Clostridia Diseases

Question 1

For blackleg:

1. Name the aetiological agent that is responsible
2. Describe the pathogenesis of this etiologic agent
3. What are the clinical signs?
4. How it is diagnosed?
5. How is it treated?

Answer 1

1. Cl. chavoei
2. Spores are ingested → cross the GI barrier into the bloodstream → multiply in aerobic environments (particularly damaged tissue - bruising) - risk factors include transport, handling, injection of any other activity
3. Crepitus and gas bubbles
4. Foul, sweet odour that resembles rancid butter
5. Penicillin + 7-way vaccination

Question 2

What is the main cause of malignant oedema in sheep?

Answer 2

C. novyi type A (they have a big head - the condition is often called bighead)

Question 3

For malignant oedema:

1. What is the cause?
2. What is the route of entry?
3. How is a diagnosis made?
4. How is it treated?

Answer 3

1. Any of the clostridia vaccines
2. Source is open wound: injury, castration, difficulty parturition
3. Swelling w/out gas accumulation
4. Treatment: penicillin + 7 way clostridium vaccine

Question 4

For Red water Disease (Bacillary haemoglobinuria):

1. State the cause
2. Describe the pathophysiology briefly
3. What are the clinical signs?
4. What findings are seen post-mortem?
5. How is treatment + control implemented?

Answer 4

1. Clostridium haemolyticum
2. Entry by wound → bacteria lodge in liver → damage occurs due to liver fluke → toxin released as a result of RBC lysis
3. Haemoglobinuria (red cell lysis) + anaemia
4. Large necrotic liver
5. Penicillin + tetracycline + liver fluke control

Question 5

What is the cause of blacks disease (infectious necrotic hepatitis)?

Answer 5

• Clostridium novyi type B
• Fasciola hepatica suspected to play a role

Question 6

For tetanus:

1. State the source of infection
2. What are the clinical signs?
3. How is it treated and prevented?

Answer 6

1. Entry through any wound
2. Saw horse, stiff tail, prolapsed third eyelid, flared nostril, sensitivity to noise and movement
3. Tranquiliser, Ab’s, tetanus antitoxin

Question 7

For botulism:

1. What is the main type that horses ae typically exposed to?
2. What is the main source of infection?
3. What are the clinical signs?
4. How is it treated/prevented?

Answer 7

1. Horses are especially susceptible to the type B toxin
2. It is usually introduced through contaminated feed (dead cat/rabbit in silage or hay)
3. Starts with muscle tremors and fasciculations → ascending paralysis
4. Botulism antitoxin exists + vaccinate against

Question 8

For Clostridia enterotoxaemia:

1. State the main types of Clostridia that are implicated
2. State the animal age that is usually affected
3. What is seen on PM?
4. How is the disease typically prevented/treated?

Answer 8

1. Clostridium perfringens Type B, C and E
2. Animals <7 days of age
3. Reddened sections of fluid filled small intestines (‘purple gut’)
4. Vaccinate and administering of IV fluids

Question 9

For overeating/pulpy kidney disease:

1. State the cause and aetiological agent

Answer 9

1. Clostridium perfringens Type D - high grain ration/rich pasture

Question 10

What is the cause of jejunal haemorrhage syndrome and is there a vaccine available for it?

Answer 10

• Clostridium perfringens type A