Diagnosing GI disease Flashcards
What’s the time cut-off for acute disease vs chronic?
> 2-3 weeks
acute is anything under 2 weeks
Main steps to diagnosing. (5)
Choose an appropriate diagnostic tool.
Differentiate primary from secondary
Determine the level of the disease
Prognosis (double the time the dz has been present & you have an approximation of duration for GI tract stabilization)
Treatment (symptomatic)
If you have diagnosed Giardia in 1 dog in a family of dogs, how do you tx?
Only treat the dog with signs of infection. It’s no longer recommended to treat all of the exposed.
1st line tx is fenbendazole, 2nd line is metronidazole
How often should an adult dog be dewormed?
Either quarterly, or only when necessary based on fecal test results.
If the dog eats raw food or hunts, it should be dewormed monthly.
1st step of making a diagnosis:
1 step: anamnesis/history, physical examination, determine the level of severity of dz, empirical treatment (e.g. treatment trial for endoparasites)
Level of the disease mild/moderate/severe.
2nd step of making a diagnosis:
2 step: blood and fecal samples, diagnostic imaging, disease-specific treatment
3rd step of making a diagnosis:
3 step: diagnostics under GA, endoscopy, laparoscopy, laparotomy, CT – diagnostic and therapy
How long to fast a GI patient for bloodwork?
6h for you basic panels, but minimim 12h for thorough GI panels (such as enzymes, B12, folic acid etc.)
Even longer than 12h in some tricky GI cases.
Applies to both dogs and cats.
ELISA vs PCR
ELISA (Enzyme-Linked Immunosorbent Assay) detects proteins (like antibodies, hormones, or viruses) using antibodies and a color change reaction. It’s used for diagnosing infections, allergies, and detecting biomarkers.
PCR (Polymerase Chain Reaction) detects DNA or RNA by amplifying genetic material, making it highly sensitive
In short: ELISA = detects proteins, PCR = detects genetic material.
What should you assess during physical exam, especially in GI patients?
BCS as well as muscle condition score!
In what imporatnt disease does muscle wasting occur gradually in?
lymphoma
What should you check in bloods in all vomiting cases?
electrolytes
Diagnosing step 1:
Tx for mild symptoms?
Tx for moderate/severe symptoms?
Tx for mild symptoms - empirical.
Tx for moderate/severe symptoms - dz-specific tx.
What do we NOT use in primary GI patients?
Antibiotics!
ONLY is GI patients with sepsis!
Diagnosing step 2: lab work portion. Elaborate.
See attached image:
Bloodwork
Fecal sample
If indicated, also urinalysis
Always do a blood smear too!
Diagnosing step 2: diagnostic imaging and other modalities. Elaborate.
x-rays: minimum 3 views
U/S: systemic approach for entire GI tract
What does linear foreign body look like on xray (other than plication)?
gas-filled, distended loops of bowel
Diagnosing step 2: elaborate on ultrasonography.
Use a systematic approach.
Recommend 6-12h fast.
Look for free fluid/gas.
Assess GI motility.
Check for obstructions.
Assess GI structure (e.g. intestinal wall thickness)
U/S guided sampling
U/S can also help you decide what type of biopsy procedure you should go for: if change is in mucosa, use endoscopy; if change is in deeper layers, go for full-thickness biopsies via laparascopy.
If you have elevated renal values with low blood proteins, what diagnostics should you do next?
urinalysis and kidney U/S
What is the canine microbiome dysbiosis index?
The dysbiosis index (DI) is a quantitative PCR-based assay that can be used to assess the feline or canine fecal microbiome in individual patients.
The DI quantifies the fecal abundance of seven bacterial taxa as well as the total bacterial abundance. These bacterial taxa are commonly altered in chronic enteropathies (CE) and after broad-spectrum antibiotic use.
The DI provides reference intervals for these bacterial groups and additionally calculates a single number that expresses the extent of intestinal dysbiosis (Table 1).
The DI correlates negatively with species richness, i.e., a higher DI indicates lower microbial diversity.
Tx of crypto and eimeriosis in cattle?
crypto - halofuginone
eimeriosis - toltrazuril
Intussusception, foreign body, obstruction can all cause a secondary GI condition seen within the wall of the intestines on U/S…
lymphangiectasia
Loss of intestinal layering and increased wall thickness on U/S can indicate…
lymphoma
But full diagnosis requires full thickness surgical biopsies.
First place lymphoma changes a cat’s intestines…
ileocolic junction
Mesenteric lymph nodes round out from their normal bean shape and enlarge too.
intussusception on U/S
manifests in the transverse orientation as a ‘target sign’ or ‘donut sign’ representing layers of intestine within the intestine
Can occur due to foreign body, obstructions, infectious diseases.
When should you NOT use barium contrast?
When you suspect perforation/ulcer as barium is harmful outside of the GI tract. Instead use iodine.
Diagnosing step 3: involves…
endoscopy: e.g. mucosal biopsies
laparoscopy: e.g. full thickness biopsies
laparotomy: e.g. full thickness biopsies
CT: for giant breeds, masses
Differences between CT and U/S for GI tract pathologies.
U/S better for ulcers and assessing intestinal wall thickness etc.
Both CT and U/S are good in their own right so choice should depend on the case.
E.g. you can’t necessarily diagnose lymphoma with only CT and no U/S.
