Week 3 - GI Flashcards
What is the Diagnostic Approach to Diarrhetic Dogs and Cats?
- Categorize diarrhea into small or large bowel or mixed bowel categories
- Determine if diarrhea is primary GI or extra-GI
- Determine if diarrhea is self-limiting/uncomplicated vs. chronic or more severe
What are some Important Questions to Ask During the History for a Diarrhetic dog/cat?
- Appearance of diarrhea to obtain fecal score
-just ask what it looks like bc owners will think diarrhea only is watery - Frequency and duration of diarrhea
-Disease activity index (CIBDAI)
-frequency can help determine small bowel or large bowel dz - Presence of blood, mucous, tenesmus, urgency
- First event or recurrence
- Deworming history
- Vaccination history
- Presence of vomiting
- Travel history
- Appetite
10.Weight loss - small bowel dz
11.Diet history (including treats and supplements)
12.Pruritic behaviors
Purina Fecal Scoring Chart has how many scales?
How many scales does Hill’s have?
1-7, 1 is normal - 7 is watery
Hill’s has 5
What characterizes small bowel disease?
Frequency: normal to slight increase
Volume: normal to slight increase
Blood: melena (gastric, esophageal, or nasal passage bleeding)
Mucous: absent
Tenesmus: absent
Urgency: not really seen
Vomiting: more common with small bowel disease
Weight loss: more common with small bowel disease
What characterizes large bowel disease?
Frequency: marked increase
Volume: very small volume
Blood: hematochezia
Mucous: present
Tenesmus: present
Urgency: more common with large bowel disease
Vomiting: 10-20% dogs with colitis, less common
Weight loss: less common
How do you score the severity of disease in diarrhetic dogs and cats? What 6 variables are considered? This is how a calculate a Patient’s Disease Activity Index
There are 6 variables:
1. attitude/activity
2. appetite
3. vomiting
4. stool consistency
5. stool frequency
6. weight loss
each variable gets a score of 0-3
0=normal
1=mild change
2=moderate change
3=severe change
Summation of variable = CIBDAI score = severity of dz
What are the most common causes of acute diarrhea?
- Dietary indiscretion
- Foreign body
- Infectious
* Parasitic (Coccidia, Giardia, roundworms, hookworms)
* Viral (Parvo/Panleukopenia, circovirus, distemper)
* Bacterial (C. perfringens, Salmonella, Campylobacter) - Antibiotics
- Chemotherapy
Acute diarrhea is more common, is usually self-limiting, and needs only symptomatic treatment. Treatment of acute diarrhea should be supportive because most problems arise secondary to the loss of electrolytes and water, with subsequent dehydration, acidosis and shock.
What are the most common causes of chronic enteropathy in dogs?
Chronic enteropathies: spectrum of intestinal disorders of at least 3 week duration of CS that include inappetence, weight loss, vomiting, or diarrhea. (Chronic diarrhea refers to intermittent or continuous diarrhea of at least 3 weeks duration.)
Top 3:
-food-responsive enteropathy
-antibiotic-responsive enteropathy (dogs mainly)
-steroid-responsive enteropathy
-neoplasia of bowel (lymphoma)
-infection
-miscellaneous: EPI
Fecal flotations are used to ______
assess stool for endoparasites
Gravitational floations (Fecalyzer and Ovassay) are ________ sensitive.
not sensitive
should not use this flotation
run risk of false negative with low worm burden
Centrifugation flotation is ____x more sensitive than gravitational method
7x more sensitive than gravitational method
What does CIBDAI stand for?
Canine Inflammatory Bowel Disease Activity Index
Characteristics of Giardia
- Most common sign is ASYMPTOMATIC animal
- Associated with small bowel diarrhea
- 2 stages – cyst and trophozoite
- Most strains are non-zoonotic (Strains C/D)
– Strains A and B are zoonotic - Diarrhea is often self-limiting
- Refer to Companion Animal Parasite Council (CAPC) for
additional information
How do you diagnose Giardia?
- Microscopic identification of cysts (flotation)
- Microscopic identification of trophozoites (wet prep)
-look for motile trophozoites
-cheap
-NOT sensitive - Direct immunofluorescence assay (DFA) - cysts
-GOLD STANDARD for diagnosing giardiasis
-need fluorescent microscope
-dual assay: will also pick up cryptosporidium (produce oocyst) - giardiasis produces cysts
-crytpo is SMALL (5 microns – about size of RBC) - Enzyme immunoassays (ELISA) - cysts
-HIGHLY sensitive when paired with flotation - PCR – cysts
– KeyScreen GI Parasite PCR (Antech)
–Antech is good for helping knowing resistance/knowing what is zoonotic, detects hookworms, over 20 things…
When is a direct wet prep indicated?
- Indicated for recovery of motile trophozoites:
-Giardia and Tritrichomonas - Giardia – falling leaf motion
Tritrichomonas – haphazard motion - Limitation is sample size
- Use feces < 1 hour old
DO NOT need a lot of poop for sample
- Place a drop of saline on slide
- Mix pepper-corn volume of fresh diarrheic feces
- Add coverslip
- Examine at 10X, confirm diagnosis at 40X
prep should be thin enough to read through
Describe ELISAs for Giardia – what does ELISA look for?
-very sensitive and easy to interpret
-looks for antigen in the the giardia cyst wall - protein 1 (CWP1)
-CWP1 can be detected in cyst-negative feces
-ONLY use for initial diagnosis
–do NOT use for assessment of therapy efficacy
if you want to assess therapy efficacy – visualize cyst via microscope or DFA
Direct Fluorescent Antibody Immunoassay Techniques
- Preserved feces (10% formalin)
- Requires fluorescent microscope
- Requires morphological ID
- Monoclonal vs. cell wall Ag
- Dual assay – Giardia and Cryptosporidium
How do you TREAT Giardia?
- Metronidazole (Flagyl)
-67% effective in dogs (not great)
-2 reasons not to use: only 67% effective and resistance/destruction of microbiome - Fenbendazole
->80% effective - Ronidazole
-also mainly used for Tritrich Foetus - Drontal Plus
-praziquantal, pyrantel, fenbental - Secnidazole
-single treatment
How is Giardia controlled?
- Decontaminate environment
– Quaternary ammonium (QUAT)-containing disinfectants -Roccal; Totil - Treat animals with anti-Giardia drugs
- Clean cysts from coats
- Prevent reintroduction of infection
if wanting to re-test animal to assess efficacy of treatment, do it about 3-4 days AFTER end of treatment
Tritrichomonas foetus in Cats causes large or small bowel disease?
LARGE bowel disease
-31% of cats at recent International Cat Show in US
- Often confused with Giardia
-Dual infection with Giardia in 12% of cats - No cyst stage
- Diagnosis:
– Direct wet preparation
– Fecal culture/inpouch
– PCR - #1 choice for Tritrich – quickest turn around
Clinical Signs of Infection with T. foetus
- Cats are usually BAR, normal appetite, good BCS
- Large bowel diarrhea – semi-formed to cow pie
– ± fresh blood and mucous, ± increased frequency - Malodorous, dribbling of feces
- Anus red, swollen and painful
increased mucous, tenesmus, occasional hematochezia, and increased frequency. The anus is frequently red, swollen, and painful, and fecal incontinence is not uncommon.
Treatment of T. foetus in Cats
RONIDAZOLE
abx that readily kills t. foetus –
-compounded into gel
-side effects: neurotoxicity!
Enteropathogenic Bacteria Associated with Diarrhea in Dogs & Cats
- Clostridium spp.
-clostridium difficle
-clostridium perfringens - Campylobacter spp.
-over 40 species, most are NON-pathogenic
-Camp. Jenjuni - Salmonella spp
-ingestion of raw meat - E. coli - think boxer and French
-Yersinia spp.
-Enterococcus spp.
-Others
How can you detect a bacterial organism or toxin/toxin gene?
- Gram-stain
- Fecal culture
- Common antigen EIA (C. diff)
- Toxin immunoassays
- PCR
Does the presence of enteropathogen infer disease causation?
NOOOO
What are the two Clostridium species we should know about?
Clostridium Perfringens
Clostridium Difficile
Is Clostridium perferingens:
aerobic/anaerobic?
spores?
gramp positive/negative
Clostridium perfringens is a rod-shaped anaerobic, spore-forming, gram-positive bacillus – associated with outbreaks of acute, often severe diarrhea in humans, horses, dogs, and cats.
C. perfringens type A is often associated with
human food poisoning
sporadic diarrhea, canine acute and chronic, large and small bowel diarrhea, and AHDS (acute hemorrhagic diarrhea syndrome)
CPE (C. perfringens endotoxin) is also detected in up to 14% of nondiarrheic dogs – meaning?
C. perfringens role in diarrhea is still a bit unclear
remember: C perfringens is a commensal
How do you DIAGNOSE C. Perfringens?
-ELISA – fecal CPE immunodetection
-fecal PCR for detection of CPE (enterotoxin gene) and the netE/netF toxin gene (also done via isolates of urine)
-lab findings: marked hemoconcentration and normal serum protein levels
-if causes diarrhea, big spectrum of diarrhea
A stained fecal smear is highly sensitive/insensitive?
INSENSTIVE
fecal smears are not sensitive
essentially, useless
Why are stained fecal smears usually done if they’re NOT sensitive?
check for increased neutrophils!
Neutrophils suggests entero-invasive pathogens (salmonella, c. difficile, shigella - mainly for people)
How do you TREAT C. perfringens?
-most patients will get better WITHOUT abx – supportive therapy with IV fluids is just as great
BUT if using abx bc patient was febrile or neutrophilia w left shift and there was black tarry blood (sepsis?) -
-ampicillin/amoxacillin
-metronidazole
-tylosin
use abx 5 days max
Is Clostridium Difficile:
aerobic/anaerobic?
spores?
gramp positive/negative?
Clostridium difficile is a gram-positive, anaerobic spore-forming bacillus
and is the major cause of antibiotic-associated pseudomembranous colitis in people
can be isolated from healthy animals
-more common in people and horses
-POTENTIALLY zoonotic
What are the CS of C. Difficile? What do you DIAGNOSE C. Difficile?
CS:
-symptomatic carriage
-potentially fatal AHDS
-signs of small or large intestinal diarrhea or mixed
Diagnosis:
1. Fecal culture
-rule out CDI, because a negative result from a properly collected and processed fecal specimen has a high negative predictive value
- Antigen ELISA
-easy to perform, rapid, and may be highly sensitive
-if highly sensitive, C. difficile could be ruled out - PCR
RECOMMNEDED DIAGNOSIS:
-Combination of toxin testing by ELISA and organism
detection (culture, antigen ELISA or real-time PCR) is recommended for the diagnosis of CDI in dogs. The chosen ELISA should detect both toxin-A and toxin-B, because toxin-A-negative, toxin-B-positive strains have been documented to in canine isolates.
How do you TREAT C. difficile?
-Antimicrobial therapy is not warranted in dogs with uncomplicated diarrhea (animals that are not
septic, febrile, or immunocompromised)
-DRUG: Metronidazole
–if non responsive – Vancomyocin
What are Campylobacter? (type of bacteria, etc)
Campylobacter spp. are small, microaerophilic, gram-negative, curved rod-shaped bacteria
C. jejuni, C. coli, C. helveticus, and C. upsaliensis
there are over 40 types, MOST are non-pathogenic
How do you DIAGNOSE Campylobacter? CS?
CS
-mucus-laden or watery diarrhea
-with or without blood and leukocytes
-partial anorexia,
-occasional vomiting
-slight fever of 3 to 7 days’ duration.
Severity of the disease is dependent on the number of organisms ingested by the host, as well as previous exposure and development of protective antibody.
DIAGNOSE
1. fecal smear
-slender, curved rods with an “S” shape or sea gull-shaped appearance allows it to be identified relatively easily
-fails to differentiate between Campylobacter spp., or between related organisms including Helicobacter spp., and Anaerobiospirillium spp
- PCR
How do you TREAT Campylobacter?
-majority of cases are uncomplicated and self-limiting and will resolve with supportive therapy alone
-DRUGS: Macrolides (Erythromycin, azithromycin, claritromyocin) or fluoroquinolones
–fluoroquinolones should not be used as first line bc increase in resistance
What are Salmonella?
salmonellae are Gram-negative, motile, non-spore-forming facultative anaerobic bacilli that belong to the family Enterobacteriaceae
Salmonella enterica and Salmonella bongori
ubiquitous organisms
How do you DIAGNOSE Salmonella? CS?
CS
-acute disease although it should be suspected as a cause in any acute or chronic gastrointestinal illness in dogs/cats
-Fever, malaise, anorexia followed by vomiting,
abdominal pain and diarrhea are common. The diarrhea frequently is watery or mucoid and can be
bloody in severe cases.
DIAGNOSIS:
1. Culture
2. PCR - gold standard
traditional diagnosis of salmonellosis is made based on isolation of the organism in conjunction with clinical signs and assessment of potential risk factors such as hospitalization, age, environmental exposure, and antibiotic administration
How do you TREAT Salmonella?
-not routinely treated if patient isn’t immunocompromised, bacteremic, or septic
-DRUGS: fluoroquinolines
Indications for Fecal Culture or PCR (5)
- Acute onset of hematemesis or bloody diarrhea with
systemic signs of sepsis - Zoonotic ramifications
- Hemorrhagic diarrhea in an immunocompromised
patient - Diarrhea affecting multiple pets in household
- Diarrhea following kenneling
- Increased neutrophils on a fecal smear? - human lit
1-3 : suspect infectious causes of blood - start abx
_____% of dogs/cats with a Chronic Enteropathy is Food-responsive Enteropathy
40-60%
- Most common form of chronic enteropathy (40-60%)
Do younger or older dogs usually get Food responsive enteropathy?
Small or large bowel signs? Is the disease activity index usually low or high?
- Younger dogs and cats (median 3.4 years)
- Large bowel signs predominate in 71-86% animals (or mixed bowel)
- Disease activity index is low
What’s the difference between Food Responsive Enteropathy vs. Food Allergy?
-can look clinically IDENTICAL
-more suspicious of food allergy: non-seasonal pruritus in a younger dog with concurrent diarrhea
-that’s why we as about pruritic behaviors
-therapeutic approach is same for both!
What are the 5 different dietary managements/diets for food responsive enteropathies?
- fiber modification - hills w/d
- limited ingredient - (hill d/d - single novel protein source) - ELIMINATION diet
- hydrolyzed - protein is digested/broken down into polypeptides, some times even forms of amino acids (purine e/l) - ELIMINATION diet
- fat-restricted
-esp for lymphangiectasia - highly digestible - Purina EN
How do manage of Food Responsive Enteropathy?
- Dietary therapy is used as both a diagnostic and
therapeutic strategy - Response expected within 10-14 days, some to marked improvement
- Owner compliance is essential
- Maintain therapeutic diet for 3 months/12 weeks before
challenging with a new diet or reintroducing old diet
What is the prognosis for animals with Food Responsive Enteropathies?
- 38/39 dogs alive 3 years after ending study
- 39 dogs switched back to original diet after 14 weeks
of elimination diet trial - No recrudescence of clinical signs in 31/39 dogs
-of the 8 that weren’t successful, most of those dogs were truly food allergic - Younger dogs with less severe disease and predominance of large intestinal signs are more likely to respond rapidly to elimination diets alone
What is the prognosis for animals with Food Responsive Enteropathies?
- 38/39 dogs alive 3 years after ending study
- 39 dogs switched back to original diet after 14 weeks
of elimination diet trial - No recrudescence of clinical signs in 31/39 dogs
-of the 8 that weren’t successful, most of those dogs were truly food allergic - Younger dogs with less severe disease and predominance of large intestinal signs are more likely to respond rapidly to elimination diets alone
4 Negative Prognostic Indicators for Dogs with Chronic Enteropathy
- High clinical activity index
- Hypocobalaminemia (low B12)
- Hypoalbuminemia
- Hypovitaminosis D
Indications for Feeding Hypoallergenic Diets/Hydrolyzed diets?
- Complicated dietary history
- Diagnosis and management of CAFR
- Animal allergic to multiple allergens
Contraindications for routine use:
-$$$
-palatability
What is antibiotic-resistant diarrhea?
-more commonly in dogs and is NOT synonymous with small intestinal bacterial overgrowth (SIBO)
-most are younger to middle-aged (1 to 6 years), medium-to large-breed dogs with chronic persistent or intermittent diarrhea of small bowel or diffuse bowel origin
-GSDs
- Bacterial numbers may be normal or increased
-with ARD - dysbiosis of microbiome, change in composition of microflora, not NUMBER - Young to middle aged, large- and giant-breed dogs
– GSD predisposed
– Defective or deficient IgA secretion? - Small or large bowel clinical signs
- Minimal histological change, but increased
permeability
How do you TREAT Antibiotic-Resistant Diarrhea?
TYLOSIN -might work as a probiotic and have anti-inflammatory properties
cons
-dog does great as long as it is on Tylosin
-if you stop it, it will go back to square one
-clinically makes stool look better, but does not address dysbiosis
SO – try to use more natural therapy – and dietary management in lieu of Tylosin
-dietary changes
-probiotics
-Fecal Microbiota Transplantation
- Mechanism of action unknown
– Increased Enterococcus spp.
– Increased lactic acid bacteria
What is Steroid Responsive Enteropathy?
-IBD – Clinical Criteria
- Spectrum of GI disorders associated with chronic
inflammation of the GI tract of unknown etiology
1. Persistent GI signs (> 3 wks duration)
2. Failure to respond to symptomatic therapies
3. Failure to document other causes of gastroenteritis
4. Histologic diagnosis of benign intestinal inflammation
ideally want biopsy of bowel to confirm IBD
What is the pathogenesis of IBD?
more understood in humans
Overly aggressive acquired T-cell immune responses to a subset of commensal enteric bacteria develop in
genetically susceptible hosts
Environmental factors precipitate the onset or
reactivation of the disease
What are the three factors that play into the pathogenesis of IBD?
Luminal Antigens
-bacteria
Environmental Triggers
Genetics
Basenji has a unique form of IBD – what is it?
Immunoproliferative Enteropathy
Protein Losing Enteropathy – but Basenjis don’t follow rules of the book:
almost every patient with PLE is hypoalbuminemic/hypoglobunemic or normal
BUT BASENJIS are HYPERglobunemic
Food responsive enteropathies and Antibiotics enteropathies are managed _____
EMPIRICALLY
-not collecting biopsies to confirm diagnosis, basing diagnosis on reaction to empiric therapy
What is the Dysbiosis in Dogs and Cats with Intestinal Inflammation?
Gram-positive Firmicutes (e.g., Clostridiales)
» Gram-negative bacteria, predominantly proteobacteria including Enterobacteriaceae
is this shift the chicken or the egg in causing inflammation? – is the shift a cause or consequence of
the intestinal inflammation?
Diagnostic Approach to Dogs & Cats with Steroid Responsive Enteropathies
- Elimination diet trial or fiber-enhanced dietary trial
-most of these patients will most likely have been on diet management already
-BUT use disease activity index - Tylosin trial?
-maybe - Minimum data base
-CBC
-chem
–check cholesterol (hypocholesteral = malabsorption or addison’s)
-urinalysis
–at least a USG – to assess azotemia - Serum Total T4
-every feline patient - Fecal flotation (centrifuge) ± direct wet prep
- Fecal ELISA for Giardia or DFA for Giardia/Crypto vs. PCR
- Fecal PCR or culture (inpouch) for T. foetus
- Serum TLI (EPI), Spec cPL/fPL and B12/folate (assess integrity of distal small bowel)
-help with pancreatitis - Abdominal radiographs/ultrasound
- GI biopsies
B12 (cobalamin) is absorbed in the _____
ILEUM
Folate is absorbed in the ______
JEJUNUM
Measurement of serum B12 (cobalamin) and folate concentrations can be used to evaluate distal small intestinal function/malaborption, because B12 is absorbed in the ileum, and folate is absorbed in the jejunum
For dogs, B12/cobalamin can be decreased in the context of ________ consumption of B12 by bacteria. This then leased to what with folate?
INCREASED consumption - bacteria eat/use B12 (bacterial overgrowth)
Bc the bacteria use the B12, they then produce a lot of folate!
however this test is insensitive to assess bacterial overgrowth
Muscularis should be much smaller than the mucosa. T/F
True
Small cell lymphoma/IBD is in which layer of the bowel?
disease begins in MUCOSA and moves transmurally to the lumen over time, so you’d want to aspirate the mucosa
Collection of Biopsies via Surgery vs Endoscopy has its pros and cons – what are they?
SURGERY
-more invasive
-longer recovery
-more painful
-risk of dehiscence after taking biopsy – higher risk when emaciated and corticosteroids
-benefit: full thickness biopsy
ENDOSCOPE
-partial thickness biopsy
don’t do full thickness biopsies of colon – bc a lot of bacteria!! unless removing a mass
What is the most common phenotype of IBD?
Lymphocyte and plasma cell IBD
if seeing granulomatous/neutrophilic IBD = more of a concern – DO NOT give corticosteroids bc most likely something infectious
How do you manage IBD?
Many of these dogs will respond to treatment with
diet, antibiotics, or immunosuppressive therapy
No reliable means for predicting which dogs or cats
will respond to which treatment
BLEND of dietary and medical therapy
most animals with IBD will need immunomodulatory therapy – usually pred
- Dietary modification
-Elimination or hydrolyzed diets - Antimicrobial therapy
– Tylosin, metronidazole - Immunomodulatory therapy
– Corticosteroids - pred
– Azathioprine - rarely used in dogs, NOT used in cats
–not used in cats bc bone marrow toxic
– Chlorambucil – used in cats with small cell lymphoma, used in conjunction with pred
-adjunct with severe IBD
– Cyclosporine - Miscellaneous- b12, probiotics
Immunosuppressive pred dose in cat/dog is:
1-2mg/kg BID
do not surpass 25-30mg given twice a day
reluctant to give more than 50-60mg a day no matter its size
Prednisone vs Prednisilone
equal in potency
Prednisone is converted to prednisolone in liver
prednisilone is possibly more bioavailable in cats
What are the causes of Hypocobalaminemia?
- Decreased intake
- Decreased gastric acidity (E.g., PPIs)
-B12 must be cleaved from protein, and usually will happen in acidic environment
-PPI takes away acid - Decreased ileal absorption
- Dysbiosis
– Cobalamin important for DNA
replication in intestinal crypts
Probiotics:
- Fortiflora > 100 million CFU’s/sachet
-single string - Proviable 5-10 billion CFU’s/capsule
-7 bacterial strains - Visbiome 112.5 – 450 billion CFU’s/capsule
-8 bacterial strains
Fecal Microbiota Transplantation (FMT)
can be used as some health benefit
What is Granulomatous Colitis?
- Young boxer dogs < 2 years
- Plasma cells, lymphocytes, PAS-positive macrophages
– Avoid immunosuppressive therapy!!!
infectious enteropathy caused by an ADHERENT and INVASIVE strain of E. coli that typically requires fluoroquinolone or other antimicrobial therapy, and not immunomodulatory therapy.
e coli invades macrophages that can’t be phagocytozed
PAS-positive macrophages are pathognomonic for ___
Granulomatous Colitis
PAS stands for periodic acid shift – stain for macrophages
bacteria is in macrophages that cant be phagocytozed
PAS-positive macrophages are pathognomonic for ___
Granulomatous Colitis
PAS stands for periodic acid shift – stain for macrophages
bacteria is in macrophages that cant be phagocytozed
How do you TREAT Granulomatous Colitis?
Treatment of Choice
– Fluoroquinolones
–50% of dogs resistant (ex. Baytril used a lot)
– Increasing antibiotic resistance!
– Must treat for 6-8 weeks!
try to get biopsy and culture abx sensitivity
What is PLE?
Protein Losing Enteropathy
umbrella term, not specific diagnosis
- GI Inflammation
– Severe lymphocytic-plasmacytic enteritis (IBD)
– Histoplasmosis
– Intestinal Pythiosis - GI Ulceration
– Intestinal lymphoma
– Ulcerative gastroenteritis
– Intussusception - Primary intestinal lymphangiectasia
What is Intestinal Lymphangiectasia?
- Small-bowel type diarrhea
- Hypoproteinemia +/- lymphopenia
-usually mainly albumin - Hypocholesterolemia and hypocalcemia
- Malabsorption of fat, fat soluble vitamins possible
-vit a, d, e, k
