veterinary medicine hemorrhagic bowel syndrome enteritis in lactating cattle clostridial infections

1. JEJUNAL HEMORRHAGIC SYNDROME

2. ln the past few years, hemorrhagic bowel, bloody gut, or jejunal
hemorrhage syndrome has emerged sporadically in individual, high-
producing dairy cows in early lactation
The disease is seen most commonly in adult dairy cows early in
lactation, although cases occasionally occur in late lactation or the dry
period
The clinical course is per acute, with anorexia, colic, drop in milk yield,
hemorrhage into the intestine, and sudden death despite aggressive
supportive and surgical treatment

4. ETIOLOGY
The etiology of HBS is uncertain but believed to be multifactorial
Clostridium perfringens type A, a normal inhabitant of the bovine
digestive tract, has been incriminated as a causative agent
Another proposed potential causative agent is Aspergillus fumigatus,
a common fungus in feed and forages

5. •The primary lesion is similar to that caused by C perfringens in
young, rapidly growing animals and consists of an acute, localized,
necrotizing, hemorrhagic enteritis of the small intestine that leads to
development of an intraluminal blood clot
•The clot causes a physical obstruction, with proximal accumulation of
intestinal fluid and gas and development of abdominal distension,
dehydration, and varying degrees of anemia
•The hemorrhagic enteritis is progressive
•Ischemia and necrosis extends through the intestinal wall, and, if
untreated, there is a fibrinous peritonitis within 24–48 hours,
followed by profound toxemia and death
PATHOGENESIS

6. EPIDEMIOLOGY
•Hemorrhagic bowel syndrome occurs sporadically, primarily in mature
lactating dairy cows in North America and Europe, but it has also been
recorded in beef cattle
•Highest incidence rates during the cold months of the year
•Possible risk factors are those associated with management practices
aimed at achieving high milk production, such as high fermentable
carbohydrate content of the diet and feeding a total mixed ration
•Mortality in general is high, with 80%–100% of affected animals dying
within 48 hours

7. CLINIAL SIGNS
•Sudden anorexia and depression
•Sudden and pronounced drop in milk production
•Abdominal distention and pain, with kicking at the abdomen
•Dark, bramble jelly-type feces, scant in amount
•Dullness and weakness progressing to recumbency

8. •Clinical findings include depression, dehydration, increased heart and
respiratory rates, and pale mucous membranes
•Abdominal distension of the right flank may be mild but progresses
rapidly
•Due to the acute onset, there can still be good rumen fill, but the
rumen is atonic, and fluid sounds may be elicited by succussion over the
right abdomen
•Dark red blood clots with a sticky bramble jelly-type consistency are
present in the feces

9. •In cases of complete and prolonged intestinal obstruction, the rectum
appears dry and sticky, only containing small amounts of dark feces
•Distended and firm loops of intestine may be palpable on deep rectal
examination
•On laparotomy, a segment of the small intestine of variable length is
dark red and distended, with a serosal surface covered by tags of fibrin
•The small intestine proximal to the affected segment and the
abomasum are distended with gas and fluid

11. •Ultrasonography may aid in diagnosis
•The hemogram is variable; serum biochemistry reflects obstruction of
the upper small intestine and sequestration of abomasal secretions with
resultant hypokalemia and hypochloremia
•Serum L-lactate concentrations are often markedly elevated, with
values >5 mmol/L

13. •Other causes of physical or functional obstruction of the small intestine
(e.g., intusseptions, cecal dilatation and volvulus)
•Diffuse peritonitis from right-sided torsion of the abomasum or torsion
at the root of the mesentery
•Diseases causing melena (e.g., abomasal ulcers)
DIFFERENTIAL DIAGNOSIS

14. Surgery to localize small intestinal loops affected by hemorrhagic
bowel syndrome and manually reduce and dislodge blood clots within
the intestinal lumen appears to be the most efficient treatment
Fluid and electrolyte therapy is also indicated
Antibiotics like ceftiofur are somewhat effective
In advanced stages, resection of the affected segment of the intestine
may be required
Prokinetic substances to enhance intestinal passage administered
parenterally combined with single or repeated large
IV doses of heparin to prevent new clot formation in the intestinal
lumen may be used postoperatively
A short-term protective effect of a C perfringens type C and D vaccine
against hemorrhagic bowel syndrome in some herds has been reported
anecdotally
TREATMENT AND CONTROL

15. There are currently two hypotheses regarding the
participation of A. fumigatus in this disease:
1.As a primary contributor to the intestinal lesion
2. As an agent that impairs the cow’s immune system, thereby
facilitating or inciting whatever disease process triggers HBS
Anecdotal reports suggest that the incidence of HBS can be
reduced on dairies following the introduction of a feed supplement
(Omnigen AF®) into the ration
This product has recently been demonstrated to improve certain
indicators of immune function in the white blood cells taken from
immunosuppressed sheep and cattle