Search PubMed⌕ Search

Biomedical subjects

G L Cooper

Publications and source records attributed to G L Cooper.

52 records · Page 3Linked to original sources
PubMedDate not supplied

Clinical, pathological, and epizootiological features of long-segmented filamentous organisms (bacteria, LSFOs) in the small intestines of chickens, turkeys, and quails.

Long-segmented filamentous organisms (LSFOs) are easily recognized gram-positive bacteria that infect several species of animals. The present study describes the epizootiological, clinical, and pathological characteristics of LSFOs in chicks, turkey poults, and quails in Georgia and California. LSFOs are most likely to be seen in young poultry that have gastrointestinal illnesses during winter. Concomitant infections with other bacteria and protozoans are common. Although inflammation and displacement of microvilli are characteristics of LSFO infections in these birds, LSFOs are not necessarily pathogens. They may be normal intestinal flora or commensal organisms that overgrow when certain unknown gastrointestinal conditions are correct or certain unknown events occur.

Animals↗
PubMedDate not supplied

Systemic trichomoniasis in a squab operation.

Systemic trichomoniasis was responsible for severe morbidity and mortality in a commercial squab operation. Squabs of 1 to 3 weeks of age were primarily affected. Extensive caseous necrosis of the liver, heart, lung, and intestinal mesentery was observed grossly. Histologically, extensive heterophilic inflammation surrounded the necrotic areas and was observed perivascularly in areas that were uninvolved grossly. Numerous trichomonads were demonstrated in affected tissues with Bodian's silver stain.

Animals↗
PubMedDate not supplied

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.

Air Sacs↗
PubMedDate not supplied

An encephalitic form of listeriosis in broiler chickens.

A disease outbreak characterized by torticollis, incoordination, and depression was seen in a commercial broiler operation in California. Listeria monocytogenes was isolated from brain tissue with some degree of difficulty, and only after culturing directly from the brain stem. No evidence of concurrent disease was found, and the source of the outbreak was undetermined.

Animals↗
PubMedDate not supplied

Pasteurella anatipestifer infections in California turkey flocks: circumstantial evidence of a mosquito vector.

Outbreaks of Pasteurella anatipestifer infections in California turkey flocks were investigated and found to have a seasonal distribution, with a peak incidence in fall, coinciding with peak Culex mosquito populations. An experiment was conducted to test the hypothesis that mosquitoes may serve as vectors for P. anatipestifer infections in turkeys. Four 7-week-old turkey poults were exposed for 7 days to mosquitoes captured from turkey barns during a field outbreak of P. anatipestifer serotype 1 infection. One turkey developed serum antibodies to serotype 1, detectable by enzyme-linked immunosorbant assay, and was resistant to an intravenous inoculation of P. anatipestifer serotype 1 at 4 weeks postexposure. Giemsa-stained blood smears from this bird and from three 7-week-old turkeys inoculated intravenously with P. anatipestifer revealed the presence of rod-shaped bacteria in or on the surface of host erythrocytes. No such rod-shaped bodies were found on erythrocytes of an uninoculated control turkey.

Animals↗
PubMedDate not supplied

Enteritis in turkeys associated with an unusual flagellated protozoan (Cochlosoma anatis).

Outbreaks of enteritis associated with an unusual flagellated protozoan occurred in six California turkey flocks during the summer of 1992. Certain morphological and ultrastructural details of the parasite, which resembles Cochlosoma anatis, are illustrated with scanning and transmission electron micrographs. The flagellate attached to the intestinal mucosa by means of a sucker-like apparatus, and circular impressions of the sucker were created on the surface epithelium. Histological lesions were characterized by blunting and fusion of villi; cellular infiltration of the lamina propria with lymphocytes, plasma cells, histiocytes, and heterophils; and increased numbers of mitotic figures in crypt epithelium.

Animals↗
PubMedDate not supplied

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.

Animals↗
PubMedDate not supplied

Spirochetosis in California game chickens.

An outbreak of spirochetosis occurred in a flock of 75 game chickens in California during fall 1991. Affected birds were weak and anemic. Many had greenish diarrhea. Spirochetes were seen on Giemsa-stained blood smears and in silver-stained tissue sections of kidney, liver, and spleen. Splenomegaly, which is reported to be characteristic of fowl spirochetosis, was not observed in two acutely infected chickens.

Animals↗
PubMedDate not supplied

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.

Animals↗
PubMedDate not supplied

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.

Animals↗
PubMedDate not supplied

Ascaridia dissimilis larval migration associated with enteritis and low market weights in meat turkeys.

A meat turkey ranch had a history of producing flocks with low market weights. Live bird samples and environmental samples from the ranch were collected over a period of eight months and analyzed at the California Veterinary Diagnostic Laboratory System-Turlock Branch. The disease condition consistently present was enteritis associated with Ascaridia dissimilis infection in birds from growout houses. After aggressive control measures for A. dissimilis were implemented, subsequent flocks reached expected market weights.

Animal Husbandry↗
PubMedDate not supplied

Esophageal trichomoniasis in chickens.

Esophageal trichomoniasis has been rarely reported in chickens. At the California Veterinary Diagnostic Laboratory System-Turlock Branch, this disease was recently diagnosed in two cases submitted from backyard chicken flocks. The esophageal lesions observed were similar to those seen in several other important diseases of chickens. The causative trichomonad organisms were readily demonstrated on wet smears and by histologic studies. In both cases, the investigated flocks were afflicted with several concurrent diseases. California has experienced an increase in the number of small nontraditional chicken production operations. These facilities are sometimes in close proximity to commercial poultry operations and biosecurity barriers occasionally fail. The poor husbandry practices often used in these small flocks make them a potential reservoir for rare diseases such as trichomoniasis and also for disease organisms that are devastating to commercial poultry.

Animals↗
PubMedDate not supplied

Experimental infection of turkey poults with western equine encephalitis virus.

The pathogenicity of a field isolate of western equine encephalitis (WEE) virus, which was recovered from a breeder hen during investigations of egg production drops in California turkey flocks, was tested in 2-wk-old turkey poults. No symptoms or mortality were observed in poults inoculated intramuscularly with 4.2 log10 50% embryo lethal doses of virus; however, the infection did result in mild to moderate lymphoid necrosis in the bursa of Fabricius and thymus glands beginning on the first day postinoculation. In addition, WEE virus could be isolated from the blood of infected poults for up to 3 days postinoculation.

Animals↗
PubMedDate not supplied

Sticktight fleas associated with fowl pox in a backyard chicken flock in California.

A mixed breed rooster, from a backyard flock of 13 chickens, was received at California Veterinary Diagnostic Laboratory System-Turlock Branch for postmortem examination. The bird presented with thickened, featherless, scab-encrusted skin around the head region. Numerous sticktight fleas were found attached to the encrusted skin. Microscopic evaluation of the skin revealed a lymphoplasmacytic reaction in the dermis with visible embedded flea mouthparts. Also noted histologically in this region were epidermal hyperplasia and ballooned epidermal cells containing intracytoplasmic inclusions indicative of fowl poxvirus.

Animals↗
PubMedDate not supplied

Pasteurella multocida infection involving cranial air spaces in White Leghorn chickens.

Seven 18-wk-old pullets from a commercial layer flock experiencing increased mortality associated with neurologic and respiratory symptoms were submitted to the California Veterinary Diagnostic Laboratory System at the Turlock Branch for necropsy. Clinical signs included depression, torticollis, swollen eyelids, conjunctivitis, and sinusitis. Meningoencephalitis and suppurative inflammation of the cranial air spaces were found on histopathology. The brain, sinuses, and air spaces of the cranium were infected with Pasteurella multocida. Complicating the condition was Mycoplasma gallisepticum infecting the sinus and paramyxovirus-I affecting the trachea.

Animals↗