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)