Johne's

Question 1

What pathogen causes Johne’s?

Answer 1

Mycobacterium avium subspecies paratuberculosis

Question 2

What age animals are affected by Johne’s? What stimulates the virus to activate?

Answer 2

3+ years

Often after stress e.g. calving

Question 3

What are the clinical signs of Johne’s?

Answer 3

Profuse D+ with bubbles
Weight loss
Bottle jaw
BUT remain BAR

Question 4

What is the gold standard for diagnosing Johne’s?

Answer 4

Faecal, blood or milk culture

Slow!

Question 5

Apart from culture, how else can Johne’s be diagnosed?

Answer 5

Serology (ELISA) - poor at detecting infected, only detects infectious
PCR - expensive

Question 6

How can Johne’s be prevented/controlled?

Answer 6

Hygiene around calving time - snatching calves, feed artificial colostrum
Pasteurise milk
Test and cull
Reduce faecal contamination

Question 7

Is there a vaccination for Johne’s?

Answer 7

Yes - but only extends incubation!