen suggested severe immune challenge or immunosuppression in many cases. Histologically, there was severe ulcerative proventriculitis and ventriculitis with intralesional fungal hyphae. In two chicks with granulomatous pneumonia, similar fungal hyphae were also observed in the lung. Fungal hyphae were rarely septate, with irregular, non-parallel walls, and ranged in diameter from 7 to 20 microns. Occasional globoid distentions of the hyphae were present. Fungi were identified morphologically as species in the Zygomycetes class; in one case a Mucor sp. was cultured. Zygomycetes appear to be potentially serious opportunistic pathogens of ostrich chicks.

Femoral fractures in a young male Turkey breeder flock.

Twenty-two 32-to-35-wk-old male turkeys from a commercial breeding flock were presented to the California Veterinary Diagnostic Laboratory System, Fresno Branch, with a clinical complaint of lameness and increased mortality. Necropsy findings included a unilateral, closed oblique fracture involving the femur in 12 birds. Ten complete femoral fractures had periosteal new bone adjacent to and bridging the fracture. Periosteal callus formation, in this case, suggested that preexisting lesions preceded complete fracture of the femur. Factors such as selection for heavy body weight, lack of exercise, and handling might have contributed to the development and promotion of complete fractures.

Ornithobacterium rhinotracheale infection in turkey breeders.

A sequence of outbreaks of respiratory disease separated by intervals of about 2 wk occurred on three turkey breeder ranches. The last two ranches affected belonged to different companies and were separated by a distance of 11 km. Mortality on the last ranch was particularly severe among certain segregated groups of turkeys that included toms, heavier birds, and birds undergoing a stressful event such as artificial insemination. On this ranch, percentages of mortality within an 18-day period were 5.2% in toms, 2.4% in hens, 7.4% in heavy toms and 5.4% in heavy hens. Turkeys from 27 to 42 wk of age were examined during the outbreaks. Gross lesions included severe lung consolidation with fibrinous exudate on the pleura and air sacs, petechiae on the epicardium, and increased cloudy fluid in the pericardial sac. Liver and spleen were moderately enlarged. Histologically, there was severe fibrinoheterophilic inflammation in the airways, pleura, and air sacs and severe perivascular interstitial edema in the lungs. Liver had acute coagulative necrosis of hepatocytes associated with occasional thrombosis at the periphery of the liver lobes. Ornithobacterium rhinotracheale was isolated from tissues of the respiratory system, such as infraorbital sinus, trachea, lung, and air sacs, but not from the liver, spleen, or bone marrow. Escherichia coli was isolated less often from lung, air sac, and trachea.

Inclusion body tracheitis associated with avian adenovirus in turkeys.

Nine turkey flocks with basophilic intranuclear inclusion bodies, suggestive of adenovirus, within the epithelial cells of the tracheal mucosa were studied. Respiratory signs and increased mortality occurred in turkeys between 6 and 10 wk of age from nine commercial turkey meat flocks in central California. Necropsy findings included tracheitis and occasional mild sinusitis. Histopathology of the tracheas revealed epithelial deciliation, squamous metaplasia, large basophilic intranuclear inclusion bodies within epithelial cells, and lymphoplasmatic inflammation in the mucosa. Electron microscopy of the mucosa revealed hexagonal viral particles, approximately 73 nm in diameter, consistent with adenovirus within the nuclei of epithelial cells. All tracheal sections were negative for adenovirus group II by specific immunoperoxidase staining. Adenovirus group I was isolated from the trachea. In addition, Bordetella avium, Ornithobacterium rhinotracheale, and Klebsiella pneumoniae were isolated from the tracheas of three, three, and two flocks, respectively. Statistically greater total mortality and a smaller percentage of marketed turkeys were observed in the submitted flocks than in randomly selected flocks. No significant difference was observed between the two turkey groups in market weight, feed conversion, or percentage of grade "A" turkeys.

Infectious coryza in meat chickens in the San Joaquin Valley of California.

Two cases of infectious coryza in meat chickens are reported. The first case involved 6-week-old broiler chickens in which only Haemophilus paragallinarum was isolated. The second case involved 11-week-old roaster chickens in which H. paragallinarum and Mycoplasma synoviae were isolated. Both farms were in close proximity to layer-chicken farms where infectious coryza had been previously diagnosed. In both cases, only certain houses on the farm were affected, and mortality in these houses increased slightly. At processing, the condemnation rates for affected houses were considerably higher than rates for unaffected houses. Condemnations for affected houses were mostly due to airsacculitis. A dissecting fibronopurulent cellulitis was a prominent lesion in the second case. This lesion could lead to confusion with chronic fowl cholera and swollen-head syndrome.

Recurrent transient paresis in a turkey flock.

Recurring episodes of extreme leg weakness and associated mortality were documented in a turkey flock at 8 to 15 weeks of age. Flock mortality attributed to posterior paresis was approximately 12%, or 4800 of 40,000 turkeys. Four of six open-confinement units were affected. Gross and histological examinations revealed no significant lesions. Immunology and virology were uninformative. There were no significant differences in serum chemistry between clinically affected and normal turkeys. Testing of feed, water, soil, and tissues revealed no common toxicants. Isolation and supportive care for affected turkeys, both in the laboratory and in the field, frequently resulted in full recovery. Injection of a test group of affected turkeys with Type C botulism antitoxin appeared to enhance recovery. However, repeated attempts to detect botulism toxin in serum, liver, or cecal contents using mouse bioassay procedures were unsuccessful.

Severe mortality in broiler chickens associated with Mycoplasma synoviae and Pasteurella gallinarum.

Severe economic loss due to high mortality and condemnation rates occurred on two commercial broiler facilities. Chickens had moderate-to-severe airsacculitis, pericarditis, perihepatitis, tracheitis, and synovitis. Pasteurella gallinarum was isolated from 16 of 18 pericardia, four of 14 livers, 11 of 16 air sacs, six of seven joints and one of 28 tracheas in pure culture. In addition, Mycoplasma synoviae was isolated from trachea and air sac. Lesions were suggestive of an Escherichia coli septicemia, but E. coli was isolated from only four of 28 tracheas and one of 14 livers in pure culture. A coronavirus was isolated from trachea and lung. Whether this coronavirus represented a vaccine or field strain of infectious bronchitis was not determined. These findings suggested that the severe lesions were due to a concomitant infection with an atypical strain of P. gallinarum.

An atypical strain of Pasteurella gallinarum: pathogenic, phenotypic, and genotypic characteristics.

The pathogenicity of a strain of Pasteurella gallinarum isolated in Fresno County, Calif., was compared with the American Type Culture Collection (ATCC) strain. Broiler chickens were inoculated intranasally with 10(7) colony-forming units (CFU) and intramuscularly with 10(5) CFU of each strain. The only notable lesions were in chickens inoculated intramuscularly with 10(5) CFU of the Fresno strain, which developed severe myositis at the inoculation site, pericarditis, perihepatitis, airsacculitis, and synovitis. P. gallinarum was reisolated from these lesions. Phenotypic characteristics of the two strains were identical except in reactions in ONPG broth and fermentation of xylose. Protein-banding patterns for the two strains were identical except for a single band difference in the 35-kilodalton region. Restriction endonuclease analysis confirmed that the Fresno strain was a distinct one. Plasmid analysis revealed that the ATCC strain had two plasmids and the Fresno strain had none.