Step 1: Understanding the Concept:
The genus Clostridium comprises Gram-positive, anaerobic, spore-forming, rod-shaped bacteria.
Different species produce distinct toxins that cause specific clinical diseases in livestock.
Identifying the precise association between clostridial species and their veterinary clinical presentations is essential for diagnosis and control.
Detailed Explanation:
Let us analyze the etiologies of the listed diseases:
- A. Lamb dysentery: Caused by Clostridium perfringens Type B. It is an acute, highly fatal disease of newborn lambs characterized by hemorrhagic enteritis and toxemia.
- B. Black leg (Blackleg): Caused by Clostridium chauvoei. It is an acute infectious disease of cattle and sheep characterized by necrotizing myositis and gaseous edema in large muscle masses.
- C. Braxy: Caused by Clostridium septicum. It is characterized by acute, hemorrhagic abomasitis in sheep, associated with the ingestion of frozen forage.
- D. Enterotoxemia: Primarily caused by Clostridium perfringens Type D (pulpy kidney disease) and Type C. It involves the absorption of potent enterotoxins from the intestine, leading to systemic vascular damage and encephalomalacia.
Based on this analysis, Clostridium perfringens is the causative agent of Lamb dysentery (A) and Enterotoxemia (D).
Step 2: Final Answer:
The correct combination is A and D only, which corresponds to Option (B).