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Biomedical subjects

D W Hird

Publications and source records attributed to D W Hird.

At least 55 records · Page 3Linked to original sources
PubMed1990

Patterns of uterine prolapse in dairy cows and prognosis after treatment.

A 12-month study was undertaken in a 9-veterinarian dairy practice to determine patterns of uterine prolapse and factors associated with posttreatment survival. Of 220,000 cows in herds visited by veterinarians from the practice, 200 (0.09%) developed prolapses mostly (155/169 with data) in the first 24 hours after calving. Most cows (130/200) had prolapses during fall and winter months, and assistance was required in 47 of 200 calvings that resulted in prolapses. Treatment of affected cows (n = 196) consisted of cleansing and replacement of the uterus, insertion of perivulvar retention sutures, local and systemic administration of antibiotics, and parenteral administration of dexamethasone and oxytocin. Calcium was administered to cows with milk fever (n = 117) and to multiparous cows without milk fever attended by veterinarian 9 (n = 8). Crude recovery rate after 2 weeks was 72.4%, but recovery was significantly better if the calf was born alive (P = 0.001), the cow was primiparous (P = 0.03), the cow did not have stage-3 milk fever (P = 0.003), or if the cow was attended by veterinarian 9 (P = 0.01). Time to treatment was not significantly associated with recovery, but affected cows were treated mostly (127/156) within 2 hours of occurrence of the prolapse. By multivariable analysis, presence of a liveborn calf, parity, and lack of stage-3 milk fever, but not attending veterinarian, were significant (P less than 0.05) prognostic indicators of 2-week survival.

Animals↗
PubMed1990

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. Most (78%) of the cost of disease events was attributable to death and culling losses. Veterinary services accounted for only $54,099 (4%) of total costs, 64% of which was used for disease prevention, compared with 36% for disease treatment. Udder disease was the most costly category of diseases reported at an average of $49.85/head at risk annually, followed by reproductive problems at $38.05. Through the use of sampling strategies less biased than those used in other surveys, the National Animal Health Monitoring System is designed to provide statistically-valid estimates of disease incidence and costs across broad geographic areas, potentially benefiting all those interested in the economics of livestock diseases in the United States.

Animals↗
PubMed1990

Clinical, pathologic, and microbiologic findings of foot abscess in neonatal pigs.

A longitudinal study was undertaken in a swine herd with an ever-present problem of foot abscess in suckling pigs reared on a woven-wire floor. Of 3,322 4-day-old pigs, 199 (6%) developed abscess lesions involving claws and accessory digits before weaning. Lesions were first detected in 4-day-old pigs; median and mean ages at onset were 10 and 11.3 days, respectively. At first detection, most pigs had only a single claw affected, but 39 pigs had at least 2 claws with abscesses. Hind limbs had more affected claws (140) than forelimbs (96). In the hind limbs, medial claws were most likely to have lesions, whereas the reverse was true for the forelimbs. Gross and microscopic examinations of affected claws indicated necrotic pododermatitis, with severe osteomyelitis, arthritis, and tenosynovitis. Bacteria isolated from foot abscess lesions included Actinomyces pyogenes, Staphylococcus spp, beta-hemolytic Streptococcus spp, Actinobacillus spp, Escherichia coli, Fusobacterium spp, Bacteroides spp, and Peptostreptococcus spp.

Abscess↗
PubMed1990

Characteristics of Pasteurella multocida isolated from waterfowl and associated avian species in California.

Characteristics of Pasteurella multocida isolated from tissues of dead waterfowl and associated avian species found at 23 sites located in northern and central California, from January 1986 through January 1988 are reported. Two hundred ninety five isolates of P. multocida were obtained from 23 avian species. Most of the isolates belonged to the subspecies P. multocida multocida (63%), followed by P. multocida gallicida (37%), and by P. multocida septica (less than 1%). There appeared to be a higher prevalence of P. multocida multocida in Ross' geese (Chen rossi) and Snow geese (Chen coeruleus). All of the isolates belonged to somatic serotype 1, possessed the A capsule type and were susceptible to the 8 antimicrobial agents tested. None contained plasmid DNA.

Animals↗
PubMed1990

A cross sectional survey for B virus antibody in a colony of group housed rhesus macaques.

A systematic sampling technique was used in combination with a highly sensitive and specific ELISA to provide unbiased age-specific prevalence estimates of B virus antibody in rhesus monkeys housed in three different outdoor breeding corrals. Among 146 sampled monkeys, 97% of animals 2.5 years and older were seropositive, while only 22% of younger animals were seropositive. Neither gender nor social dominance ranking were predictive of B virus antibody status. The strong age association was not inconsistent with hypothesized venereal transmission of B virus. Improvements in the epidemiologic understanding of B virus are necessary to assist efforts to eradicate this agent from breeding colonies of rhesus monkeys.

Age Factors↗
PubMed1990

Host determinants of pneumonia in slaughter weight swine.

A prospective cohort study was undertaken in a farrow-to-farrow swine herd to describe patterns of pneumonia, and to identify host risk factors associated with the extent of pneumonic lesions in 2 weight groups of slaughter swine. The risk of coughing and pneumonic lesions increased with increasing age of pigs within the herd (P less than 0.0001). The age-specific prevalence of pneumonic lesions was low (2.7%) in pigs less than 16 weeks old at slaughter, but increased rapidly when pigs were between 16 and 22 weeks old (8.6 to 67.9%). After 22 weeks, the prevalence remained relatively constant at about 80%. Associations between possible risk factors and pneumonia were investigated by use of multiple-regression models. Age at weaning (less than 24 days) and birth weight (less than 1 kg) exerted small, but significant (P less than 0.002), effects on the extent of pneumonic lesions in pigs slaughtered at 30 to 50 kg live weight. For pigs slaughtered at 90 to 110 kg, pneumonic lesions were more extensive (P = 0.007) in pigs sired by Yorkshire boars than pigs sired by non-Yorkshire sires (Duroc, Hampshire, Chester White, or American Spotted). Other host factor variables including weaning weight and clinical diseases (atrophic rhinitis, diarrhea, and arthritis) were not associated with pneumonia extent in either weight group. Higher pneumonia percentages were also associated with reduced growth rates in the grower/finisher phase. Pigs sired by Yorkshire boars grew significantly (P less than 0.0001) more slowly from entry into shed 2 (mean, 38 kg) until about the time of exit (mean, 92 kg) than pigs sired by other breeds (747 g/d and 795 g/d, respectively).

Age Factors↗
PubMed1989

Randomized efficacy trials of long-acting oxytetracycline in neonatal pigs.

Prophylactic efficacy of 100 mg of long-acting oxytetracycline (OTC) given IM to neonatal pigs within 12 hours of birth was evaluated in a swine herd. The herd had a history of increased neonatal mortality, diarrhea, foot abscess, and arthritis in nursing pigs. Two trials were conducted in which liters and individual pigs were the treatment groups of interest. In both trials, OTC treatment failed to reduce mortality, diarrhea, or arthritis or the need for subsequent antimicrobial therapy (P greater than 0.05). Preweaning weight gains were not increased (P greater than 0.05) in treated pigs. However, in the individual pig trial, foot abscess rates were significantly (P = 0.01) lower in treated pigs (3.7%) than in nontreated pigs (8%). Aerobic bacteria isolated from pigs with diarrhea, arthritis, or foot abscess had minimum inhibitory concentrations for OTC greater than or equal to 64 micrograms/ml or were classed as resistant on the basis of disk-diffusion tests.

Abscess↗
PubMed1989

Resistance to antimicrobial agents and prevalence of R plasmids in Pasteurella multocida from turkeys.

One hundred fifty-three isolates of Pasteurella multocida, representing the causative agent of 95% of all known outbreaks of fowl cholera occurring in California meat and breeder turkeys from August 1985 through February 1987, were examined for susceptibility to antimicrobial agents. Of the 153 isolates, 6 were shown to be resistant to one or more antimicrobial agents. Of the six resistant isolates, five contained R plasmids. All but one of the R plasmids were small (6 to 7 megadaltons) and nonconjugative, encoding resistance to tetracycline or kanamycin, streptomycin, and sulfonamides; the other was large (70 megadaltons) and conjugative, transferring resistance to kanamycin, streptomycin, sulfonamides, and tetracycline to P. multocida and Escherichia coli. The three plasmids encoding resistance to tetracycline alone appeared identical.

Animals↗
PubMed1989

Use of an rRNA probe and restriction endonuclease analysis to fingerprint Pasteurella multocida isolated from turkeys and wildlife.

Twenty-five isolates of the bacterium Pasteurella multocida were characterized (fingerprinted) phenotypically and genotypically in order to compare the abilities of various techniques to differentiate strains for epidemiologic studies of fowl cholera. Isolates were obtained over a 16-month period from turkeys dying from fowl cholera (six outbreak flocks) and from wildlife captured on premises with a history of the disease. The characteristics compared included (i) serotype, (ii) subspecies, (iii) antibiogram, (iv) presence of plasmid DNA, (v) restriction endonuclease analysis patterns of whole-cell DNA, and (vi) ribotype. Ribotyping, a method of highlighting DNA restriction site heterogeneity by using an rRNA probe, worked well for differentiating the strains of P. multocida when the majority of the other techniques could not. Ribotyping results correlated directly with and confirmed results obtained from restriction endonuclease analysis. Ribotyping demonstrated the presence of up to three strains of P. multocida in one outbreak flock, recurrence of a single strain in five of the flocks over an 11-month period, and the presence of common strains in turkeys and wildlife on the premises.

Animals↗
PubMed1989

Neonatal survival in swine: effects of low birth weight and clinical disease.

Data were collected for 3,636 full-term pigs born in a commercial swine herd to determine the effects of birth weight and clinical disease on survival during the first 3 weeks of life. Logistic regression models were constructed for 7-day survival for all live-born pigs, and for 21-day survival for pigs surviving the first week of life. Estimates of birth weight and disease effects were adjusted simultaneously for other risk factors including litter size, parity, and within-litter variation in birth weight. The 7-day survival model indicated that survival odds improved significantly with increasing birth weight. Maximal survival, relative to pigs weighing less than 601 g at birth, was evident in pigs weighing greater than 2 kg at birth (odds ratio [OR] = 349). Diarrhea (OR = 2.7) and splayed limbs (splay leg; OR = 37.3) significantly (P less than 0.05) reduced 7-day survival. Models of 21-day survival indicated a smaller, but still significant, effect of birth weight on survival. Adjusted survival odds for pigs in the heaviest weight group (greater than 2 kg) were 20.1 times higher than pigs weighing less than 801 g. Diarrhea (OR = 2.7) and lameness (OR = 2.6, 2 limbs) significantly (P less than 0.05) decreased 21-day survival.

Animal Feed↗
PubMed1989

Environmental source of mycobacteriosis in a California swine herd.

Between July 1985 and April 1986, mycobacterial lymphadenitis was recorded in six of 2407 slaughter pigs from a commercial swine herd in which the majority of pigs were raised in confinement. Records showed that all six affected pigs had access to dirt-floored pens at least 81 days prior to slaughter. The mycobacteriosis lesion rate for pigs exposed to dirt pens was 9.4% while in nonexposed pigs the lesion rate was zero. The risk associated with movement of pigs from concrete floored pens to dirt pens was evaluated by a field trial. In the field trial, two litters (5 of 15 pigs) exposed to dirt pens at 12-24 days of age but none of nine nonexposed litters (39 pigs) developed lesions. Mycobacterium avium-complex bacteria were recovered from both exposed litters (9 of 15 pigs) but from none of nine nonexposed litters. Serovars of M. avium-complex isolated from trial pigs included 1, 4, 8, 9, the dual serovar 4/8, and an untypable serovar. Incense-cedar bark (Calocedrus decurrens) used as a flooring material in the pens was demonstrated to be a potential source of M. avium-complex serovar 9. The dual serovar 4/8 and an untypable M. avium-complex were isolated from the dirt-floored pens. No evidence of cross-transmission of M. avium-complex infection was detected. The sporadic pattern of mycobacteriosis observed in the herd probably resulted from infrequent exposure to a common environmental source.

Animals↗
PubMed1989

Humoral recognition of lipopolysaccharide core antigens of gram-negative bacteria in neonatal swine.

Serologic recognition of common lipopolysaccharide core antigens has been related to enhanced resistance to gram-negative bacterial disease in several species. Class-specific titers (IgG, IgM) were determined by direct ELISA, using intact Escherichia coli (J5) as a plate antigen. Serum samples were obtained from 224 neonatal swine between the ages of 36 and 60 hours. The mean (+/- SEM) log10 IgG titer against gram-negative core antigens was 1:1,713 +/- 0.4718 and the mean log10 IgM titer was 1:202 +/- 0.5644. The IgG titer was directly related with litter size, birth weight, and serum total IgG concentration; IgM titer was directly related with dam parity and serum total IgG concentration.

Animals↗
PubMed1988

Epidemic listeriosis associated with Mexican-style cheese.

In Los Angeles County, California, 142 cases of human listeriosis were reported from January 1 through August 15, 1985. Ninety-three cases (65.5 percent) occurred in pregnant women or their offspring, and 49 (34.5 percent) in nonpregnant adults. There were 48 deaths: 20 fetuses, 10 neonates, and 18 nonpregnant adults. Of the nonpregnant adults, 98 percent (48 of 49) had a known predisposing condition. Eighty-seven percent (81 of 93) of the maternal/neonatal cases were Hispanic. Of the Listeria monocytogenes isolates available for study, 82 percent (86 of 105) were serotype 4b, of which 63 of 86 (73 percent) were the same phage type. A case-control study implicated Mexican-style soft cheese (odds ratio, 5.5; 95 percent confidence interval, 1.2 to 24.8) as the vehicle of infection; a second case-control study showed an association with one brand (Brand A) of Mexican-style soft cheese (odds ratio, 8.5; 95 percent confidence interval, 2.4 to 26.2). Laboratory study confirmed the presence of L. monocytogenes serogroup 4b of the epidemic phage type in Brand A Mexican-style cheese. In mid-June, all Brand A cheese was recalled and the factory was closed. An investigation of the cheese plant suggested that the cheese was commonly contaminated with unpasteurized milk. We conclude that the epidemic of listeriosis was caused by ingestion of Brand A cheese contaminated by one phage type of L. monocytogenes serotype 4b.

Adult↗
PubMed1988

Patterns and determinants of rectal prolapse in a herd of pigs.

A prospective cohort study was designed to describe the patterns and to determine the factors associated with the risk of rectal prolapse in a commercial swine herd in California, USA. Thirty (1.0 per cent) of 2862 pigs prolapsed between 12 and 28 weeks of age with the peak incidence occurring in 14- to 16-week-old pigs. The overall prolapse rate was 9.1 cases per 100,000 days at risk. Prolapse rates were highest during the winter and autumn months. Other factors associated with an increased risk of prolapse were maleness (relative risk 2.3) birthweight less than 1000 g (relative risk 3.4) Yorkshire boar A (relative risk 2.8) and dams of litter number 1 (relative risk 14.9), 2 (relative risk 8.2) and 3 (relative risk 9.8). No evidence was found to support the hypothesis that diarrhoea and coughing are factors associated with a risk of prolapse.

Age Factors↗
PubMed1988

Prevalence of Giardia in the feces of pups.

Fecal specimens were collected from 117 healthy pups (79 privately owned pups and 38 pups from an animal shelter) and analyzed for Giardia. Giardia cysts or trophozoites were found in 35.9% of the dog feces.

Animals↗
PubMed1988

Financial impact of transmissible gastroenteritis in pigs.

The financial impact of an epizootic of transmissible gastroenteritis in pigs was evaluated in a California sow herd through estimating growth, feed, and profit functions. Two groups of pigs were studied: pigs born before and surviving the epizootic (epizootic [E] pigs), and pigs born after the epizootic (postepizootic [PE] pigs). Short-term profits were maximized at 165 days for both groups of pigs, ranging from $47.14 for female E pigs to $60.32 for male PE pigs. Accordingly, it was concluded that pigs surviving or born shortly after a transmissible gastroenteritis epizootic are profitable to raise, if raised under management conditions similar to those in the study herd.

Animal Feed↗
PubMed1988

Case-control study of risk factors associated with nosocomial Salmonella krefeld infection in dogs.

In a case-control study of risk factors associated with an episode of nosocomial Salmonella krefeld infection in dogs at the veterinary medical teaching hospital, data on 20 case dogs and 75 control dogs were obtained by review of hospital records. Univariate and multivariate statistical analyses were carried out for possible risk factors for infection to obtain odds of Salmonella krefeld isolation, given exposure to each risk factor of interest. Compared with control dogs, case dogs were 11.9 times more likely to have been fed rice, 7 times more likely to have had radiography done, 10.2 times more likely to have been a resident in ward 2, 5.6 times more likely to have been given antimicrobial agents orally, 11.3 times more likely to have been given antimicrobial agents parenterally, and 37.9 times more likely to have been given antimicrobial agents orally and parenterally (P less than 0.05).

Animals↗