G. L. Cooper

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.

Periodic recurrence of gangrenous dermatitis associated with Clostridium septicum in a broiler chicken operation

The association of gangrenous dermatitis (GD) of chickens with Clostridium septicum infection was well documented in the United States during the 1960s (Bickford AA: 1971, Proc 20th Western Poult Dis Conf, pp. 6, 7). At about the same time, GD was recognized as a source of considerable economic loss to broiler production operations in the United Kingdom and Australia. 1,3 Subsequently, the potentiating role of immunosuppression induced by infectious bursal disease virus (IBDV) and other viral agents was recognized. Reduction of losses caused by GD requires control procedures for IBDV and other immunosuppressive agents. Recent reports have suggested that there may be an increased incidence of the clostridial diseases of chickens in the United States. Among these diseases, GD associated with C. septicum is a major concern. At the California Veterinary Diagnostic Laboratory System (CVDLS), Turlock Branch, the diagnosis of this disease was once as frequent as 5% of all diagnostic cases (Bristow DL: 1971, Proc 20th Western Poult Dis Conf, p. 11). After producers implemented procedures to limit the effects of IBDV, the diagnosis of GD became a rare event in California. This report documents an unusual annual recurrence of C. septicum-associated GD over 3 consecutive years in a single house of a multiple-house broiler facility. The ranch involved in this report is situated on flat delta valley terrain and consists of 8 broiler houses. The houses are similar in design but differ in size. Three houses are 10,000 sq ft, 3 are 15,000 sq ft, and 2 are 17,500 sq ft. Feed sources, feed delivery systems, ventilation systems, and litter management procedures are uniform on the ranch. A single well serves as the water source for all houses, and hot-water brooding is practiced in all houses. The ranch is operated on a year-round all-in, all-out basis. On February 3, 1993, 7 dead 43-day-old broiler chickens were submitted from house 5 (15,000 sq ft) to CVDLS, Turlock Branch, for necropsy. Mortality in the house had increased suddenly to about 1% per day. Stocking density in all three 15,000-sq-ft buildings had been 19,000 chicks at placement. This density is approximately 8.5% higher than normal for these houses. Climatic conditions were normal for winter with characteristically high humidities and cool temperatures. Litter conditions in the house were described as old and wet. On January 18, 1994, a similar group of 6 dead broiler chickens was submitted from house 5. A sudden increase in mortality had occurred in this house only. The birds were

The Diagnosis of Very Virulent Infectious Bursal Disease in California Pullets

Abstract This report documents the occurrence of a very virulent infectious bursal disease virus (vvIBDV) in Northern California commercial brown pullets. Diagnosis was made from multiple accessions from two neighboring and epidemiologically related ranches submitted to the California Animal Health and Food Safety (CAHFS) laboratory. Pullets, 11 and 14 wk of age from ranch A (rA) and ranch B (rB) respectively, were submitted from infectious bursal disease virus vaccinated flocks experiencing a drastic increase in mortality. The December 2008 outbreak resulted in 26% and 34% mortality on rA and rB respectively. Gross and histologic lesions characteristic of acute vvIBDV were observed. Gross lesions included edematous bursas, hemorrhages at the junction of the proventriculus and gizzard as well as hemorrhages on skeletal muscles. Microscopic lesions included severe lymphoid necrosis and inflammation in edematous bursas, lymphoid necrosis in thymus, spleen, Peyers patches and cecal tonsils. Diagnosis of vvIBDV was confirmed by molecular characterization of the IBDV from bursas as well as viral pathogenicity in specific-pathogen-free birds. RT- PCR and nucleotide sequencing of the hypervariable region of the VP2 (vVP2) gene segment of the IBDV genome was performed on rA, rB and embryo passaged rA virions.The amino acids compatible with vvIBDV isolates: 222(Ala), 242(Ile), 256(Ile), 294(Ile) and 299(Ser) were reported from both ranches. In addition, nucleotide sequencing of a fragment of the VP1 gene demonstrated the viruses have the segment B genotype associated with highly pathogenic vvIBDV. Inocula of 105.5 50% egg infective dose of vvIBDV virus from rA and rB were introduced orally into two groups (g1 and g2 respectively) of 4 wk 2-day-old SPF leghorns. At 4 days postinoculation, there was 100% (22/22) morbidity in g1 and g2; 91% (20/22) mortality in g1; 100% (22/22) mortality for g2; 0% (0/20) morbidity and 0% (0/20) mortality was reported in the control group. This is the first occurrence of vvIBDV reported from birds in the United States.

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.

Avian Paramyxovirus Type 1 Infections in Racing Pigeons in California. I. Clinical Signs, Pathology, and Serology

An outbreak of diarrhea and neurological disease in California racing pigeons caused by avian paramyxovirus type 1 (PMV-1) is documented. Predominant clinical signs were polydipsia, ataxia, poor balance, torticollis, head tremors, inability to fly, and diarrhea that was unresponsive to therapy. Gross pathologic findings were often unremarkable or non-specific. The predominant histologic lesions were interstitial nephritis, chronic tubular necrosis, lymphoplasmacytic infiltration within the kidney, liver, and pancreas, and focal non-suppurative encephalitis. Pigeons from 20 submissions demonstrated characteristic clinical signs of PMV-1 infection. Pigeons from 17 submissions exhibited typical histopathology. Serologic evidence of PMV-1 infection was present in pigeons from 13 submissions, and PMV-1 was isolated from pigeons received in six submissions. None of these pigeons had been vaccinated against PMV-1.

An outbreak of infectious laryngotracheitis in California broilers.

Infectious laryngotracheitis (ILT) was diagnosed as the cause of an outbreak of respiratory disease in broiler chickens in California. The classical form of ILT is characterized by dyspnea, gasping, coughing, and expectoration of bloody exudate. Most of the broilers submitted to the diagnostic laboratory showed a non-classical presentation of ILT, in which mucoid tracheitis and conjunctivitis were the most consistent lesions. Historically, most of the ILT cases diagnosed in our laboratory have consisted of layers with classical signs and lesions. It is not known whether this non classical presentation of ILT in broilers is due to differences in the way broilers respond to ILT infection or to the nature of the ILT virus isolate.

Listeriosis in California broiler chickens.

of three techniques for detecting bovine herpesvirus type 1 (BHV1) in naturally and experimentally contaminated bovine semen. Zuchthygiene 23:1-9. 3. Darcel CLQ, Coulter GH: 1976, IBR neutralizing substance in bull seminal fluid and its removal prior to attempts at virus isolation from semen. Can Vet J 17:317-343. 4. Kahrs RF, Johnson ME, Bender GM: 1977, Studies on the detection of infectious bovine rhinotracheitis (IBR) virus in bovine semen. Proc Annu Meet Am Assoc Vet Lab Diagn 20:187-208. 5. Kahrs RF, Littell RC: 1980, Detection of viruses in bovine semen. Influence of preparative centrifugation on isolation of IBR virus. Proc Annu Meet Am Assoc Vet Lab Diagn 23:251-262. 6. Loewen KG, Darcel CLQ: 1985, A comparison of two methods for the isolation of bovine herpesvirus 1 (BHV-1) from extended bovine semen. Theriogenology 23:935-939. 7. Moorthy ARS: 1985, Outbreak of balanoposthitis in breeding bulls. Vet Rec 116:98. 8. Schultz RD, Sheffy BE: 1980, Current status of viral infection of bovine genital tract with emphasis on IBR/IPV virus. In: Current therapy in theriogenology, ed. Morrow DA, pp. 503-509. W. B. Saunders Co., Philadelphia, PA. 9. Snowdow WA: 1965, The IBR/IPV virus reaction to infection and intermittent recovery of the virus from experimentally inoculated cattle. Aust Vet J 41:135-142.

Enterococcus durans infection in young chickens associated with bacteremia and encephalomalacia.

Two unrelated flocks of chicks experienced elevated mortality from 4 to 10 days of age. Clinical signs in affected birds included a full range of neurological disorders. Livers and spleens were grossly enlarged at necropsy. Enterococcus durans was isolated from multiple organs, including brains. Histologically, there were multifocal coagulative necrosis in the liver, areas of malacia in brain stem, and cerebellar white matter. Inoculation of 1-day-old chicks with a suspension of E. durans resulted in bacteremia but did not produce the lesions observed in field cases.

Skeletal Myopathy Produced with Experimental Dosing of Turkeys with Monensin

Monensin was given via gavage to 5- and 6-week-old broad-breasted white turkeys. The birds were allotted into four groups--three groups given monensin and one group of controls--in two experimental trials. Treated turkeys in Trial 1 received one dose of monensin per day for 4 days at 4.7 mg monensin/kg body weight, 8.8 mg/kg, or 17.6 mg/kg. Treated turkeys in Trial 2 received one dose of monensin per day for 5 days at 1.93 mg/kg, 4.7 mg/kg, or 8.8 mg/kg. Turkeys receiving the lowest dose showed no clinical signs of myopathy. Birds receiving 4.7 mg monensin/kg developed ataxia after the third dose and rear limb paresis and paralysis after the fifth dose. Turkeys receiving 8.8 mg/kg were ataxic after the second dose and paretic or paralyzed after the fourth dose. Turkeys receiving 17.6 mg/kg were ataxic 3 hours after the first dose and paretic or paralyzed 8 hours after the first dose. Histologically, a necrotizing skeletal myopathy was present in the muscles of the rear limbs. A dose-related response was observed in the percentage of myofibers damaged in birds that survived until the end of the trials. Intrafiber edema and vacuolation were observed in histologic sections from myocardium of turkeys from the two highest dose groups.

Several outbreaks of Yersinia pseudotuberculosis in California turkey flocks.

Yersinia pseudotuberculosis has been isolated from a wide range of animal species, both wild and domestic, but few references to turkeys can be found in literature. The first report of the disease in turkeys in the United States came from Rosenwald and Dickinson (9), who isolated the organism from 10 turkey flocks in Oregon in 1940-1941. In 1946, Blaxland (3) described outbreaks on eight turkey ranches in England, and in 1954, Mathey and Siddle (8) isolated the organism from a turkey in California. Kilian et al. (7) reported an isolation from a turkey hen in Oregon in 1954. In 1972, Wise and Uppal (11) described an outbreak of Y. pseudotuberculosis-induced osteomyelitis in turkey farms in England. The present report describes outbreaks of Y. pseudotuberculosis-induced septicemia and osteomyelitis in California turkey ranches.