Johne's

Question 1

Causative agent

Answer 1

Mycobacterium avium ssp. paratuberculosis (nickname Map)

Question 2

Losses due to paratuberculosis?

Answer 2

“tip of the iceberg”

• Hidden losses occur due to silent infections (25-50%) and subclinical carriers (5-35%)
• visible losses = clinical dz (1-5%) and death (1%)

Question 3

Subclinical animals cause economic losses such as ….

Answer 3

decreased:
- milk production, feed efficiency,

increased: susceptibility, calving interval

Question 4

at what age are most animals infected?

Answer 4

younger>older

susceptibility decreases as animal ages

Question 5

sources of infection/ transmission routes?

Answer 5

fecal oral
colostrum, milk
transplacental

Question 6

for every clinical case you see, about ____% of the herd in likely infected

Answer 6

15-20%

Question 7

Typical age range of clinical animals?

Answer 7

2-6 years.

almost never see it in younger than 2 yr.

Question 8

Clinical signs

Answer 8

• pipestream diarrhea (may be waxing and waning at first, then become consistent)
• gradual weight loss, despite increased appetite
• lethargy