Diarrhoea Flashcards

Whe, DD's, tests, diagnosis, treatment

1
Q

DD’s for Diarrhoea in nursing foals

A

Rotavirus

Necrotizing enterocolitis

Salmonellosis

Enterotoxigenic E. coli

Cryptosporidium

Lactose intolerence

“Foal heat” diarrhoea

Gastric ulcers

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2
Q

DD’s for diarrhoea in weanlings and yearlings

A

Lawsonia intracellularis

Rhodococcus equi enterocolitis

Parasitism

Gastric ulcers

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3
Q

Non-infectious DD’s for diarrhoea in horses

A

Foal heat diarrhoea

Mechanical enterocolitis (pica)

Dietary (milk replacer intolorence, lactase def)

Necrotizing enterocolitis

Gastric ulcers

Peripartum asphyxia associated (hypoxic-ischaemic disease, dystocia, premature placental separation)

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4
Q

Infectious DD’s for diarrhoea in horses

A

C. difficile

C. perfringens

Salmonellosis

Enterotoxigenic E.coli

Rotavirus

Adenovirus (esp in SCID foals)

Cryptosporidium parvum

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5
Q

Most likely doagnosis:

Foal has watery diarrhoea but upon inspection is afebrile, still hydrated with a normal mentation and appetite

A

Foal heat diarrhoea

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6
Q

When is the most likely time to see foal heat diarrhoea?

A

Between 5 - 15 days of age

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7
Q

Cause of foal heat diarrhoea

A

Maturational changes of the GI tract:

between days 5 - 15

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8
Q

Cause of asphyxia-associated gastroenteropathies:

A

Hypoxic insult to the GI tract = hypoperfusion

  • unbilical cord compression
  • dystocia
  • red bag delivery
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9
Q

Cause of necrotizing enterocolitis

A

Unknown: Necrotizing insult to the GI

  • Associated with prematurity or hypoxia
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10
Q

Cause of mechanical enterocolitis:

A

Ingestion fo sand, dirt, bedding, the mare’s tail hair =

Mechanical irritation fo the GI mucosa

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11
Q

Cause of dietary intolorence diarrhoea:

A

Feeding milk replacers

Lactase defficiency

  • Associated with loss of brush border of SI: C. difficile & Rotavirus
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12
Q

Cause of Clostridial enteritis (diarrhoea)

A

Clostridium difficile / perfringens

  • Both can be primary pathogens to foals without preceding risk factors
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13
Q

Common finding with Selmonellosis causing diarrhoea

A

Bacteraemia & Sepsis is commonwith GI tract Salmonellosis

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14
Q

Enterotoxigenic strains of E. coli can cause:

A

Bacteraemia & diarrhoea

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15
Q

How does Rotavirus cause diarrhoea in foals

A

Rotavirus affects SI

  • Blunts the microvilli (lactase defficiency) = maldigestion & malabsorption
  • Decreased absorption and increased secretion = diarrhoea
  • Loss of lactase = osmotic component: allows lactose into colon
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16
Q

When does Crytposporidium parvum mainly cause diarrhoea in foals

A

In immune compromised foals:

  • Esp. SCID foals

(severe combined immunodeficiency)

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17
Q

Initial databse for foals with diarrhoea

A

CBC

Lactate

Serum biochemical profile

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18
Q

Thought direction:

Foal with diarrhoea:

CBC - leukopania or leukocytosis

A

Most likely an infectious cause of diarrhoea

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19
Q

Thought direction:

Foal with diarrhoea:
CBC is normal

A

Foal heat diarrhoea

20
Q

T/F: A normal CBC in a horse / foal with diarrhoea rules out an infectious cause of diarrhoea

A

False:

21
Q

Thought direction:
Horse / foal with diarrhoea:

Lactate reading above 2.0 mmol/L indicates

A

Hypovolaemia

Dehydration

Sepsis

22
Q

Tought direction:

Foal with diarrhoea:

Serum biochemical profile normal

A

Foal heat diarrhoea

23
Q

Though direction:

Foal / Horse with diarrhoea:

Possible Serum biochemical profile changes

A
  1. Electrolyte derangement: Metabolic acidosis: GI losses
  2. Azotemia: Prerenal in dehydration
  3. Hypoglycaemia: Decreased milk ingestion and increased glucose consumption with sepsis
24
Q

Possibly confirmatory tests for diagnosing diarrhoea in foals

A
  • Fecal cuture (aerobic & anaerobic)
  • Fecal smear & gram staining
  • PCR for C. perfringens toxin
  • Immunoassay for C. perfringens toxin
  • Immunoassay / electron microscopy for Rotavirus
  • Acid-fast stain / Immunoassay / Electron microscopy for Cryptosporidium parvum
25
Q

Therapeutic goals in foal diarrhoea

A
  • Maintain hydration
  • Maintain adequate organ system perfusion
  • Normalize acid-base balance
  • Normalize electrolytes
  • Provide nutrition
  • Prevent sepsis
  • Direct treatment of causative agent
26
Q

Definition of chronic diarrhoea

A

Persistent or intermittent diarrhoea of at least 1 month duration

27
Q

DD’s for chronic diarrhoea

A
  • Partial large colon obstruction: enterolith
  • Sand enteropathy
  • Infectious cause: parasite / salmonella
  • Colonic fibrosis due to previous severe acute colitis
  • Primary infiltrative / inflammatory intestinal disease
  • Abnormal fermentative function of intestinal flora
  • Gastroduodenal ulcers in foals
  • Rotavirus in foals
  • Hepatic disease
  • Congestive heart failure
28
Q

How does partial obstruction of the large colon cause diarrhoe?`

A

A neterolith or intraluminal neoplasia = irritate the colonic mucosa & intermittently partially obstruct colonic lumen = only softer feces can pass around the obstruction

29
Q

How can sand enteropathy cause chronic diarrhoea

A

Sand irritates and inflames the colonic mucosa

30
Q

How do parasites , salmonella and rotavirus cause chronic diarrhoea in foals (general)

A

Damages the colonic mucosa and cuase chronic inflammation of the colonic mucosa

31
Q

How can a primary infiltrative / inflammatory intestinal disease cause chronic diarrhoea

A

It impairs the normal absorptive capacity of the colonic mucosa

32
Q

How does colonic fibrosis cause chronic diarrhoea

A

It also impairs the normal absorptive ability of the colonic mucosa

33
Q

How does gastroduodenul ulcers in foals cause chronic diarrhoea

A

GDUD alters the absorptive ability of the SI which may overwhelm the colonic absorptive capacity in the less mature colon of a foal

34
Q

How can systemic diseases like hepatic disease and congestive heart failure result in chronic diarrhoea

A

It may cause portal hypertension, altering the fluid dynamics in the colonic vasculature and impairing water aborption

35
Q

What to consider during a diarrhoea work-up

A

CBC

Serum biochemistry profile

Transabdominal US

Abdominocentesis

36
Q

Expected findings during a diarrhoea work-up

A

CBC:

Normal OR show evidence of chronic inflammation: leukocytosis, mild aneamia, hyperfibrinogenemia

Serum biochemistry profile:
Metabolic acidosis - bicarbonate losses

Electrolyte derangement: Hypo-kalemia / -natremia / -chloremia / -calcemia

TSP - elevated due to hyperglobulinemia = chronic inflammation

TSP - decreased = enteric protein loss (hypoalbuniemia)

Liver function - SDH (sorbitol dehydrogenase), GGT, Serum bile acid concentration

Abdominal US:

Fluid in colon / cecum

Mural thickness increase (>5mm) for colon & SI

Abdominocentesis:

Normal OR increased nucleated cell count and proteins: consistent with intestinal inflammation

37
Q

List possible definitive diagnostic techniques for chronic diarrhoea in horses

A
  • Sand enteropathy - abdominal radiographs
  • Parasites - faecal floats and sedimentations
  • Salmonella - Serial fecal PCR / culture
  • GDUD - Gastroduodenoscopy
  • If weight loss, hypoalbuminemia, intestinal mural thickening - D-Glucose / D-xylose absorption test
  • Exploratory celiotomy if all above are negative or inconclusive
38
Q

Acute general treatment for chronic diarrhoea if a specific etiology is determined

A

Parasites - deworming

Laxatives - sand enteropathy

Enrofloxacin (5mg/kg IV Q24) - Salmonella

Immunosuppressive therapy with corticosteroids - IBD

Surgical removal of an enterolith

Surgical resection of focal intestinal neoplasia

Gastroprotectants for GDUD in foals

39
Q

Acute general treatment for chronic diarrhoea if no specific cause was determined

A

Presumptive deworming

Transfaunation - help correct the intestinal flora

Diet change - alter colonic flora and VFA production

40
Q

What are the risk factors for clostridial diarrhoea

A

Treatment with antimicrobial agents - C. difficile

41
Q

History:

Pyrexic horse with inappetence and acute diarrhoea (diarrhoea appears to be intermittently bloody), moderate amount of gastric reflux with SI distension on rectal palpation

Most likely DD’s

A

Colitis

Proximal enteritis

Clostridial diarrhoa

42
Q

Which Clostridium is most likely to cause diarrhoea and why

A

C. difficile

Produces two toxins

  • Type A (enterotoxin)
  • Type B (cytotoxin)

Also associated with antimicrobial-associated colitis in adults

43
Q

Risk factors for clostridial diarrhoea

A

Use of antimicrobials - C. difficile overgrowth

Ingestion of organisms or spores from the environment

44
Q

How do clostridial toxins cause diarrhoea?

A

Clostridial toxins directly damage enterocytes = inflammation and necrosis of colonic epithelial cells = damages the mucosal barrier = systemic exposure to the toxins & loss of fluids, electrolytes and plasma proteins into the intestinal lumen

45
Q

Acute general treatment of clostridial diarrhoea

A
  • Fluid therapy
  • Anti-inflammatory & Antiendotoxic (Flunixin meglumine)
  • Antimicrobial: Metronidazole @ 15 - 25 mg/kg PO Q8
    (Vancomycin if the Clostridia is resistant to metronidazole)
  • Biosponge - bind clostridial toxins in vitro
46
Q

Acute general treatment of diarrhoea in a neonatal foal

A
  • Fluid therapy: Bolus 10-20mL/kg over 20 minutes
  • maintenance @ 2-6 ml/kg/h
  • Correct metabolic acidosis (caused by hyperlactatemia due to hypoperfusion)
  • Treat hyperchloremia with sodium bicarbonate
  • Antimicrobial therapy - metronidazole if clostridial
47
Q

Recommended monitoring of a foal being treated for diarrhoea

A

PCV / TP

Blood glucose (decreased intake and increase use esp in sespsis)

Lactate (hypoperfusion / dehydration)

Electrolytes

Gases (Metabolic acidosis)

USG

Therapeutic drug monitoring for foals on aminoglycosides