SA Approach to Vomiting Flashcards
(22 cards)
Differentiate Regurg. from Vomiting:
-Regurgitation: Passive expulsion of contents from mouth, pharynx, and esophagus
-Vomiting: Active expulsion of contents from the stomach
How do you get stomach contents to move backwards (Vomit):
-LES relaxes
-Stomach contracts
-UES relaxes
-Food is propelled out of the esophagus & mouth
Vomiting facts:
-In conscious animals, the airway is protected by the epiglottis. In unconscious animals, the airway is unprotected, increasing the risk for aspiration pneumonia
-Vomiting evolved as a mechanism to protect the body from toxic substances that have been ingested
-Rodents & Rabbits can regurg. but not vomit!!
-Dogs, cats, & ferrets can vomit!!
-Causes: Substances circulating in the blood trigger the brain’s emetic center to induce vomiting
Triggers of Vomiting:
-Induced vomiting
-Opioids
-Vestibular disease
-Circulating toxins (Such as uremic, hepatic, enterotoxins, and endotoxins)
-GI disease (Can directly trigger the emetic center)
4 Major Inputs to the Emetic Center:
-CRTZ (Chemoreceptor Trigger Zone): Brain senses circulating trigger = VOMIT NOW; Can receive input form the oculovestibular center
-Oculovestibular Center: Gives input to the CRTZ & Emetic Center; “The word is spinning, make it stop”
-Cerebral Cortex: “Ew, that makes me nauseated”
-GI Tract: GI Disease; Sends a ton of signals to the Emetic Center; Receives order from EC to initiate vomiting
-When Emetic Center receives too many inputs, or vomit-inducing inputs, it initiates vomiting in the GI tract
Inducing Vomiting in Dogs:
-Apomorphine (D2 Agonist): Won’t work in cats as its a dopamine agonist; Can give with maropitant to reduce nausea
-Opioids: Hydromorphone (ENK6)
-Vestibular disease: Cerenia, but antihistamines are better
-Circulating toxins (CRTZ Nausea): Maropitant, ondanestron, metclopramide (reglan)
-GI disease (Serotonin released): Maropitant, ondansetron (KNOW THIS ONE), reglan
Inducing vomiting in cats:
-Dexmedetomidine IM, xylazine (Alpha 2 agonists)
-Vestibular disease/car sickness: Meclezine (dramamine) or benadryl (H1 antagonist)
-Circulating toxins: Maropitant, ondanestron, NOT metoclopramide (reglan) because cats don’t have dopamine receptors
Anti-Vomiting Drugs:
-Maropitant (NK1 antagonist)
Big Categories for GI Causes of Vomiting:
-Reverse Flow –> Obstruction
-Disruption of the GI Barrier –> triggers the emetic center
Reverse Flow –> Obstruction:
-If things can’t move forward, then they must move backward
-Mechanical Obstructions: FB, GDVs, Mesenteric torsion, neoplasias, pyloric stenosis
-Functional Obstructions:
-You MUST rule out mechanical before you can diagnose functional obstruction
-Gastric Ileus: Decreased motility secondary to other GI issues; Clinical signs (Vomiting, regurgitation, anorexia); Diagnosis (POCUS abdomen and see markedly dilated stomach, abd. rads, abd. US)
-Intestinal Ileus: Decreased intestinal motility secondary to Cats (Chronic enteroopathy, pancreatitis), Dogs (Severe pancreatitis or gastroenteritis); Clin signs (Vomiting, maybe regurgitation, anorexia); Diagnosis (Abd. US is preferred)
-Constipation: Decreased colonic motility secondary to dehydration or GI disease; Clin. signs (Vomiting after attempting to defecate due to increased vagal tone, tenesmus); Diagnosis (Abd. rads +/- US)
-Bilious vomiting syndrome: Decreased intestinal motility when fasting leads to reflux of duodenal contents into the stomach; Clin. signs (Early morning vomiting before breakfast); Diagnosis (Clin. signs/timing, response to treatment, rule out other causes); Treatment is to decrease fasting time
Disruptions of the GI Barrier which trigger the Emetic Center:
-Inflammation
-Infectious
-Diffuse Neoplasias
Inflammation:
-Acute (Gastritis, enteritis, and colitis): Dietary indiscretion/changes, drugs, toxins, dietary allergies, may be adjacent to pancreatitis or peritonitis. Clin. signs include vomiting, anorexia, diarrhea, and no evidence of chronic disease
-Chronic (Chronic enteropathies, IBD, PLE): Food responsive enteropathy (including fiber & probiotics), IBD, PLEs, Clinical signs include chronic vomiting, weight loss, diarrhea, and anorexia/hyporexia. Diagnose by ruling out non-GI causes with abd. rads, abd. US, response to treatment, and endoscopic biopsies (recommended for PLE)
-Gastric & intestinal ulcerations: Secondary to acute or chrnoic inflammation, toxins, drugs, caustic substance ingestion, gastrinoma, and helicobacter (In guinea pigs & ferrets); Clin. signs include vomiting, hematemesis, and melena; Diagnose mostly via clin. signs, but endoscopy is gold standard although invasive, also may use the patient’s response to treatment
Infectious Causes of Vomiting:
-Viral
-Bacterial
-Fungal/algal
-Protozoal
-Parasitic
Viral causes of Vomiting:
-Affects young & unvaccinated young dogs typically
-Most viral infections will also cause diarrhea!!!
-Parvovirus: Vomiting, diarrhea in puppy or unvaccinated young dogs; Diagnosis via SNAP tests or fecal PCR
-Canine distemper: Starts with resp. signs, progresses to GI signs and then progresses to Neuro. signs; Diagnose with a conjunctival swab for inclusion bodies, respiratory disease PCR panel
-Feline Panleukopenia Virus: Vomiting and diarrhea in a kitten; Diagnose via SNAP tests and fecal PCR
-Systemic Virulent Feline Calicivirus: Oral ulcerations, oculonasal signs, vomiting, anorexia, diarrhea, & fever; Diagnose with PCR on swabs from nose, throat, conjunctiva, or feces
Bacterial causes of Vomiting:
-Enterotoxins: Cause inflammation and circulate in blood
-Enteroinvasive: Cause direct damage to mucosa
-Types: E. coli; Salmonella; Shigella; Yersinia; Clostridium; Campylobacter; Helicobacter (stomach specific bacteria)
-Clin. signs: Vomiting blood; Diarrhea; Weight loss
-Diagnose: Fecal cultures are not helpful in Small Animals
Fungal/algal causes of Vomiting:
-Histoplasmosis: Disseminated or primary GI; Cats –> most commonly get from indoor potted house plants!!! Dogs –> inhale spores from soil; Southern US is most common region; Clin signs include chronic wasting, fever, anorexia, vomiting, and diarrhea; Diagnose using abd. US, organism ID on cytology, endoscopic biopsy, blasto urine antigen test cross reacts with histo, serum immunoassay in cats
-Oomycete: Pythium insidiosum (focal, large masses); Right at pylorus or further down in the ileum by the colon are common locations; Common in Cali. and in large breed dogs; Clin. signs are vomiting, weight loss, and diarrhea; Diagnose with abd. US, CT, and serology
Protozoal causes of Vomiting:
-Toxoplasma Gondii in cats: Often self-limiting diarrhea; Once they have it, they always have it!!! Clin signs include vomiting, diarrhea, weight loss, neuromuscular disease, and hepatobiliary disease; Diagnose with PCR, IgG, and IgM antibody testing
Parasitic causes of Vomiting:
-Stomach:
-Physaloptera (Dogs & Cats): Ingesting invertebrate insects; Adult worms develop in stomach; Causes chronic vomiting; Diagnose by IDing worm in vomit, fecal smear (not float!)
-Ollulanis tricuspis (Only cats): Ingesting other cat infected vomit; Adult worms develop in stomach; Chronic vomiting; Diagnose baermann sedimentation on stomach fluid or vomiting; Cannot be found in feces!
-Intestines:
-Heterobilharzia Americanum (Dogs): Ingest contaminated meat/water; larvae migrate across the intestinal wall causing granulomatous inflammation; Clinical signs include vomiting, hematemesis, diarrhea, hematochezia, anorexia, PU/PD, and weight loss; Diagnose with fecal PCR , fecal saline sedimentation (not float), and abd. US
-Any intestinal parasite that causes diarrhea can also cause vomiting!
-Dogs and cats with large worm burdens can vomit intestinal worms (roundworm and tapeworm burdens are most common)
Diffuse Neoplasias as a cause of Vomiting:
-Small cell lymphoma or Mast Cell Neoplasias: Large cell lymphomas cause a solitary mass; Small cell lymphoma are more common in cats; Clin. signs include vomiting, weight loss, and diarrhea; Diagnose using AUS, FNA of LNs or spleen, endoscopy is needed to differentiate lymphoma from IBD; Intestines that look “like bacon or swiss rolls”
-Large scale between mild IBD –> Small cell lymphoma
Non-Gi Causes of Vomiting:
-Go to CRTZ
-Acronym: HELP TAKEN
-Hyperthyroidism
-Endotoxin
-Liver disease
-Pancreatitis
-Toxin
-Addison’s
-Kidney disease
-Electrolyte/acid-base
-Neurologic
Medications commonly used for causes of vomiting:
-Anti-nausea Medications (Only for vomiting): Cerenia; Ondansetron; Metroclopramide (Not for cats!); Acepromazine; Chlorpromazine; Meclizine; Diphenhydramine
-Medications to INDUCE Vomiting: Apomorphine (dogs); Dexmedtomidine (Cats; reversal is atipamezole/antesedan); Hydrogen peroxide (dogs, not cats!!)
