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.
Objective—To evaluate WBC concentration, plasma
fibrinogen concentration, and an agar gel immunodiffusion
(AGID) test for early identification of Rhodococcus
Animals—162 foals from a farm with enzootic R equi
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
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)
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
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
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.
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.
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.
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.
Objective—To estimate prevalence of and identify
risk factors for fecal Salmonella shedding among hospitalized
horses with signs of gastrointestinal tract
Animals—465 hospitalized horses with gastrointestinal
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)