Calf diarrhea is a commonly reported disease in young animals, and still a major cause of productivity and economic loss to cattle producers worldwide. In the report of the 2007 National Animal Health Monitoring System for U.S. dairy, half of the deaths among unweaned calves was attributed to diarrhea. Multiple pathogens are known or postulated to cause or contribute to calf diarrhea development. Other factors including both the environment and management practices influence disease severity or outcomes. The multifactorial nature of calf diarrhea makes this disease hard to control effectively in modern cow-calf operations. The purpose of this review is to provide a better understanding of a) the ecology and pathogenesis of well-known and potential bovine enteric pathogens implicated in calf diarrhea, b) describe diagnostic tests used to detect various enteric pathogens along with their pros and cons, and c) propose improved intervention strategies for treating calf diarrhea.
Animals ; Cattle ; *Cattle Diseases/diagnosis/drug therapy/microbiology/prevention & control ; Diarrhea/diagnosis/microbiology/prevention & control/*veterinary

Methods such as real time (RT)-PCR have not been developed for the rapid detection and diagnosis of Dermatophilus (D.) congolensis infection. In the present study, a D. congolensis-specific SYBR Green RT-PCR assay was evaluated. The detection limit of the RT-PCR assay was 1 pg of DNA per PCR reaction. No cross-reaction with nucleic acids extracted from Pseudomonas aeruginosa, Mycobacterium tuberculosis, Staphylococcus aureus, or Austwickia chelonae was observed. Finally, the RT-PCR assay was used to evaluate clinical samples collected from naturally infected animals with D. congolensis. The results showed that this assay is a fast and reliable method for diagnosing dermatophilosis.
Actinomycetales/*isolation & purification ; Actinomycetales Infections/diagnosis/microbiology/*veterinary ; Animals ; Cattle ; Cattle Diseases/*diagnosis/microbiology ; Fluorescent Dyes/*diagnostic use ; Horse Diseases/*diagnosis/microbiology ; Horses ; Limit of Detection ; Real-Time Polymerase Chain Reaction/*methods/veterinary ; Reproducibility of Results ; Sheep ; Sheep Diseases/*diagnosis/microbiology

Human brucellosis has a broad spectrum of clinical manifestations, which includes endocarditis, a focal complication that is uncommon yet responsible for the majority of associated deaths. The most successful treatment outcomes of Brucella endocarditis have been reported with usage of both antimicrobial agents and surgery. However, there are few reports on the treatment of Brucella endocarditis using antibiotics only. We report the first case in Korea of Brucella endocarditis with aortic valve vegetations and an accompanying splenic abscess, which were treated successfully with antibiotic therapy alone.
Abscess/*microbiology ; Animals ; Aortic Valve/microbiology ; *Brucella abortus ; Brucellosis/*diagnosis ; Cattle ; Dairying ; Endocarditis/*microbiology ; Humans ; Korea ; Male ; Middle Aged ; Occupational Diseases/*microbiology ; Spleen/microbiology ; Zoonoses

Mycobacterium (M.) bovis, a bacterium in the M. tuberculosis complex, is a causative agent of bovine tuberculosis, a contagious disease of animals. Mycobacterial culture is the gold standard for diagnosing bovine tuberculosis, but this technique is laborious and time-consuming. In the present study, performance of the SD Bioline TB Ag MPT4 Rapid test, an immunochromatographic assay, was evaluated using reference bacterial strains and M. bovis field isolates collected from animals. The SD MPT64 Rapid test produced positive results for 95.5% (63/66) of the M. bovis isolates from cattle and 97.9% (46/47) of the isolates from deer. Additionally, the test had a sensitivity of 96.5% (95% CI, 91.2-99.0), specificity of 100% (95% CI, 96.7-100.0), positive predictive value of 100% (95% CI, 96.7-100.0), and negative predictive value of 92.9% (95% CI, 82.7-98.0) for M. bovis isolates. In conclusion, the SD MPT64 Rapid test is simple to use and may be useful for quickly confirming the presence of M. bovis in animals.
Animals ; Cattle ; Cattle Diseases/*diagnosis/microbiology ; *Deer ; Immunochromatography/methods/*veterinary ; Mycobacterium bovis/classification/*isolation & purification ; Sensitivity and Specificity ; Tuberculosis/diagnosis/microbiology/*veterinary

A not pregnant 4-year-old Jersey cow was presented with the sudden appearance of respiratory noise, nasal discharge and moderate respiratory difficulty. Upon physical examination a snoring-like noise, extended head and neck position, exaggerated abdominal effort, bilateral nasal discharge and left prescapular lymph node enlargement were noted. Sub-occlusion of the initial portion of the respiratory tract was suspected. Radiographic and endoscopic examinations revealed a pedunculate mass on the dorsal aspect of the rhinopharynx, which was removed with endoscopically assisted electrosurgery. Histologic examination revealed a chronic pyogranulomatous inflammation with eosinophilic club-like bodies surrounding small colonies of rod-shaped bacteria. Results of histochemical staining were consistent with Actinobacillus-like bacteria and a diagnosis of respiratory actinobacillosis was reached. Surgery and antibiotic therapy were resolutive, as demonstated by an endoscopic check at the second month after surgery, even without the association of the traditional iodine cure, which is regarded as the treatment of choice for actinobacillosis.
Actinobacillosis/*diagnosis/drug therapy/microbiology/surgery ; Actinobacillus/physiology ; Animals ; Cattle ; Cattle Diseases/*diagnosis/drug therapy/pathology/surgery ; Female ; Respiratory Tract Infections/drug therapy/pathology/surgery/*veterinary ; Treatment Outcome

PCR is a highly accurate technique for confirming the presence of Mycobacterium avium subsp. paratuberculosis (Map) in broth culture. In this study, a simple, efficient, and low-cost method of harvesting DNA from Map cultured in liquid medium was developed. The proposed protocol (Universidad Austral de Chile [UACH]) was evaluated by comparing its performance to that of two traditional techniques (a QIAamp DNA Stool Mini Kit and cethyltrimethylammonium bromide [CTAB] method). The results were statistically assessed by agreement analysis for which differences in the number of cycles to positive (CP) were compared by Student's t-test for paired samples and regression analysis. Twelve out of 104 fecal pools cultured were positive. The final PCR results for 11 samples analyzed with the QIAamp and UACH methods or ones examined with the QIAamp and CTAB methods were in agreement. Complete (100%) agreement was observed between data from the CTAB and UACH methods. CP values for the UACH and CTAB techniques were not significantly different, while the UACH method yielded significantly lower CP values compared to the QIAamp kit. The proposed extraction method combines reliability and efficiency with simplicity and lower cost.
Animals ; Bacteriological Techniques/economics/*veterinary ; Cattle ; Cattle Diseases/diagnosis/*microbiology ; DNA, Bacterial/chemistry/genetics ; Female ; Mycobacterium avium subsp. paratuberculosis/*genetics ; Paratuberculosis/diagnosis/*microbiology ; Real-Time Polymerase Chain Reaction/veterinary ; Reproducibility of Results