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- Author or Editor: Dale D. Hancock x
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Abstract
Objective—To determine patterns of mycoplasma shedding in the milk of dairy cows with intramammary mycoplasma infection.
Design—Prospective clinical trial.
Animals—10 Holstein cows with intramammary mycoplasma infection.
Procedure—Milk samples were collected from each cow daily for 28 days and plated on mycoplasma agar to evaluate shedding patterns. To determine whether enrichment improved recovery of organisms, some samples were also inoculated in mycoplasma enrichment medium and incubated for 4 days prior to plating. Somatic cell count (SCC) was determined in samples collected weekly.
Results—Mycoplasma organisms were not isolated from 81 of 280 (29%) composite milk samples, but > 106 colonies/mL were obtained from 151 (54%). Similarly, mycoplasma organisms were not isolated from 433 of 1,008 (43%) quarter milk samples, but > 106 colonies/mL were obtained from 392 (39%). For 71 of 104 (68%) samples, mycoplasma organisms were isolated both following direct plating and following enrichment; for 24 of 104 (23%), mycoplasma organisms were isolated only following enrichment; and for 9 of 104 (9%), mycoplasma organisms were isolated only after direct plating. There was a linear correlation between logarithm of the SCC and logarithm of the number of colony-forming units of mycoplasma per milliliter of milk for composite and quarter milk samples.
Conclusions and Clinical Relevance—Shedding of organisms was inconsistent in dairy cows with intramammary mycoplasma infection, increasing the risk of misdiagnosis if multiple milk samples are not tested. (J Am Vet Med Assoc 2003;223:1163–1166).
Abstract
Objective—To evaluate survival time of dogs with idiopathic Fanconi syndrome.
Design—Case series.
Animals—60 dogs with idiopathic Fanconi syndrome.
Procedure—Data were collected by means of questionnaires distributed to owners and veterinarians of dogs with idiopathic Fanconi syndrome and by examination of medical records when accessible. Questionnaires and records were reviewed for criteria used in diagnosis, treatments administered, survival time, and subjective owner perceptions regarding their dogs' general condition.
Results—58 of the dogs were Basenjis. Fifty-seven dogs (95%) were reportedly managed by use of a single therapeutic regimen. Median survival time after diagnosis of Fanconi syndrome was 5.25 years; median estimated lifespan was calculated to be between 11.3 and 12.1 years. Owners of 28 of 29 (97%) dogs still alive at the time of the study subjectively assessed their dogs' general condition as good to excellent. Seizures or other neurologic dysfunction was reported for 11 dogs.
Conclusions and Clinical Relevance—Results suggest that expected lifespan for dogs with idiopathic Fanconi syndrome was not substantially reduced, compared with expected lifespan for unaffected dogs, and that affected dogs generally had a good to excellent quality of life, as subjectively assessed by their owners. What effect the treatment regimen had on survival time or lifespan could not be determined, given the small number of dogs managed with other methods. The high percentage of dogs with neurologic abnormalities was a concern, but whether this was related to Fanconi syndrome or represented a breed-related predisposition to neurologic disease could not be determined. ( J Am Vet Med Assoc 2004;225:377–383)
Abstract
Objective—To evaluate the association between maintaining joint hospital and maternity pens and persistence of multi–drug-resistant (MDR) Salmonella enterica serovar Newport on 2 dairy farms.
Design—Observational study.
Sample Population—Feces and environmental samples from 2 dairy herds.
Procedure—Herds were monitored for fecal shedding of S enterica Newport after outbreaks of clinical disease. Fecal and environmental samples were collected approximately monthly from pens housing sick cows and calving cows and from pens containing lactating cows. Cattle shedding the organism were tested serially on subsequent visits to determine carrier status. One farm was resampled after initiation of interventional procedures, including separation of hospital and maternity pens. Isolates were characterized via serotyping, determination of antimicrobial resistance phenotype, detection of the CMY-2 gene, and DNA fingerprinting.
Results—The prevalence (32.4% and 33.3% on farms A and B, respectively) of isolating Salmonella from samples from joint hospital-maternity pens was significantly higher than the prevalence in samples from pens housing preparturient cows (0.8%, both farms) and postparturient cows on Farm B (8.8%). Multi–drug-resistant Salmonella Newport was isolated in high numbers from bedding material, feed refusals, lagoon slurry, and milk filters. One cow excreted the organism for 190 days. Interventional procedures yielded significant reductions in the prevalences of isolating the organism from fecal and environmental samples. Most isolates were of the C2 serogroup and were resistant to third-generation cephalosporins.
Conclusions and Clinical Relevance—Management practices may be effective at reducing the persistence of MDR Salmonella spp in dairy herds, thus mitigating animal and public health risk.
Abstract
Objective—To describe geographic, farm-type, and animal-type factors associated with multiple antimicrobial resistance (MAR) in fecal Escherichia coli isolates from cattle.
Design—Cross-sectional field study.
Sample Population—1,736 fecal samples from cattle on 38 farms in California, Oregon, and Washington.
Procedures—Fecal samples were collected from preweaned calves (2 to 4 weeks old) and cows that recently calved on dairy and beef cow-calf farms, preweaned calves on calf ranches, and 1-year-old steers on feedlots. One fecal E coli isolate per sample was isolated, and antimicrobial susceptibility was tested. Escherichia coli isolates were initially clustered by antimicrobial resistance patterns and categorized by number of antimicrobial resistances. A generalized estimating equations cumulative logistic regression model was used to identify factors associated with an increase in MAR in fecal E coli isolates from cattle.
Results—MAR was higher in E coli isolates from cattle in California, compared with those from cattle in Washington or Oregon. Multiple antimicrobial resistance was highest in E coli isolates from calves on calf ranches and progressively lower in isolates from feedlot steers, dairy cattle, and beef cattle. Multiple antimicrobial resistance was higher in E coli isolates from calves than from adult cattle, in E coli isolates from cattle of conventional farms than of organic farms, and in isolates from beef cattle in intensive dairy farm regions than from beef cattle distant from dairy farm regions.
Conclusions and Clinical Relevance—MAR in fecal E coli isolates from cattle was influenced by factors not directly associated with the use of antimicrobials, including geographic region, animal age, and purpose (beef vs dairy).
