Clostridial Diseases (Large Animal)

Question 1

Black leg is caused by

Answer 1

c. chauvoei

Question 2

malignant edema is caused by

Answer 2

any clostridial species, usually c. septicum, but in sheep, c. novyi type A

Question 3

redwater disease/bacillary hemoglobinuria is caused by

Answer 3

c. haemolyticum

Question 4

black disease is caused by

Answer 4

c. novyi type B

Question 5

tetanus is caused by

Answer 5

c. tetani

Question 6

botulism is caused by

Answer 6

c. botulinum

Question 7

enterotoxemia is caused by

Answer 7

c. perfringens types B,C,E

Question 8

overeating disease is caused by

Answer 8

c. perfringens type D

Question 9

jejunal hemorrhage and yellow lamb disease is caused by

Answer 9

c. perfringens type A

Question 10

You get a call from a farmer regarding a depressed, febrile beef cow with an acute swelling and crepitus over the right triceps muscle that has appeared over the past few hours. this cow was just recently transported to a new feedlot. On your way to the farm, the cow acutely dies. When you arrive you palpate the crepitus, and then perform a necropsy. you can see gas bubbles in the musculature and you smell a foul and somewhat sweet odor. diagnosis? what do you ask the producer?

Answer 10

blackleg (c chauvoei)

ask him about his vaccination program/protocol for clostridial diseases

Question 11

a 3yo quarter horse presents for a very acutely swollen and edematous neck. the horse is lethargic and has a high fever. when you palpate the neck you do not feel any crepitus, just edema. the horse was vaccinated recently, but other than that, there is no relevant history. what do you suspect? what treatment will you give?

Answer 11

malignant edema/c. septicum most likely

give penicillin

(for cows there’s a vaccine but idk about horses)

Question 12

you are called out to a cow farm. a few cows have acutely died, and others are lethargic, febrile, and seem to be urinating “pink” fluid. when you arrive, you check the cows mucus membranes and they are extremely pale. A sample of the “pink” urine shows hemoglobinuria. you elect to perform a necropsy on one of the dead cows. you find a focal area of necrosis in the liver, and the blood of the cow seems to be very thin and watery. diagnosis and treatment? how will you explain this to the producer?

Answer 12

bacillary hemoglobinuria (c. haemolyticum)

penicillin & anti toxin if available

prevention: vaccinate and avoid liver flukes! (fasciola hepatica, they migrate through the liver and create anaerobic necrotic tissue for the bacteria to replicate in)

Question 13

a sheep has acutely died and you go out to perform a necropsy. the producer says the sheep seemed totally normal last night and was found dead this morning. You find focal liver necrosis that appears black, and very pale mucus membranes. the carcass also gives off a very foul odor. diagnosis?

Answer 13

Black disease (sheep version of bacillary hemoglobinuria) caused by c novi type B

prevention: vaccination

Question 14

a horse presents after being castrated 2 days ago with a sawhorse stance and hypersensitivity to sounds and movement. he has only been like this for a few hours and is starting to appear more stiff in the legs with time. ddx? tx?

Answer 14

tetanus

penicillin + anti toxin

prevention: vaccine

Question 15

you are called out to a farm where multiple cattle have acutely died. the farmer did his own necropsy and sent you photos last night but you didn’t see anything abnormal, so you elect to go to the farm in the morning to check it out. When you get there the producer says some of the cows looked like they were “twitching and shaking” before they were found dead a few hours later. When you examine one of the dead cows, you find the tongue hanging out of the mouth, the pupils are quite dilated, and the 3rd eyelid is prolapsed. what is the next thing you should investigate in this herd?

Answer 15

likely botulism so need to investigate the food source, especially if many animals are affected.

prevention: vaccination

Question 16

a 5 day old calf presents for bloody diarrhea, weakness, fever, and convulsions. It acutely dies as you examine it and you perform a necropsy. you find red/purple fluid filled small intestine. ddx?

Answer 16

enterotoxemia (c perfringens type B,C,E)

vaccinate to prevent

Question 17

on necropsy of an acutely dead sheep you see very dark pulpy kidneys. the producer told you that his sheep recently switched to a very rich and grain heavy feed in order for them to gain weight and grow. ddx?

Answer 17

over eating disease caused by c. perfringens type D

Question 18

a dairy cow presents for bloody feces, tachycardia, and depression. what clostridial disease is this?

Answer 18

c. perfringens type A causing jejunal hemorrhage syndrome