Biomedical subjects

R L Walker

Publications and source records attributed to R L Walker.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Serotypes of Salmonella isolated from California turkey flocks and their environment in 1984-89 and comparison with human isolates.

Serotypes of Salmonella from turkeys and their environment identified at the California Veterinary Diagnostic Laboratory System (CVDLS) between 1984 and 1989 are reported. Between 1988 and 1989, Salmonella serotypes from turkeys were compared from two sources: from routine submissions to the CVDLS (primarily associated with the National Poultry Improvement Plan), and from a random sample of turkey farms conducted by the National Animal Health Monitoring System (NAHMS). Serotype isolation frequencies were ver similar under these two systems. Serotypes identified most frequently under both systems were (listed from most to least frequent): Salmonella kentucky, S. anatum, S. heidelberg, S. reading, and S. senftenberg. This isolation pattern was different from that found in humans in California; only S. heidelberg was relatively common in both humans and turkeys during this period.

Animals↗

PubMedDate not supplied

Efficacy of miconazole nitrate against favus in oriental breed chickens.

Miconazole nitrate 2% was tested for its efficacy against Microsporum gallinae (the causative agent in favus) in a flock of various Oriental breed (Shamo and Aseel) and crossbreed chickens. Six adult males showing clinical signs of favus were randomized into control and experimental groups. The males were maintained on individual tiecords on the range, with no physical contact between birds. The experimental birds had the affected areas washed with soap and water and dried, and an ointment of miconazole nitrate 2% was applied. The experimental birds received the treatment twice a day for 34 days. Scrapings from the affected areas of all birds were cultured at the beginning and end of the test. At the end of the treatment period, the control birds were still positive for M. gallinae, but the organism could not be cultured from the treated birds.

Administration, Topical↗

PubMedDate not supplied

Salmonella enteritidis, phase type 4 infection in a commercial layer flock in southern California: bacteriologic and epidemiologic findings.

Salmonella enteritidis, phage type 4 (SE PT4), was isolated from five of six 27-wk-old layer chickens submitted for necropsy from a flock of 43,000. Bacteriologic and epidemiologic investigations on the ranch revealed that five of the eight flocks (n = 176,000) were infected. The prevalence of SE PT4 in randomly selected healthy birds ranged from 1.7% (in caged birds) to 50% (in free-range birds) and prevalence in culled birds (kept on dirt floor houses) ranged from 14% to 42%. The estimated overall prevalence of group D Salmonella in eggs contaminated with group D Salmonella was 2.28 per 10,000. The estimated prevalence of group D Salmonella in eggs from caged birds in three infected houses ranged from 1.5 to 4.1 per 10,000, whereas in two houses of free-range birds, prevalence was 14.9 to 19.1 per 10,000. Three of the eight flocks on the ranch remained negative for Salmonella between May 1994 and December 1995 or until removed from the ranch. Salmonella enteritidis PT4 was also isolated from 12.5% (6 of 48) of mice; 57% (four of seven) of cats; and two of two skunks tested. Environmental drag swabs and well water samples yielded multiple serotypes of Salmonella (23/180 and 5/14, respectively) but not S. enteritidis.

Animals↗

PubMedDate not supplied

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.

Animals↗