Small Ruminant

Question 1

Corynebacterium pseudotuberculosis on culture

Answer 1

Gram positive coccoid rod; dry hockey puck colonies that can be easily moved on agar; facultative intracellular and facultative anaerobe

Question 2

How is CL spread?

Answer 2

Mainly environmental contamination –> inhaled, ingested or crosses the skin via break in epidermis

Question 3

Where are CL abscesses in goats?

Answer 3

Peripheral lymph node around head and body or chest most commonly affected

Question 4

Where are CL abscesses in sheep?

Answer 4

More diffuse abscess distribution, including lymph nodes of hind end

Question 5

T/F: No clinical signs with internal abscesses

Answer 5

False –> may have chronic weight loss or systemic disease

Question 6

Causes of false positive CL serology

Answer 6

Young animals (<6 mo) due to maternal antibodies; previously exposed and cleared infection; vaccinated animal

Question 7

Causes of false negative CL serology

Answer 7

Well encapsulated, heavily walled abscesses or early disease

Question 8

How to manage a new CL in a naive herd

Answer 8

Culled or isolated or at minimum isolated until abscesses developed, lanced, and healed

Question 9

Differential diagnosis for CL

Answer 9

Wattle cyst –> benign lymphatic drainage abnormalities occur at base of the wattle which is the fold of skin handing from goats

US will show non-encapsulated hypoechoic fluid chamber containing fluid consistent with lymphatic drainage; yellow transparent fluid with low cellularity (not similar to abscessed material)