Rhodococcus, Clostridium, Actinomyces, Dermatophilus

Question 1

C. novyi causes which disease in livestock?

Which tissue is affected?

Answer 1

Venous congestion or “black disease”

Liver and hepatic lymph

Question 2

How are are animals infected by members of the genus Clostridium?

Answer 2

By wound infection or ingestion of endospores

Question 3

What does C. difficile cause in companion animals?

Answer 3

Disruption of the normal intestinal microflora leading to diarrhea

Question 4

What other measures can be used to control Rhodococcus equi infections?

Answer 4

Dust control

Remove foals from contaminated grounds or pasture

Question 5

What disease patterns in large ruminants are caused by members of the genus Actinomyces?

Answer 5

Osteomyelitis (“lumpy jaw”

Epidermitis

Question 6

Which speices of Clostridium causes gas gangrene?

What else can it cause in companion animals?

Answer 6

C. perfringes

Enterotoxemia

Question 7

What disease patterns in pigs are caused by members of the genus Actinomyces?

Answer 7

Mastitis, pnuemonia, abortion, epidermitis

Question 8

How are exotoxins produced by members of the genus Clostridium classified?

Answer 8

Histotoxic or neurotoxic exotoxins

Question 9

What disease does Rhodococcus equi normally cause?

Answer 9

Foal pneumonia

Adult horses can also be affected

Question 10

What disease pattern does C. botulinum cause?

Answer 10

Flaccid paralysis

Question 11

C. chauvoei causes which disease in livestock?

Answer 11

myositits

“blackleg”

Question 12

How are Clostridium infections treated and controlled?

Answer 12

Antibiotics (penicillin or tetracycline)

Antitoxin (antisera or purified Ig)

Vaccination (cattle and horses)

Question 13

C. haemolyticium causes which disease in livestock?

Which tissue is affected?

Answer 13

hemoglobinuria or “red water”

Liver and hepatic lymph

Question 14

What disease patterns in horses are caused by members of the genus Actinomyces?

Answer 14

Bursitis (“poll evil” or “fistulous withers”)

Epidermitis

Question 15

What disease patterns in ruminants are caused by members of the genus Dermatophilus?

Answer 15

Rain scald, strawberry foot rot, lumpy wool

Question 16

What disease pattern does C. tetani cause?

Answer 16

Continuous to transitiory spastic (stiff) paralysis

Question 17

Which species should be annually vaccinated against histotoxic Clostridium?

How many species does the vaccine protect against?

Answer 17

Cattle. They should also be vaccinated before giving birth.

Seven

Question 18

Does an animal have to be exposed to either C. tetani or C. botulinum to develop disease?

Answer 18

No, they can be exposed to just the exotoxins in the environment

Question 19

What is the antibiotic of choice to treat Rhodococcus equi?

Which class of antibiotics should be avoided?

Answer 19

Erythromycin+rifampin

Avoid beta-lactams

Question 20

C. piliforme causes which disease in livestock?

Answer 20

“Tyzzer’s” liver necrosis

Question 21

What disease patterns in small ruminants are caused by members of the genus Actinomyces?

Answer 21

Epidermitis

Question 22

What general disease patterns are casued by histotoxic members of the genus Clostridium?

Answer 22

Enterotoxemia and septicemia

(can include gastritis, hemorrhagic enteritis, cerebral hemorrhage, etc.)

Question 23

How are Actinomyces and Dermatophilus infections treated and controlled?

Answer 23

Drain abcesses, topical/systemic iodine

Antibiotics

Provide shelter and grooming

Question 24

Is Rhodococcus equi normally found among a horse’s microbiota?

Answer 24

No. It normally lives in soil and horses can become infected when they inhale contaminated dust.

Question 25

Which antibiotics are commonly used to treat Actinomyces and Dermatophilus infections?

What is the first choice?

Answer 25

First choice- penicillin or ampicillin

Others- rifampin, macrolides, tetracycline

Question 26

What disease patterns in dogs and cats are caused by members of the genus Actinomyces?

Answer 26

Wound infection (associated with grass awns)

Epidermitis

Question 27

How is the morphology of Actinomyces described?

Answer 27

Branching, filamentous