Survival of exotic Newcastle disease virus in commercial poultry environment following removal of infected chickens.

During the first weeks of 2003, after exotic Newcastle disease (END) was confirmed in commercial layer flocks in Southern California, it became apparent that the virus survival information in the literature varied widely and was difficult to extrapolate to current local conditions. The END Task Force used the information available in the literature and the recommendations of research scientists to establish protocols for safely handling manure from infected and depopulated premises. In an attempt to gain more applicable knowledge in the management of contaminated poultry manure in the course of the END outbreak, this virus survival study was designed and implemented.

Comparison of fecal samples collected per rectum and off the ground for estimation of environmental contamination attributable to beef cattle.

Objectives: To determine whether sampling feces off the ground replicates prevalence estimates for specific pathogens obtained from fecal samples collected per rectum of adult cows, and to determine characteristics of feces on the ground (fecal pats) that are associated with subsequent identification of Campylobacter spp, Cryptosporidium parvum, and Giardia duodenalis.

Animals: A random sample of adult beef cattle from 25 herds located throughout California.

Procedure: 1,115 rectal and ground fecal samples were obtained.

Specificity of assays used by regulatory agencies to detect antibiotic residues in tissues of culled dairy cows.

Objective: To determine percentage of false-positive test results for assays used by regulatory agencies to detect antibiotic residues in tissues.

Design: Prospective study.

Animals: 426 dairy cows.

California National Animal Health Monitoring System for meat turkey flocks-1988-89 pilot study: management practices, flock health, and production.

A pilot project for a meat turkey National Animal Health Monitoring System was undertaken in California in 1988-89 to explore data gathering techniques and to estimate the frequency, magnitude, and variability of management, flock health (including administration of pharmaceuticals for prevention and treatment of disease), and production variables in order to facilitate planning for future food animal monitoring systems. Enteritis, which occurred in over one-third of the flocks, and colibacillosis, which occurred in nearly one-quarter of flocks, were the most common diseases reported. Mycoplasma synoviae was reported in two flocks and Mycoplasma gallisepticum and Mycoplasma meleagridis each were reported in one flock.

Mass screening of cattle sera against 14 infectious disease agents, using an ELISA system for monitoring health in livestock.

Mass screening ELISA methods were developed for testing cattle serum for antibodies against 14 common livestock diseases simultaneously. The absorbance values were transformed to a %ELISA (spectrophotometric antibody end point) by a computer interfaced with a microplate reader. A histogram indicating a cutoff point and a report for the veterinarian also was generated.

Health survey of backyard poultry and other avian species located within one mile of commercial California meat-turkey flocks.

A survey was conducted to characterize domestic and exotic bird populations, estimate seroprevalence to selected disease agents, and describe health management practices on 62 premises containing "backyard" flocks located within one mile of 22 commercial California meat-turkey flocks participating in National Animal Health Monitoring System (NAHMS). Chickens were present on 56 backyard premises and turkeys on seven. Antibodies were identified against Mycoplasma gallisepticum, M.

Expenditures for veterinary services and other costs of disease and disease prevention in 57 California beef herds in the National Animal Health Monitoring System (1988-1989).

Data on costs associated with episodes of disease and disease prevention, including expenditures for veterinary services, were collected from 57 California beef cow-calf herds during 1988-1989 as part of the National Animal Health Monitoring System. Mean cost associated with episodes of disease was $33.90/cow-year, with $0.

Veterinary and nonveterinary costs of disease in 29 California dairies participating in the National Animal Health Monitoring System from 1988 to 1989.

Twenty-nine California dairy herds were studied over a 12-month period from 1988 to 1989 as part of the National Animal Health Monitoring System. Monthly interviews administered to dairy producers were used to measure the costs of all health-related expenditures and disease incidence in these herds. Of the total $1,523,558 reported, $1,355,467 (89%) was attributed to cost of disease events and $168,091 (11%) to cost of disease prevention.

Prevalence of trichomoniasis among California beef herds.

Sixty cow-half herds of more than 50 cows each were randomly selected for a prevalence survey of bovine trichomoniasis in California. Herd size, as judged by the number of bulls, ranged from 1 to 210 bulls (median = 8; mean = 59 +/- 15.8).

Epizootiologic study of bluetongue: virologic and serologic results.

Heparinized blood and serum samples were obtained from 1,295 ruminants in herds or flocks with bluetongue virus (BTV) infection in 4 western states. Submissions were from herds or flocks with clinical bluetongue (BT), as well as from animals on premises with no history of BT disease. Insects, including Culicoides variipennis, were collected in areas enzootic for BT disease.

Methods of spread of velogenic viscerotropic Newcastle disease virus in the southern Californian epidemic of 1971-1973.

Data collected during the velogenic viscerotropic Newcastle disease (VVND) epidemic that occurred in southern California from 1971 to 1973 were analyzed to determine the methods of spread of the disease. Spread between chicken flocks was extensive and due mainly to the movement of live birds and mechanical transport of virus by man, especially by vaccination and poultry service crews. Spread to exotic birds was from contact with infected imported stock.