Clinical presentation and diagnostics of cattle with suspected Johne’s disease

Baro Basora, Joan (2019) Clinical presentation and diagnostics of cattle with suspected Johne’s disease. MVM(R) thesis, University of Glasgow.

Abstract

Johne’s disease, caused by the bacteria Mycobacterium avium subsp. paratuberculosis (MAP), is a chronic, wasting condition of ruminants, which is characterized by the clinical signs of weight loss and diarrhoea. The economic losses associated with the disease in the cattle and sheep industry, worldwide spread and high prevalence make Johne’s disease an important disease to investigate. Additionally, MAP has been isolated from humans suffering of Crohn’s disease and zoonotic potential of MAP in humans is still under debate. Currently available diagnostic tests have impaired sensitivity, particularly in preclinical stages of disease and thus a prompt and effective identification of infected animals is difficult. The primary aim of this work was to analyse and describe the history, clinical presentation and diagnostic test results of cattle submitted to a veterinary teaching hospital that showed clinical signs consistent with Johne’s disease. The secondary aim was to compare diagnostic test results to the gold standard, faecal culture.
Fifty-nine out of the 192 cattle referred over 18 months met the inclusion criteria for the study, which was poor body condition or a history of weight loss and diarrhoea. A total of 52 females and seven males, comprising 34 beef and 25 dairy cattle were studied. All cattle had a full clinical examination, biochemistry blood analysis, Johne’s blood serology and faecal PCR and culture. They were inspected post-mortem and the ileo-caecal valve and proximal lymph node were examined histopathologically using a haematoxylin-eosin (H/E) and Ziehl-Neelsen (ZN) staining. Results from clinical examination, albumin and globulin serum concentrations, Johne’s serology, PCR, post-mortem examination and histopathology examination were compared to faecal culture results. Thus, this study reported all the clinical and diagnostic test results commercially available for Johne’s disease in cattle, such study was not reported before. Results showed inconsistent results between PCR and culture tests. However, both blood serology and H/E slide examination tests had a specificity of 100%.
This work should help inform clinicians on interpretation of Johne’s diagnostic testing in clinical cases and may have implications for Johne’s control programmes relying on the results from the diagnostic tests reported.

• Item Type: Thesis (MVM(R))
• Qualification Level: Masters
• Keywords: Johne's, paratuberculosis, cattle, ill thrift, diarrhoea, poor body condition, serology, PCR, culture, histology, ZN.
• Subjects: Q Science > QR Microbiology; R Medicine > RA Public aspects of medicine > RA0421 Public health. Hygiene. Preventive Medicine; S Agriculture > SF Animal culture > SF600 Veterinary Medicine
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Supervisor's Name: Ellis, Dr. Kathryn
• Date of Award: 2019
• Depositing User: Mr Joan Baro Basora
• Unique ID: glathesis:2019-71952
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 28 May 2019 16:11
• Last Modified: 23 May 2022 10:17
• Thesis DOI: 10.5525/gla.thesis.71952
• URI: https://theses.gla.ac.uk/id/eprint/71952