Biomedical subjects

D W Hird

Publications and source records attributed to D W Hird.

At least 73 records · Page 4Linked to original sources

PubMed1986

Salmonellosis in hospitalized horses: seasonality and case fatality rates.

Salmonellosis was studied during an 11-year period (July 1971 through June 1982) in 245 hospitalized horses. Ten years' data (207 cases) were analyzed in a time series study. Peak seasonality of the disease was from June through September. The cycle curve revealed 3 major outbreaks, with no apparent periodicity. Eighteen Salmonella serotypes caused clinical salmonellosis in horses, but 84% of the cases and 90% of the deaths were caused by 5 serotypes: Salmonella typhimurium, S typhimurium var copenhagen, S anatum, S kottbus, and S saint-paul. Overall, the case fatality rate was 44.9%. Excluding mixed infections, horses infected with S typhimurium and S typhimurium var copenhagen, had a significantly higher (P less than 0.001) case fatality rate (60.4%) than those infected with other Salmonella serotypes (32.3%).

Age Factors↗

PubMed1986

Risk factors for salmonellosis in hospitalized horses.

A case-control study to identify risk factors associated with isolation of Salmonella was accomplished, using data from records of horses hospitalized in the period July 1971 through June 1982. Horses in which nasogastric tubes were passed were at 2.9 times greater risk of having Salmonella isolated, compared with horses that did not undergo this procedure. Horses treated with antibiotics parenterally were at 6.4 times greater risk, and those treated with antibiotics orally and parenterally were at 40.4 times greater risk of developing salmonellosis, compared with horses not receiving such treatment. Horses admitted because of colic were 4.2 times as likely to have Salmonella isolated as those admitted for other reasons. Breed, age, and type of surgery did not appear to be risk factors. The risk factors identified and the magnitude of their association with Salmonella isolation were similar to those observed in a preceding study.

Age Factors↗

PubMed1985

A field trial to assess the therapeutic and prophylactic effect of a foot rot vaccine in sheep.

An 18-week field trial was conducted on a sheep ranch to evaluate the therapeutic and prophylactic effect of a commercial foot rot vaccine. Two hundred sheep were included in the study, 100 with detectable foot rot lesions and 100 without. Approximately 50 sheep from each group were selected randomly and vaccinated twice against foot rot at a 6-week interval in the late spring 1984; the remaining sheep acted as nonvaccinated controls. Therapeutic effect of the vaccine was demonstrated by a cure rate of 53% in vaccinated, foot rot-affected sheep vs a cure rate of 19% in nonvaccinated, foot rot-affected sheep. Prophylactic effect of the vaccine was demonstrated by a foot rot prevalence at the end of the 18-week period of 9% for vaccinated sheep vs 53% for nonvaccinated sheep. Associations of foot rot lesions and vaccination with body condition were found to be significant, as was the association between foot rot lesions and mortality.

Animals↗

PubMed1984

Case-control study of risk factors associated with isolation of Salmonella saintpaul in hospitalized horses.

In an investigation of a 1981-1982 outbreak of nosocomial Salmonella saintpaul infection in hospitalized horses at the University of California Veterinary Medical Teaching Hospital in Davis, California, a case-control study was performed using data gathered from the records of 33 cases and 132 controls. Multiple logistic regression risk analysis was used to identify factors associated with isolation of the organism, controlling for the effects of other, possibly confounding variables. Horses receiving parenteral antibiotics were at 10.9 times greater risk of having S. saintpaul isolated than were horses not receiving parenteral antibiotics. Horses intubated with nasogastric tubes were 3.9 times more likely to have had the organism isolated from fecal specimens than horses not intubated, and horses with a presenting complaint of colic were at 2.2 times greater risk of isolation than horses with other presenting complaints.

Animals↗

PubMed1984

Bacteria isolated from lymph nodes of California slaughter swine.

Lymph nodes from 280 slaughter swine from 9 California ranches were examined for the presence of aerobic microflora. Genera of interest which were isolated (and percentage of animals from which they were isolated) included Salmonella (4.3%), beta-hemolytic streptococci (8.2%), Mycobacterium avium-complex (6.4%), Corynebacterium pyogenes (0.4%), and Aeromonas hydrophila (5.7%). Patterns of bacterial isolations from swine herds may be of assistance in predicting herd health problems.

Abattoirs↗

PubMed1984

Epidemiology of bovine brucellosis in the Mexicali Valley, Mexico: data gathering and survey results.

Data for path analysis on the epidemiology of bovine brucellosis were gathered from 184 premises in Mexicali Valley, Mexico, that had dairy cattle, swine, and/or goats. Each farmer manager or owner was interviewed, using a pretested set of questions, and the livestock on the premises were serotested for Brucella antibodies. The focus in gathering these data was to identify the characteristics of premises with seropositive cattle in comparison with characteristics of premises with no seropositive cattle.

Agglutination Tests↗

PubMed1984

Patterns of preweaning diarrhea in piglets on a central California ranch.

To determine risk factors for development of diarrhea in litters of preweaned piglets, data were analyzed from records of 4,397 litters of swine farrowed on a central California ranch 1978-1982. Sixty-four percent of litters were treated for diarrhea. Statistical analysis by multiple logistic regression showed that litters born to young sows (parity less than or equal to 2) were 1.7 times more likely to develop diarrhea before weaning than were litters born to older sows (parity greater than or equal to 3) and that litters born on one end of farrowing barns were 1.3 times more likely to develop diarrhea than were litters born in the other end. The association of diarrhea with other variables--dam breed, sire, gestation group, gestation length, size of litter, number of mummies, runts or stillbirths per litter, farrowing barn of birth or day of the week farrowed--was weak or nonexistent (P greater than 0.01).

Animals↗

PubMed1984

Diarrhea in nonhuman primates: a survey of primate colonies for incidence rates and clinical opinion.

Veterinary clinicians associated with 18 colonies of nonhuman primates were surveyed for their experience with diarrhea disease in colony animals for calendar year 1981. The 1981 diarrhea incidence rate, diarrhea-specific mortality rate and diarrhea case fatality rate for 13,385 monkeys were 10.6%, 1.2% and 11.1%, respectively. It was not possible to incriminate age or type of housing as risk factors for diarrhea, but some species seemed at greater risk than others. Erythrocebus patas monkeys had relatively high diarrhea incidence rates (18.8%) and the highest case fatality rate (48.4%) of all species surveyed. Squirrel monkeys (Saimiri sciureus) and baboons (Papio sp.) had low diarrhea incidence rates (2.1% and 3.2%, respectively). This opinion survey indicated a lack of uniformity among primate clinicians with respect to approaches to diagnosis and therapy of monkey diarrhea. The survey also suggested that many of the agents associated were perceived differently among primate clinicians, and that the roles of some agents are still poorly understood.

Age Factors↗

PubMed1983

Serologic survey of California wild hogs for antibodies against selected zoonotic disease agents.

Blood samples were collected from trapped or hunter-killed wild hogs (Sus scrofa) in 4 areas of California. Sera were tested for antibodies against 7 zoonotic disease agents. Antibodies against Brucella sp were detected in 21 (15%) of 136 samples. Antibodies against Coxiella burnetii were found in 50% of the collected samples (67 of 135 tested). Of the 135 wild hogs screened for pseudorabies virus, 4 (3%) were seropositive. Leptospira interrogans antibodies were discovered in 118 (87%) of the 136 samples tested. Of the 130 samples screened for antibodies against Mycobacterium avium complex, 111 (85%) were seropositive. Antibodies against Toxoplasma gondii were detected in 17 (13%) of 135 wild hogs. Antibodies against Yersinia pestis were found in 9 (15%) of 59 sera tested.

Animal Population Groups↗

PubMed1983

Enterobacteriaceae and Aeromonas hydrophila in Minnesota frogs and tadpoles (Rana pipiens).

In 222 Rana pipiens frogs and 34 tadpoles captured in and near Minnesota, Aeromonas hydrophila and 29 species of Enterobacteriaceae, including yersinia enterocolitica and Salmonella arizonae, were isolated from intestines. The prevalence of members of the family Enterobacteriaceae was lowest in frogs captured in early spring and highest in frogs captured in late summer.

Aeromonas↗

PubMed1981

Aeromonas hydrophila in wild-caught frogs and tadpoles (Rana pipiens) in Minnesota.

Frogs and tadpoles were captured at 14 sites in and near Minnesota during 1978-79 and nearly all appeared healthy. Aeromonas hydrophila was isolated from 94 of 294 (32%) juvenile and adult frogs and from 66 of 104 (63%) tadpoles. Of the isolates from frogs and tadpoles respectively, 68% and 47% were from the intestine only, 12% and 32% were from the intestine and the other sites, and 20% and 21% were from extraintestinal sites only. Isolations were more frequent from frogs collected in March-June than in August-November. Evidence was not found that disease due to Aeromonas hydrophila was a primary cause of declining Rana pipiens populations in Minnesota.

Aeromonas↗

PubMed1975

Infant mortality in Macaca mulatta: neonatal and post-neonatal mortality at the California Primate Research Center, 1968-1972. A retrospective study.

Seven hundred forty-two Macaca mulatta births were recorded at the California Primate Research Center, 1968-1972. The neonatal mortality rate (deaths smaller than or equal to 30 days of age) was 10.8%, and the post-neonatal mortality rate (deaths at 31-183 days) was 6.9%. The neonatal mortality rate was higher in outdoor group cages than in indoor individual cages (24.8 vs. 8.0%). The post-neonatal mortality rate was also higher outdoors than indoors (15.9 vs. 5.9%). Outdoor mortality showed apparent seasonal variation, while indoor mortality did not.

Age Factors↗

PubMedDate not supplied

Transmission of Pasteurella multocida on California turkey premises in 1988-89.

Restriction endonuclease analysis (REA) of whole-cell DNA was used to determine possible sources of Pasteurella multocida for each outbreak of fowl cholera occurring in turkey flocks in eight commercial poultry companies in California from October 1988 to September 1989. Over this period, 179 isolates of P. multocida were obtained from dead turkeys in 80 meat and breeder flocks on 43 premises. P. multocida was isolated from wildlife on five premises. Isolates were characterized by subspecies, serotype, presence of plasmid DNA, and REA type. In 52 (65%) flocks, all isolates of P. multocida had the same REA pattern as the M9 live vaccine strain following digestion of DNA with the restriction enzyme SmaI. Field strains of P. multocida were obtained from 27 (34%) flocks, and one flock (1%) yielded both M9 and a field strain of the organism. REA of field strains of P. multocida revealed 17 different SmaI REA types. Based on matching SmaI REA types, potential sources of P. multocida were identified for 15 of the 28 flocks infected with field strains of the organism, and transmission between turkey premises was a possibility in only seven flocks.

Animals↗

PubMedDate not supplied

Restriction endonuclease analysis of Pasteurella multocida isolates from three California turkey premises.

Three California turkey premises that had repeated outbreaks of fowl cholera were studied for periods of 2 to 4 years. Using biochemical, serologic, plasmid DNA, and restriction endonuclease analyses of isolates of Pasteurella multocida from turkeys and wildlife on the premises, strains of the organism were found to be enzootic on two of the premises. On the third, a variety of strains of P. multocida were isolated from fowl cholera outbreak flocks.

Animals↗

PubMedDate not supplied

Serologic associations between fowl cholera and other diseases.

As part of a case-control study designed to identify fowl cholera risk factors, 2087 blood samples were collected from 71 California meat-turkey flocks. Samples were tested for antibodies to three mycoplasmas and four viruses pathogenic for turkeys. Flocks that had antibodies to Newcastle disease virus and/or Mycoplasma meleagridis had an increased risk of having an outbreak of fowl cholera. This information should prove useful for fowl cholera control programs in meat turkeys.

Animals↗

PubMedDate not supplied

California National Animal Health Monitoring System for meat-turkey flocks, 1988-1989: diagnostic testing results.

Six hundred fourteen meat turkeys were submitted for necropsy from 24 California ranches as part of the National Animal Health Monitoring System (NAHMS). Enteritis was the most frequent pathologic diagnosis in birds 18 days old or younger and the second most frequent diagnosis in birds 19-70 days old. Hemorrhagic enteritis was the most frequent diagnosis in birds aged 19-70 days. Tibial dyschondroplasia, bronchopneumonia, and ascaridiasis were ranked one through three in frequency of diagnoses in birds over 70 days of age. Salmonella was isolated from 71% of flocks tested, and Mycoplasma meleagridis was isolated from 33% of tested flocks over 70 days of age. Antibodies to several disease agents were detected, including hemorrhagic enteritis (100% of flocks over 70 days old) and Newcastle disease (63% of flocks over 70 days old).

Animals↗

PubMedDate not supplied

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. synoviae, M. meleagridis, Salmonella pullorum, Newcastle disease virus, avian encephalomyelitis virus, Bordetella avium, hemorrhagic enteritis virus, infectious bronchitis virus, and infectious bursal disease virus in 367 blood samples from 32 backyard premises. Twenty-two owners of backyard premises said they restricted visitor contact with their birds, and two required visitors to wear rubber boots and use boot disinfectant. Owners of seven premises used biologics and/or pharmaceutics for disease prevention. One family member worked on a commercial turkey ranch, but no other contact between owners, relatives, or employees and commercial poultry was reported.

Animals↗

PubMedDate not supplied

Homogeneity of characteristics of Pasteurella multocida isolated from turkeys and wildlife in California, 1985-88.

Five hundred twenty isolates of Pasteurella multocida, collected in California from September 1985 to November 1988, were characterized in the laboratory. Characteristics examined included serotype, capsular type, biotype (subspecies), and possession of plasmid DNA. Three hundred thirty-three isolates recovered from turkeys dying from fowl cholera, 88 isolates from liver turkeys in flocks with fowl cholera outbreaks in the recent past, and 99 isolates from wildlife captured on fowl cholera-outbreak and non-outbreak turkey premises were studied in this manner. Characteristics were fairly homogeneous among isolates, especially those obtained from turkeys. The majority of isolates were serotype 3,4, capsular type A, subspecies multocida, and lacked plasmid DNA. Common serotypes of isolates from turkeys and wildlife sampled on the same premises were noted in eight of 13 cases examined.

Animals↗