Clostridial Diseases Flashcards
What causes blackleg? What animals are most commonly affected?
Clostridium chauvoei
mainly cattle between 6 months to 2 years of age + sheep due to a wound or postparturition
What is the transmission of blackleg like?
- endospores of C. chauvoei are ingested and cross the GI tract into the bloodstream
- endospores are deposited throughout the body or enter through a wound
- bacteria become activated and multiply in an anaerobic environment, particularly bruised or damaged muscle (most commonly occurring during transport, handling, injection, or rough activity)
What is the classic clinical sign indicative of blackleg? What else is commonly observed?
swelling with possible palpable crepitus from gas bubbles
- lameness
- fever
- depression
- anorexia
- rapid death without signs of illness, usually within 12-48 hours
How is blackleg diagnosed? What is seen postmortem?
presumptive diagnosis based on gaseous swelling in a young animal
infected area is black and necrotic with gas bubbles –> foul, sweet odor resembling rancid butte is commonly present
What treatment is recommended for cases of blackleg? What are 2 options of prevention?
Penicillin –> requires early identification and survivors may have permanent deformities
- immediately dispose carcasses without contaminating the environment
- 7-way bacterin vaccine: 2 doses at one month intervals
What are the contents of the 7-way clostridial bacterin vaccine?
- C. chauvoei
- C. septicum
- C. novyi A
- C. novyi B
- C. sordellii
- C. perfingens C
- C. perfringens D
What animals are affected by malignant edema? How does this disease develop?
cattle, sheep, goats, and horses of any age
an open wound is infected with the bacteria –> injury, castration, difficult parturition, fighting, etc.
What is bighead?
form of malignant edema in sheep caused by Clostridium novyi type A
What clinical signs are indicative of malignant edema?
- localized swelling and edema that may gravitate to dependent portions of the wound
- depression, anorexia, high fever
- death often occurs within 24-48 hours
How is malignant edema diagnosed?
postmortem = infected area is darkened with a foul odor, there is swelling WITHOUT gas accumulation
How is malignant edema treated? How is it prevented?
Penicillin –> requires early identification
- vaccination with 7-way bacterin vaccine
- clean surgery
- clean environment following a surgical procedure
What causes redwater disease?
Clostridium haemolyticum
do not confuse with other conditions referred to as Redwater, including Babesiosis
What animals are most commonly affected by Redwater disease? What is transmission like?
cattle and sheep
- endospores are ingested and bacteria lodge in the liver
- when damage occurs to the liver (most commonly caused by liver fluke, Fasciola hepatic), the bacteria replicates
- toxin released results in RBC lysis
What clinical signs are indicative of Redwater disease?
- reddish discoloration of urine due to hemoglobinuria secondary to RBC lysis
- labored breathing
- anemia
- icterus
- dehydration, fever
What 2 lesions are indicative of Redwater disease? How is it treated?
- extremely pale animal with red urine in the bladder and thin, watery blood
- large, necrotic areas in the liver
early treatment with Penicillins or Tetracyclines and antitoxin serum
How is Redwater disease prevented?
- vaccination with 2 doses of bacterin with a booster every 6 months
- control of liver flukes
What causes black disease? What animals are most commonly infected?
Clostridium novyi Type B - infectious necrotic hepatitis
sheep > cattle on a high grain ration
How is black disease transmitted?
- endospores are ingested and the bacteria lodge into the liver (in sheep, Fasciola hepatic plays an important role in creating a desirable environment for the bacterial to grow)
- toxins released cause severe liver damage and result in RBC destruction
What clinical signs are indicative of black disease? What lesion is classical?
- sheep - found dead with no evidence of clinical signs
- cattle - less common, reluctant to move, inappetence, dull and listless appearance
large areas of damaged tissue in the liver appear gray to black with a foul smell
What treatment is recommended for black disease? How is it prevented?
usually no effective treatment as disease often progresses rapidly
2 doses of 7-way bacterin vaccine
What causes tetanus? What animals are most susceptible?
Clostridium tetani
horses and pigs
How is tetanus transmitted?
- organism found widespread in soil
- introduced through injuries such as puncture wounds, castration sites, banding, or dehorning
- incubation period of 10-21 days followed by production of a potent nervous system toxin
What clinical signs are indicative of tetanus?
- extended, sawhorse stance
- difficulty chewing food = lock jaw
- stiff tail
- prolapsed third eyelid
- flared nostrils
- severe muscle spasms/tremors
- sensitivity to noise and movement
How is tetanus diagnosed? Treated?
based on clincial signs, often no postmortem lesions are present
tranquilization, antibiotics (Penicillins), tetanus antitoxin, and supportive care to prevent dehydration or starvation
How is tetanus prevented?
- vaccination
- diligent cleaning of surgical instruments
- placing animals in clean environments after surgical procedures
What causes botulism? What animals are most commonly affected?
Clostridium botulinum –> produces type A, B, and C toxins
horses are most susceptible to Type B toxin
How is botulism transmitted?
introduced though contaminated feed (dead cat or rabbit in silage or hay), where the organism has already produced high levels of toxin in the foodstuff
(wound botulism is rare, but can occur)
What clinical signs are indicative of botulism?
- muscle tremors and fasciculation procede to ascending limb paralysis
- mydriasis, ptosis
- weak tongue
- respiratory paralysis results in death
How is botulism diagnosed?
detection of toxin in serum, intestine, or feed
(no specific postmortem signs)
How is botulism treated?
- no effective treatment for most species
- botulism antitoxin has been used with varying success in horses
How is botulism prevented?
- type B vaccine available: 3 doses at 4 week intervals, booster mares 8 weeks before foaling to produce colostrum to protect the foal for 8-12 weeks
- type C vaccine for mink is available and used in livestock
What species of clostridium most commonly cause enterotoxemia? What animals are most commonly affected?
Clostridium perfringens Type C, B, and E –> normal GI tract inhabitant that only causes disease in certain circumstances
calves, lambs, kids, piglets, or foals less than 7 days old
What clinical signs are indictive of clostridial enterotoxemia?
sudden onset, some calves die without showing symptoms
- weakness
- abdominal distension
- bloody diarrhea
- convulsions
What is clostridial enterotoxemia commonly associated with? What lesion is characteristic?
increase in dietary intake allowing proper growth environment for bacteria
reddened sections of fluid-filled small intestines = purple gut
How is clostridial enterotoxemia treated?
- correct dehydration and electrolyte imbalances with IV fluids
- broad-spectrum antibiotics
- antitoxin
(usually fatal once signs are present)
How can clostridial enterotoxemia be prevented?
herd vaccination
- antitoxin (antiserum) given at birth or to the dam twice with bacterin/toxoid
What causes overating disease (pulpy kidney disease)? What animals is this most commonly seen?
Clostridium perfringens Type D
sheep, goats > cattle (<2 y/o) –> on high grain rations, fattened lambs on rich pastures
(gets its name from rapid carcass decomposition, which leads to pulpy kidneys post-mortem)
What clinical signs are indicative of overeating disease? What is seen on UA? How is it prevented?
- inappetence, weakness
- incoordination
- diarrhea
- nervous signs
- death
glucosuria
2 doses of 7-way bacterin vaccine
What does Clostridium perfringens type A cause?
- jejunal hemorrhage syndrome (hemorrhagic bowel syndrome, hemorrhagic enteritis in adult cattle)
- yellow lamb disease
- intestinal clostridiosis in horses
What clinical signs are seen in different species infected with Clostridium perfringens type A?
COWS - acute death, normal to subnormal temperatures, increased HR, enlarged abdomen (ileus), digested or clotted blood in feces
LAMBS - icterus, weakness, death
How are cows with Clostridium perfringens type A infection diagnosed?
- abdominal U/S = increased small intestinal diameter
- hyperglycemia, hypermagnesemia
- hyponatrema, hypochloremia, hypokalemia
How are lambs with Clostridium perfringens type A infection diagnosed?
hemolysis = anemia, hemoglobinuria, icterus, fever
- death occurs rapidly
What are 2 options for treating Clostridium perfringens type A infection in cows and lambs?
- repeated vaccination - unknown effect
- increase amount of long stem fiver in the diet has decreased the number of cases
Is there a vaccine in the US against Clostridium perfringens type A?
NO
