Vomiting vs Regurgitation

What are characteristics usually associated with regurgitation?

usually immediately or soon after eating so it looks like undigested food covered in saliva, no prodromal phase, no retching, no abdominal contractions, high risk of aspiration pneumonia, rare presence of bile, and possible cervical esophageal distension (observed on left side of neck)

What are the clinical signs usually associated with regurgitation?

dysphagia or odynophagia, repeated swallowing attempts, and hypersalivation

What are characteristics usually associated with vomiting?

occurs at any time after or in between meals, presence of bile, abdominal contractions, less risk of aspiration pneumonia

What are the clinical signs usually associated with vomiting?

nausea, retching, and no cervical esophageal distension

What are the two possible origins of regurgitation?

esophageal and pharyngeal diseases

How are esophageal diseases presented?

abnormal function (megaesophagus), obstruction (foreign body or stricture), inflammation (esophagitis)

What is an obstruction causes esophageal disease mainly in puppies?

vascular ring anomaly

How are pharyngeal diseases presented?

regurgitation is accompanied by dysphagia

Why is a ravenous appetite a clinical sign seen with regurgitation?

food does not reach the stomach

What is required to visualize esophageal abnormalities such as obstruction, abnormal function or dilation?

chest radiographs however it does not rule out all esophageal diseases

What are the three phases of vomiting?

prodrome, retching, vomiting

What is another word for vomiting?

emesis

What happens during the prodrome phase of vomiting?

increased intestinal pressure causes giant retrograde contraction into stomach; nausea

What happens during the retching phase of vomiting?

lower esophageal sphincter relaxes with low thoracic pressure but abdominal pressure still increases leading to first failed attempt at vomitting

What happens during the ejection/vomiting phase of vomiting?

epiglottic closes to eject material while closing off airway

What can vomiting be initiated by?

humoral or neural pathway

What is the humoral pathway?

toxins in blood activate the chemoreceptor trigger zone (CRTZ)

What is the neural pathway?

vagus nerve in GI tract, noxious smells or nervous feeling due to cerebral cortex, and vestibular system

What is the species difference between the vestibular system in dogs versus cats?

dogs vestibular system activates the chemoreceptor trigger zone while in cats it directly activates the vomiting center

What are the afferent pathways with vomiting?

emetic center located in medulla oblongata with CRTZ, visceral receptors with sympathetic vagus innervation, vestibular apparatus, cerebral cortex

What are the efferent pathways with vomiting?

excitation/inhibition of smooth muscles with vagal innervation and myenteric neurons

What is the trifurcation of vomiting to diagnose?

stomach/intestine, pancreas/liver, or metabolic

What are the most common differentials for acute vomiting?

gastrointestinal obstruction (foreign body), dietary indiscretion (acute gastroenteritis of dietary origin), and acute pancreatitis