LA Vomiting/Regurgitation: True vomiting & Regurgitation Plus

Question 1

Vomiting:

Answer 1

-Pathophys: CRTZ stimulation; Visceral afferent stimulation
-Clin. Signs: Before (Inappetence, increased salivation, retching) During (Abd. contracture)
-Horses: Poorly developed reflex; High pressure esophagus and high tone lower esophageal sphincter
-Ruminants: Toxicities (Cardiac glycosides!! Organophosphates; Sneezeweed); Intestinal causes are more rare (Diaphragmatic hernia of reticulum; Actinobacillus rumenoreticulitis; Around ororumen tube when they have GI disease)

Question 2

Regurgitation:

Answer 2

-Mainly esophageal
-Pathophysiology: Esophagus (Mechanical obstruction, functional obstruction, inflammatory); Reticuloruminal (Occurs normally; If increased then is likely an outflow obstruction but these are uncommon); Gastric (Foals gastric outflow/duodenal obstruction)
-Clin. Signs: Frothy saliva and food; Nose in horse & camelid, soft palate conformation, bilateral discharge; Mouth and/or nose in ruminants
-Differentials: Dysphagia!!! URT; LRT

Question 3

Esophageal Obstructions:

Answer 3

-Common in horses and cows, but uncommon in camelids and small ruminants
-Clinical signs and PE: In general external palpation (Can feel it if its in the cervical region); Secondary dehydration, bloat, and aspiration pneumonia
-Horse: Anxious, neck extended, gagging, retching, coughing, odynophagia, ptyalism, and sweating
-Cow: Anxious, ptyalorrhea, swinging head (violent), and staggering
-NGT/NRT/ORT: Inability to pass a tube is diagnostic for obstruction; Gives you information on where the obstruction is; NO information on what the obstruction actually is
-Clin. Path:
-Horse: Especially when going on >24 hours; Dehydration; Saliva high in bicarb, chloride, sodium, and potassium result in acidosis initially then alkalosis due to hypochloremia, hyponatremia, and hypokalemia
-Cow: Especially when longstanding; Dehydration; Saliva high in bicarb, sodium, and potassium leading to acidosis, hyponatremia, and hypokalemia
-Diagnostics: US not super helpful; Rads can be helpful; Endoscopy provides a definitive diagnosis!!

Question 4

Choke:

Answer 4

-Horses are more likely to choke on roughage than cows!!!
-Location: Narrowing; Cervical (Cow cranial cervical especially); Thoracic inlet, base of heart; Nearing cardia (In horse)

Question 5

Choke in Horses:

Answer 5

-Obstructing material is usually roughage (Hay, alfalfa cubes, beet pulp)
-FB less common (Apple, carrot, wood, stone, etc…)
-History and risk factors: Dentition –> poor mastication; Prior esophageal trauma; Wolfing/gulping/food competition; Feed changes, sedation, dehydration
-Treatment: #1 goal is to resolve obstruction!!! Sedation, anxiolysis –> head down; Muscle relaxation (Oxytoncin, buscopan, intraluminal lidocaine); Lavage (Standing, GA, Cuffed tube); Supportive care, time, repeat; Surgery only if necessary; Then slow refeeding with soft food initially
-Complications: Increase with duration –> resolve ASAP; Aspiration pneumonia; Ulceration (Circumferential –> increased risk of stricture); Esophagitis, dilation proximal to site, rupture
-Recurrence: Up to 37%; Highest first 24-48 hours
-Prognosis: Survival is good (78%); Potential for chronic/recurrent choke –> dietary modifications
-Prevention: Dental care, diet modification, feed alone, large rocks to slowdown eating

Question 6

Choke in Cows:

Answer 6

-Obstruction: Often large chunks of apple, potato, beet tops, and corn cob
-Secondary bloat: Can be acute, severe –> life threatening (trocarization); Can slowly develop with incomplete obstruction
-Treatment to resolve: Sedation –> head low similar to horse; Retrieve through mouth (Massage retrograde, hand; Corkscrew/pincher attachment probang; Remember rabies is a ddx!!); ORT/NGT and time if feed material (temporary rumen fistula); Rumenotomy and snare, lavage
-Aftercare: Soft diet; Feeding through tube or rumen fistula to allow esophagus to heal
-Complications: Similar to horse
-Prognosis: Good long term unless mucosal damage is bad