Vomiting Flashcards
primary GI causes of vomiting
- dietary indiscretion
- GI foreign body
- GI neoplasia
- pancreatitis
- infectious gastroenteropathy
- IBD
extra-GI causes of vomiting
- liver disease
- renal disease
- hyperthyroidism
- toxins
- Addison’s
- heartworm
is vomiting due to small bowel disease more common in dogs or cats
cats
dogs - diarrhea w/ small bowel disease
what are the two main pathways of the vomiting reflex
- humoral (blood borne) –> CRTZ
- neural –> vomiting center
what are the major visceral receptors
5HT3
substance P
located in the GIT, peritoneum, bile duct epithelium
is dopamine receptors more relevant for vomiting in dogs or cats
dogs - D2 receptors are a strong component of vomiting reflex
what vomiting-related drugs are used in dogs that are not effective in cats
- apomorphine - D2 agonist, induces vomiting
- metoclopramide - D2 antagonist, antiemetic
what components send input to the vomiting center
- cerebral cortex - anticipatory emesis
- vestibular nuclei - motion sickness
- CRTZ - blood borne
- pharynx & GIT - gastroenteritis
cat vs dog vestibular nuclei pathway
cats: direct input from vestibular nuclei to the vomiting center
dogs: vestibular nuclei feeds input to the CRTZ which sends info to the vomiting center
regurgitation vs vomiting
regurgitation:
- passive (no contractions)
- no prodromal nausea
- seconds to hours after meal
- undigested material
vomiting:
- active
- prodromal nausea
- minutes to hours after meal
- undigested or digested material
what are signs of severe disease in vomiting patients
- fever
- melena/hematochezia
- weakness
- anorexia < 48 hours
- abdominal pain
- vomiting of coffee grounds or frank blood
- pale, icteric, or muddy MM
- enlarged abdominal organs or peripheral LNs
diagnostics for acute vomiting
- PCV/TP
- glucose
- azostix
- USG
- abdominal radiographs
- +/- fecal float
- +/- resting cortisol
management of acute vomiting
- isotonic crystalloid fluids
- LF diet
- antiemetics
- broad spectrum Ab (young animals)
should vomiting animals be given gastric acid suppressants
only if worried about a GI bleed (iron deficiency anemia)
diagnostics for chronic vomiting
- minimum database
- fecal floatation
- serum T4
- serum B12/folate
- FeLV/FIV
- abdominal US/radiographs
- resting cortisol
- serum bile acids
- spec PLI
- liver aspirate/biopsy
- GI biopsy
pros and cons of endoscopy
pros: less invasive, can visualize the stomach, duodenum, proximal jejunum, and able to collect many punch biopsies
cons: can not collect full thickness biopsies,
pros and cons of laparotomy
pros: can get full thickness biopsies
cons: more invasive, only a single biopsy collected, have to use opioids (post op ileus)
gastritis
non specific inflammation of the stomach
what is a very common infectious cause of gastritis
helicobacter pylori
common GI bacteria in HEALTHY dogs/cats but can cause gastritis
diagnosis of H. pylori
gastric biopsy
histopath: lymphofollicular gastritis
treatment of H. pylori
triple therapy x2 weeks
- clarithromycin
- metronidazole
- PPI
can IBD affect the stomach
yes
when is the use of antiemetics indicated vs contraindicated
- intractable vomiting
- risk of aspiration pneumonia
- secondary acid-base or electrolyte derangements
contraindications:
- obstruction
- toxin ingestions
gastric acid suppressants
- PPIs (omeprazole, pantoprazole)
- H2 antagonists (famotidine)
what are problems with H2 blockers
- tachyphylaxis - develops tolerance within 1 week
- less effetive/potent than PPIs
- CYP450 inhibitors - affects metabolism of other drugs
administration considerations for PPIs
requires acidic environment to work - administer 30m min prior to a meal
do not give prior to sucralfate (also needs acidic environment)
must taper before stopping
prostaglandin E1 analogues
misoprostol
increases muscoal blood flow and mucus production
decreases gastric acid secretion
less common in vet med
metoclopramide
antiemetic + weak prokinetic
- 5HT3 antagonist
- D2 antagonist
- 5HT4 agonist
do not use as antiemetic in cats
does not work on colon (constipation)
administer as CRI
ondansetron
potent antiemetic
- 5HT3 antagonist
IV or SQ
diphenhydramine
motion sickness antiemetic in DOGS only
- vestibular nuclei
- histamine H1 antagonist
does not work in cats
maropitant
antiemetic in dogs and cats
- NK1 antagonist
good for opioid induced vomiting, motion sickness, anesthetic sparing
does NOT resolve nausea, only stops vomiting
