Search Results
You are looking at 1 - 7 of 7 items for
- Author or Editor: Patrick L. McDonough x
- Refine by Access: All Content x
Abstract
Objective—To evaluate serum titers obtained by use of the microscopic agglutination test (ie, MAT titers) to Leptospira interrogans serovar pomona and autumnalis and Leptospira kirschneri serovar grippotyphosa in dogs given a commercial vaccine against serovars pomona and grippotyphosa.
Animals—Forty 12-week-old puppies and 20 mature Beagles.
Procedure—Puppies received a commercial vaccine against serovars pomona and grippotyphosa at 12 weeks of age, then received a booster vaccine and 3 weeks later; mature dogs received the vaccine once. Serum MAT titers to serovars pomona, autumnalis, and grippotyphosa were measured before vaccination and at 2, 4, 6, 10, and 16 weeks after the first or only vaccination.
Results—Of the 40 puppies vaccinated, 40, 0, and 40 developed MAT titers of > 100 after vaccination to serovars pomona, grippotyphosa, and autumnalis, respectively. Microscopic agglutination test titers to serovar autumnalis were higher than MAT titers to serovars pomona and grippotyphosa and persisted in some dogs for 16 weeks (6 weeks longer than for titers to serovar pomona). Of the 20 mature dogs, 13, 5, and 20 developed MAT titers of > 100 at 2 weeks to serovars pomona, grippotyphosa, and autumnalis, respectively. Titers to serovar pomona were higher and persisted in some dogs beyond 16 weeks after vaccination, compared with titers to serovars pomona and grippotyphosa, which persisted for 10 and 6 weeks, respectively.
Conclusions and Clinical Relevance—Subunit vaccines against serovars pomona and grippotyphosa induce MAT titers not only to homologous antigens but also to serovar autumnalis, which could lead to a misdiagnosis of leptospirosis caused by serovar autumnalis. (Am J Vet Res 2005;66:1780–1784)
Abstract
Objective—To estimate the prevalence of fecal shedding of Salmonella spp among bovine patients at a veterinary teaching hospital, to identify risk factors for fecal shedding of Salmonella organisms, and to characterize the serotypes.
Design—Retrospective cohort study.
Sample Population—5,398 hospitalized cattle.
Procedures—Data were collected for all cattle admitted during an 11-year period. Fecal shedding of Salmonella spp was determined by means of standard bacteriologic culture. Multivariable logistic regression models were used to identify risk factors for shedding of Salmonella spp among patients.
Results—The prevalence of Salmonella shedding among clinical suspects was 6.5% (50/768), whereas that among nonsuspects tested through routine surveillance was 2.5% (50/2,020). Among clinical suspect calves, fecal shedding of Salmonella spp was more likely for those admitted in the fall (odds ratio [OR], 5.9), those with septicemia (OR, 3.3), or those with an umbilical hernia (OR, 8.6). Among clinical suspect adult cattle, those with enteritis (OR, 9.9) or metritis (OR, 5.2) were more likely to be shedding Salmonella spp. Among nonsuspect cattle, none of the variables were significant predictors of shedding status. Twenty-one serotypes were detected during the study period, with the most common being Salmonella enterica serotypes Typhimurium (33%), Newport (23%), and Agona (12%).
Conclusions and Clinical Relevance—Seasonal and disease risk factors for fecal shedding of Salmonella spp were evident among clinical suspect cattle admitted to a veterinary teaching hospital. In contrast, lack of significant associations among nonsuspect cattle would suggest that targeted screening within this population is not warranted.
Abstract
Objective
To determine and quantify risk factors associated with exposure of horses to the following serovars of Leptospira interrogans: pomona, autumnalis, and bratislava.
Animals
2,551 horses were randomly selected from a target population during the period of May 1991 to August 1993.
Procedures
Blood was collected from the horses and tested for antibodies to serovars, using the microscopic agglutination test. A titer ≥ 1:100 indicated seropositivity. Information was collected on each horse, its environment, and each farm's management practices. Logistic regression analysis was used to develop a multidimensional indexing system for indices of exposure and to identify factors significantly associated with the risk of seropositivity. These indices were: 1) rodent exposure; 2) wildlife exposure; 3) soil and water; and 4) management.
Results
Rodent exposure index value was associated with the risk of exposure to all 3 serovars. Management index value was positively associated with the risk of exposure to serovars pomona and bratislava, but not with risk of exposure to serovar autumnalis. Soil and water index value had a positive association with risk of exposure to serovars pomona and autumnalis, but not to serovar bratislava. The wildlife index value and the population density of horses turned out together were associated with the risk of exposure to serovar autumnalis. Age of horse in years was associated nonlinearly (years2) and linearly (years) with the risk of exposure to serovars autumnalis and bratislava, and only linearly with the risk of exposure to serovar pomona.
Conclusion
Risk of seropositivity to the 3 serovars of L interrogans varies according to age, management practices, population density of horses turned out together, and the values of the rodent exposure, wildlife exposure, and soil and water indices. (Am J Vet Res 1997;58:1097–1103)
Abstract
Objective—To elucidate the ecology of Listeria monocytogenes on dairy cattle farms by determining the prevalence of the organism in various samples.
Sample Population—Dairy cattle operations in central New York State.
Procedures—A repeated cross-sectional study design was used. Various samples were obtained from cattle (feces, composite udder milk, and udders), their environment (silage, feed bunks, water troughs, and floor bedding), inline milk filters, and bulk tank milk from 50 dairy farms. Samples were tested for L monocytogenes by use of a PCR assay with 2 steps of bacterial enrichment. Data were analyzed with mixed-effect logistic regression to control for the potential clustering of L monocytogenes on particular farms.
Results—L monocytogenes was detected in composite milk, udder swab samples, and fecal samples at prevalences of 13%, 19%, and 43%, respectively. There was no significant clustering of the pathogen by farm. Listeria monocytogenes was more common in samples obtained from cattle and the environment during winter and summer versus the fall. The prevalence of L monocytogenes was twice as high in samples obtained from feed bunks, water troughs, and bedding, compared with that in samples obtained from silage (65%, 66%, 55%, and 30%, respectively).
Conclusions and Clinical Relevance—L monocytogenes was more prevalent in samples obtained from dairy cattle and their environment than in milk samples. Strategies to control the pathogen in dairy operations should focus on cow hygiene and sanitary milk harvesting on the farm.
Abstract
Objective
To evaluate a [13C]urea breath and blood test (UBBT) for detection of gastric infections with Helicobacter spp in dogs.
Animals
8 Beagles with, and 3 Beagles without, gastric Helicobacter spp infection.
Procedure
The UBBT was evaluated in dogs of known infection status before and after treatment with amoxicillin, metronidazole, and famotidine (AMF). A standard dose of [13C]urea (4 mg/kg of body weight) was given, and breath and blood samples were obtained at 0, 20, 40, and 60 minutes after administration. Effect of AMF treatment on breath and blood 13CO2 values, gastric urease activity (GUA), and gastric spiral organisms (GSO) was evaluated 3 to 4 and 28 to 29 days after 14 days of AMF treatment.
Results
Breath and blood 13CO2 values were higher in infected dogs than uninfected dogs. Endogenous 13CO2 production was minimal. Breath and blood 13CO2 values varied by 10 and 13%, respectively, between test periods. There was a correlation (R 2 = 0.985) between breath and blood 13CO2 values. In 6 of 8 infected dogs, these values were decreased 3 days after completion of AMF administration and biopsy specimens lacked GSO and GUA. For these 6 dogs, breath and blood 13CO2 values were variable 28 days after completion of AMF treatment, and were associated with recurrence of GSO in 6 dogs and GUA in 4 dogs.
Conclusions and Clinical Relevance
Results of this study indicate that UBBT may provide a noninvasive procedure for detection of gastric infections with Helicobacter spp in dogs. Treatment with amoxicillin, metronidazole, and famotidine may not be effective in eradicating gastric infections with Helicobacter spp in dogs. (Am J Vet Res 1998;59:1364–1369)
Summary
Prevalence of intraoperative contamination of the eyelids, conjunctival sac, and aqueous humor of 50 canine eyes that underwent elective cataract surgery was determined, and the short-term outcomes for contaminated and noncontaminated eyes were compared by scoring media clarity, pupil size and shape, and behavioral evidence of vision during the initial 30-day postoperative period. Results of bacteriologic culture of anterior chamber samples were positive for 12 of the 50 (24%) eyes, but anterior chamber contamination was unrelated to results of bacteriologic culture of eyelids or conjunctival sac swab samples. Eyes undergoing phacoemulsification were less likely to be contaminated than were eyes undergoing intra- or extracapsular extraction. Eyes undergoing intra- or extracapsular extraction and eyes with anterior chamber contamination had a greater likelihood of developing glaucoma postoperatively. We did not detect an association between intraocular contamination and the surgeon performing the operation, the need for postoperative administration of tissue plasminogen activator, or the presence or absence of diabetes mellitus. Also, we did not detect any differences in outcome between eyes with and without intraocular contamination. Despite intraoperative bacterial contamination of the anterior chamber, bacterial endophthalmitis did not develop in any of the eyes.
Abstract
Objective—To determine the duration of fecal shedding of and serologic response to Salmonella spp after natural infection in dairy calves and characterize Salmonella organisms recovered from these herds.
Design—Longitudinal study.
Animals—Calves from 2 dairy herds (A and B) in the northeast United States that were identified at the beginning of a Salmonella outbreak.
Procedures—Fecal samples were collected twice per week (herd A) or once per week (herd B); blood samples were collected for serologic testing once per week in both herds. Bacteriologic culture of fecal samples was performed, and Salmonella isolates were characterized by serotype, pulsed-field gel electrophoresis (PFGE) pattern, and antimicrobial resistance profile.
Results—All Salmonella isolates from herd A were serovar Typhimurium var Copenhagen, had the same PFGE pattern, and were resistant to at least 9 antimicrobials. All isolates from herd B were Salmonella Typhimurium, represented 2 PFGE patterns, and were susceptible to all antimicrobials evaluated. The estimated duration of fecal shedding was 14 days in herd A and 9 days in herd B. Few calves were seropositive for antibody against Salmonella lipopolysaccharide within the first week after birth (0 of 20 in herd A and 13 of 79 in herd B) or seroconverted (6 in herd A and 4 in herd B). Fecal shedding was more common in calves that seroconverted, but overall, there was not a strong association between seropositivity and fecal shedding of Salmonella organisms.
Conclusions and Clinical Relevance—Although the herds differed in serologic response and Salmonella subtype, the duration of fecal shedding among calves was similar between herds.
