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- Author or Editor: Jorge Hernandez x
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Abstract
Objective—To assess the efficacy of prophylactic hoof health examination and trimming during midlactation at reducing the incidence of lameness during late lactation in dairy cows.
Design—Randomized field trial.
Animals—333 Holstein cows.
Procedures—Cows without apparent lameness were randomly allocated into 1 of 2 groups approximately 204 days after calving. Cows allocated to the treatment group (n = 161) were examined on a tilt table for diagnosis and underwent hoof-trimming procedures, if needed, for treatment of hoof disorders or lesions. Cows in the control group (n = 172) were not examined. Cows were assigned a locomotion score weekly for 28 weeks after allocation to a group. The number of cows classified as lame during late lactation (approx 205 to 400 days after calving) was compared between groups to assess the efficacy of prophylactic examination and trimming.
Results—Incidence of lameness during late lactation was 24% in cows in the control group and 18% in cows in the treatment group.
Conclusions and Clinical Relevance—The 25% decrease in number of new cases of lameness in cows undergoing prophylactic hoof health examination and trimming during midlactation may be relevant for the well-being of dairy cows and should not represent a major economic burden to producers.
Abstract
Objective—To evaluate WBC concentration, plasma fibrinogen concentration, and an agar gel immunodiffusion (AGID) test for early identification of Rhodococcus equi-infected foals.
Design—Prospective study.
Animals—162 foals from a farm with enzootic R equi infection.
Procedure—Blood samples were obtained from each foal at 4-week intervals for measurement of WBC and plasma fibrinogen concentrations and at 2-week intervals for detection of anti-R equi antibody by an AGID assay. Diagnostic performance of WBC and fibrinogen concentrations was assessed by use of receiver operating characteristic curve analysis. For each assay, sensitivity, specificity, and predictive values were calculated at various cutoff points; bacteriologic culture of R equi from a tracheobronchial aspirate was used as the reference standard test.
Results—Diagnostic performance of WBC concentration was significantly higher than that of fibrinogen concentration. Sensitivity and specificity of measurement of WBC concentration at a cutoff of 13,000 cells/µL were 95.2 and 61.2%, respectively; at a cutoff of 15,000 cells/µL, sensitivity was 78.6% and specificity was 90.8%. When a positive test result was used as the cutoff, sensitivity of the AGID assay was 62.5% and specificity was 53.8%.
Conclusion and Clinical Relevance—Monitoring WBC concentration is a useful approach for early detection of infected foals on farms with a high prevalence of R equi pneumonia. In contrast, serologic surveillance by use of an AGID assay is of little benefit for that purpose. (J Am Vet Med Assoc 2003;222:775–781)
Abstract
Objective—To identify risk factors that may predispose California sea lions (Zalophus californianus) to development of cutaneous poxvirus nodules during hospitalization in a rehabilitation center.
Design—Retrospective case-control study.
Animals—90 California sea lions admitted to a rehabilitation center.
Procedure—Hospital records of 275 stranded California sea lions admitted to the rehabilitation center between January 1 and December 31, 2002, were reviewed. All California sea lions (n = 18) that developed ≥ 1 cutaneous poxvirus nodule during hospitalization were classified as cases. Seventy-two California sea lions that did not develop poxvirus lesions during hospitalization were randomly selected (control group). The frequencies of various exposure factors prior to admission, at admission, and during hospitalization for cases and control sea lions were compared by use of logistic regression.
Results—California sea lions that had previously been admitted to the rehabilitation center were 43 times as likely to develop poxvirus lesions as sea lions admitted for the first time; those with high band neutrophil counts (> 0.69 × 103 bands/μL) at admission were 20 times less likely to develop poxvirus lesions than sea lions with counts within reference limits.
Conclusions and Clinical Relevance—Results suggest that sea lions with a history of prior hospitalization or band neutrophil counts within reference limits at admission were more likely to develop poxvirus lesions during hospitalization. Sea lions with histories of hospitalization should be kept in quarantine and infection control measures implemented to help prevent disease transmission to attending personnel and other hospitalized animals. (J Am Vet Med Assoc 2005;227:467–473)
Abstract
Objective—To estimate prevalences of various presale radiographic findings and of presale arthroscopy in horses offered for sale at the 2006 Keeneland September yearling sale and to compare sales prices between yearlings with and without various presale radiographic findings or a history of arthroscopy.
Animals—397 Thoroughbred yearlings.
Design—Cross-sectional study.
Procedures—Presale radiographs and health records were examined to estimate prevalences of various radiographic findings and presale arthroscopy. Sales price records were used to compare sales prices between yearlings with and without various presale radiographic findings or a history of arthroscopy.
Results—In the forelimbs, the most common radiographic findings were vascular channels in the proximal sesamoid bones (23%), enthesophytes or osteophytes in the radiocarpal joint (22%), and osteochondritis lesions involving the sagittal ridge of the third metacarpal bone (20%). In the hind limbs, the most common radiographic findings were enthesophytes or osteophytes involving the proximal sesamoid bones (39%), abnormalities of the distodorsal aspect of the third metatarsal bone (36%), enthesophytes or osteophytes involving the distal intertarsal joint (27%), and osteochondritis lesions involving the stifle joint (8%). Thirteen percent of horses had a history of presale arthroscopy. Median sales price was significantly lower in horses with fragments of the proximal phalanx than in horses without. Median sales price was significantly higher in horses with a history of presale arthroscopy than in horses without.
Conclusions and Clinical Relevance—Results revealed significant associations between a diagnosis of fragments of the proximal phalanx, presale arthroscopy, and sales price in Thoroughbred yearlings.
Abstract
Objective—To examine the relationship between abdominal surgery and nosocomial Salmonella infections and the relationship between high caseload in combination with abdominal surgery and nosocomial Salmonella infections in hospitalized horses with signs of gastrointestinal tract disease.
Animals—140 horses.
Design—Case-control study.
Procedures—To accomplish the first objective, 1 to 4 control horses were matched with each nosocomial case horse on the basis of admission date of a primary case horse. The frequency of abdominal surgery and other investigated exposure factors were compared between nosocomial case horses and control horses. For the second objective, 4 control horses were matched with each nosocomial case horse on the basis of year of admission. The frequency of high caseload (≥ 26 inpatients), abdominal surgery, and other factors was compared between nosocomial case horses and control horses.
Results—The odds of nosocomial Salmonella infection were 8 times as high (odds ratio = 8.2; 95% confidence interval = 1.11, 60.24) in horses that underwent abdominal surgery, compared with the odds for horses that did not undergo surgery. High caseload alone or in combination with abdominal surgery was not associated with increased risk of nosocomial Salmonella infection.
Conclusions and Clinical Relevance—Abdominal surgery was identified as a risk factor for nosocomial Salmonella infections in horses. Horses that undergo abdominal surgery require enhanced infection control and preventative care. Risk of nosocomial Salmonella infections may be reduced by implementation of biosecurity measures (such as the use of plastic boots, gloves, and footbaths) immediately after surgery.
Abstract
Objective—To estimate prevalence of and identify risk factors for fecal Salmonella shedding among hospitalized horses with signs of gastrointestinal tract disease.
Design—Cross-sectional study.
Animals—465 hospitalized horses with gastrointestinal tract disease.
Procedure—Horses were classified as positive or negative for fecal Salmonella shedding during hospitalization by means of standard aerobic bacteriologic methods. The relationship between investigated exposure factors and fecal Salmonella shedding was examined by means of logistic regression.
Results—The overall prevalence of fecal Salmonella shedding was 13%. Salmonella serotype Newport was the most commonly isolated serotype (12/60 [20%]), followed by Anatum (8/60 [13%]), Java (13%), and Saint-paul (13%). Foals with gastrointestinal tract disease were 3.27 times as likely to be shedding Salmonella organisms as were adult horses with gastrointestinal tract disease. Adult horses that had been treated with antimicrobial drugs prior to hospitalization were 3.09 times as likely to be shedding Salmonella organisms as were adult horses that had not been treated with antimicrobial drugs prior to hospitalization. Adult horses that underwent abdominal surgery were 2.09 times as likely to be shedding Salmonella organisms as were adult horses that did not undergo abdominal surgery.
Conclusions and Clinical Relevance—Results suggest that a history of exposure to antimicrobial drugs prior to hospitalization and abdominal surgery during hospitalization were associated with Salmonella shedding in adult horses with gastrointestinal tract disease. Foals with gastrointestinal tract disease were more likely to shed Salmonella organisms than were adult horses with gastrointestinal tract disease. (J Am Vet Med Assoc 2004;225:275–281)
