Diarrhea Flashcards
What is diarrhea? What are the 4 major mechanisms?
excess fecal water increases fluidity, frequency, and volume of feces
- osmotic
- secretory
- increased mucosal permeability
- dysmotility
What is the difference between acute and chronic diarrhea?
ACUTE = <14 days
CHRONIC = >14 days or intermittent over weeks to months
What different approaches are used for self-limiting (mild) and life-threatening (severe) diarrhea?
little diagnostics and/or supportive treatment –> deworm, dietary modification
more diagnostics and supportive care needed –> HGE, Parvovirus
What are the 6 major differentials for acute diarrhea?
- diet - indiscretion, poor quality, intolerance, change (most common cause!)
- parasites - Giardia, Coccidiosis, Whipworms, Hookworms, Roundworms (more commonly large bowel)
- stress
- infectious - Parvo, feline panleukopenia virus, coronavirus, FeLV/FIV, Clostridium perfringens, Campylobacter
- hemorrhagic gastroenteritis (HGE)
- drugs/toxins - antibiotics, antineoplastics, anti-inflammatories
What history is especially important to gather when diagnosing acute diarrhea?
- diarrhea as a major or minor component - primary GI vs. systemic
- if it’s a new problem
- characteristic of diarrhea - melena, hematochezia, mucus, tenesmus, amount, frequency
- deworming and vaccination history
- exposure to other animals
- known dietary indiscretion - diet change, table scraps, garbage, FB
- other signs - vomiting, appetite
What are 4 important aspects of the physical exam in patients with diarrhea?
- assess hydration
- abdominal palpation - pain, mass, FB
- temperature - fever associated with Parvo
- rectal exam - mass, thickened colon, FB, strictures, visual inspection of feces (blood, mucus, color, consistency)
Diarrhea scores:
What diagnostics are performed in self-limiting and life-threatening diarrhea?
SELF-LIMITING - PCV/TS, fecal (float, Giardia ELISA, cytology, saline examination)
LIFE-THREATENING - CBC/chem/UA, fecal, abdominal radiographs or U/S (usually low yield), fecal parvovirus ELISA, fecal bacterial culture
The cause of hemorrhagic gastroenteritis is unknown. What is thought to be associated? What breeds most commonly present with this problem?
Clostridium perfringens - rarely need antibiotics for improvement
small-breeds - Mini Schnauzers, Yorkies, Dachshunds
What are the most common signs of hemorrhagic gastroenteritis? What 2 things are seen on CBC/chem?
- severe hemorrhagic diarrhea - “raspberry jam” with fetid odor
- severe dehydration
- hypovolemic shock
- abdominal pain/discomfort
- increased PCV > 60% - hemoconcentration
- low or normal albumin - loss from intestines
What treatment is needed for HGE? What improvement is expected?
SUPPORTIVE - aggressive fluid therapy, bland diet once eating for 3-5 days +/- antibiotics
improvement typically seen within 1-2 days, diarrhea may take several days to resolve –> recurrence possible
How is Giardia transmitted? What clinical signs are associated?
fecal-oral
- mild, self-limiting or severe, acute diarrhea
- chronic small bowel diarrhea
- weight loss
How is Giardia diagnosed? What treatment is recommended?
zinc sulfate float, Giardia ELISA, direct saline smear for mobile trophozoites –> ELISA typically remains positive for a long time
Fenbendazole or Metronidazole (can combine) + decontamination (bath, clean environment)
What should be done if a fecal floatation in a patient with diarrhea is negative?
does NOT exclude parasites –> use broad-spectrum dewormer (Fenbendazole, SID for 3-5 days)
What are the most common signs of Clostridium perfringens diarrhea? What diagnostics are recommended?
acute or chronic, large bowel diarrhea that can be hemorrhagic
no perfect test - enterotoxin ELISA, PCR, spores on rectal smear (safety pins, tennis rackets)
How is Clostridial diarrhea treated?
Amoxicillin + Metronidazole + Tylosin
- most commonly done in chronic cases
What kind of diarrhea results from stress? When is this most common?
self-limiting large bowel diarrhea +/- hemorrhagic, tenesmus
stressful events or anxiety - changes in environment, separation anxiety
What are the 6 major parts of acute diarrhea management?
- nutrition - bland diet
- deworming
- probiotics
- antibiotics (?) - may not be needed, recommended if infectious cause is proven, risk for dysbiosis
- fluid therapy
- antidiarrheal - Loperamide (opioid), may not want to mask signs, though –> most commonly used in patients on chemotherapy
only for symptomatic relief from intractable diarrhea
What diet is recommended in patients with diarrhea? What is added for large bowel diarrhea?
highly digestible, low fat - commercial or boiled chicken and rice
fiber
slowly transition back to normal diet after 3-5 days once signs have improved and remained so
What is the difference between small and large bowel diarrhea?
SMALL - normal to slightly increased frequency, increased fecal volume, melena, vomiting, weight loss
LARGE - increased frequency and urgency, decreased fecal volume, mucus, frank blood (hematochezia), tenesmus/dyschezia
(MIXED = signs of both)
What are the 8 major differentials for small bowel diarrhea?
- IBD
- food hypersensitivity
- intestinal neoplasia
- lymphangiectasia
- SIBO, ARD
- Giardia
- Histoplasmosis
- EPI
What are the 10 major differentials for large bowel diarrhea?
- food hypersensitivity
- fiber responsive
- IBD
- histiocytic ulcerative colitis
- irritable bowel syndrome
- colonic neoplasia
- Clostridium
- Tritrichomonas
- Histoplasmosis
- Whipworms
What are 4 systemic causes of chronic diarrhea?
- hyperthyroidism - can look like IBD in cats (weight loss, good appetite, diarrhea)
- liver disease
- kidney disease
- hypoadrenocorticism
diarrhea usually isn’t the main feature of illness (except with atypical Addison’s)
What are the 4 major diagnostics used for chronic diarrhea?
- fecal - float (ZnSO4), direct smear, cytology
- CBC/chem/UA +/- T4, cortisol
- therapeutic trials - diet, deworming, antibiotics
- GI panel - TLI, PLI, cobalamine (decreased), folate (increased) –> best for EPI and assessing cobalamine deficiencies
What imaging is recommended in some cases of chronic diarrhea? When is a surgical procedure needed?
- AUS - palpable abdominal abnormalities, assess intestinal thickness or enlarged LN, FNA
- endoscopy - stomach, duodenum, colon +/- ileum mucosal biopsies –> IBD, lymphoma, lymphagiectasia
celiotomy - full thickness GI biopsies of the entire tract
What are the 3 most common causes of malabsorptive diarrhea?
- intestinal disease - IBD, lymphoma –> nutrients unable to be absorbed across enterocytes
- pancreatic disease - EPI –> lose enzymes responsible for digestion
- endocrine disease - hyperthyroidism, diabetes –> catabolic state, decreased glucose utilization
What is IBD? What signs are most common?
steroid responsive enteropathy that leads to lymphoplasmacytic (+/- eosinophilic) enteritis
- chronic small bowel diarrhea
- weight loss
- variable appetite
- vomiting (cats!)
What diagnostics are recommended for IBD? What treatment is done?
- AUS - intestinal thickening, lymphadenopathy, can be normal!
- biopsies - definitive
Prednisone +/- other immunosuppressives (Budesonide is not systemically absorbed and goes right to the SI)
What is the most common cause of chronic diarrhea in dogs? What treatment is recommended?
food hypersensitivity (responsive) enteropathy
many respond to diet alone –> 2 week minimum trial with hypoallergenic novel or hydrolyzed protein diets
What are the 3 most common intestinal neoplasias? What signs are associated?
- lymphoma (small cell in cats)
- adenocarcinoma
- MCT
- chronic small bowel to mixed diarrhea
- weight loss
- variable appetite
How is intestinal neoplasia diagnosed? Treated?
biopsy
- SMALL CELL (cats) - prednisolone, chlorambucil; good prognosis!
- LARGE CELL (dogs, cats) - chemotherapy; poor prognosis
What signs are associated with lymphangiectasia? What is seen on bloodwork?
- chronic small bowel diarrhea
- vomiting
- weight loss
- some dogs show no GI signs
protein-losing enteropathy - hypoalbuminemia +/- hypoglobulinemia, hypercholesterolemia, lymphopenia
What diagnostics are used for lymphangiectasia? How is it treated?
- AUS - speckling of GIT, thickening
- endoscopy - visualize rice granule-like dilated lacteals
treat underlying disease + low fat diet (prednisone + low fat diet if idiopathic)
What sign is associated with SIBO and ARD? Why is it difficult to diagnose?
chronic small bowel diarrhea
- cobalamine and folate levels are questionable
- may respond to antibiotics - Metronidazole, Tylosin, Amoxicillin, Tetracyclines
What is exocrine pancreatic insufficiency?
acinar atrophy of the pancreas results in loss of enzymes responsible for digesting starch, protein, and fat –> draws fluid into GIT
- may be autoimmune, but does not respond to steroids
What are the 2 most common signs of EPI? What dogs are most commonly affected?
- weight loss with ravenous appetite - may be coprophagic
- voluminous pulpy feces with an orange to yellow color
young to middle-aged GSD and Collies
How is EPI diagnosed? What treatment is recommended?
low TLI (<2.5) +/- low cobalamine (pancreas produces intrinsic factor responsible for absorption)
pancreatic enzymes + cobalamine supplementation
What is the most common sign of Clostridium diarrhea? What treatments are recommended?
chronic, intermittent large bowel diarrhea
- fiber
- Metronidazole or Tylosin +/- long-term Tylosin
What is the most common sign of Tritrichomonas diarrhea? What animals most commonly are affected?
colonizes ileum and colon –> waxing/waning, malodorous large bowel diarrhea (subclinical to intractable)
young cats in batteries or shelters (purebreds)
How is Tritrichomonas diarrhea diagnosed? What treatment is recommended?
- fecal smear (low yield)
- fecal PCR
- in-pouch fecal culture
Ronidazole
What is the most common sign of fiber-responsive diarrhea? What treatment is recommended?
large bowel diarrhea
high fiber commercial diets or addition of psyllium to current diet –> soluble fibers absorbed water and are highly fermentable into SCFAs by bacteria = healthy colonic mucosa and immune function!
What 3 treatments are recommended for large bowel IBD?
- Sulfasalazine - specifically treats inflammation at the lower GIT –> transported to colon and broken down by the flora
- prednisone
- diet - hydrolyzed or novel protein
What is thought to cause histiocytic ulcerative colitis? What does it result in? What dogs are over-represented?
inflammatory responst to E. coli –> ulcerative, granulomatous colitis –> large bowel diarrhea +/- weight loss and anorexia
young (<2 y/o) Boxers and French Bulldogs
How is histiocytic ulcerative colitis diagnosed? Treated?
colonoscopy, biopsies, FISH to highlight E. coli
Enrofloxacin
What are the most common signs of irritable bowel syndrome in dogs? What is the cause?
- episodic large bowel diarrhea
- nausea, vomiting
- distress with abdominal cramping or bloating
stress
What treatments are recommended for irritable bowel syndrome in dogs?
- highly digestible diet supplemented with fiber
- antidiarrheals - Loperamide
- anxiolytics - Librax
- antispasmodics - Hyoscine
A patient presents with continous large volumes of pulpy orange diarrhea. The patient has had a ravenous appetite, but has lost considerable amount of weight. What is the origin of this diarrhea? What is the top differential?
small bowel
EPI –> should have a low TLI and cobalamine
