Tetanus: Etiology and Pathogenesis

Where is Clostridium tetani typically found?

What type of environment does Clostridium tetani require to thrive?

Through what means is Clostridium tetani typically introduced into the tissues?

In which animals does tetanus often follow docking or castration?

Why may the point of entry of Clostridium tetani not be found?

What is a common initial presentation of black leg disease?

What is a characteristic feature of black leg disease?

Which of the following body parts can be affected in black leg disease?

What is the temperature of animals affected with black leg disease?

What is the prognosis of animals found dead without premonitory signs of black leg disease?

Etiology and Pathogenesis of Tetanus

Causative agent: Clostridium tetani, an anaerobic bacterium with terminal, spherical spores
Common sources: Found in soil, especially cultivated soil, and intestinal tracts
Mode of transmission: Introduced into tissues through wounds, particularly deep puncture wounds, that provide a suitable anaerobic environment
High-risk wounds: Deep puncture wounds, docking or castration wounds (especially in lambs and sometimes in other species)
Occult infection: Point of entry may not be found due to minor or healed wounds

Black Leg Clinical Signs

Few animals may be found dead without showing any previous signs of illness
Acute and severe lameness, often affecting the hind legs, is a common clinical sign
Marked depression is a prominent feature of the disease
Fever may be present, but in some cases, body temperature can be normal or subnormal

Lesion Characteristics

Characteristic edematous and crepitant swellings develop in various parts of the body
Swellings typically occur in the hip, shoulder, chest, back, neck, or elsewhere
Swellings are focal, hot, and painful

Rare Complications

In extremely rare cases, the tongue can be affected, leading to protrusion

This quiz covers the causes and development of tetanus, a disease caused by the anaerobic bacterium Clostridium tetani. Learn about the common sources, mode of transmission, and high-risk wounds.