Exam 3 - GI

Primary clinical signs of gastroesophageal disease

• Dysphagia

• regurgitation

• vomiting

Dysphagia

• difficulty chewing and swallowing

issue with:

• oral cavity

• pharynx

• upper esophagus

Secondary clinical signs of Gastroesophageal disease

• anorexia

• polyphagia

• hypersalivation

• retching

• abdominal pain

• bloat

• weight loss

• melena

• coughing/gagging

Regurgitation Esophagus

• Passive expulsion of undigested food or fluid from the esophagus

• a passive process that occurs without warning

• only neural reflex involved is the gag reflex (to protect the airway)

• classic sign of esophageal disease

• Dysphagia - absent

• ability to drink - normal

• attempts to swallow - single

• pain on swallowing - possible

• abdominal contractions - absent

• time after eating - usually immediate; could be delayed with megaesophagus

• food - undigested; tubular; foamy saliva

• bile (yellow) - absent

• blood - bright red

• hair, plant, other - possible

complications:

• aspiration pneumonia - common

• fluid/electrolyte imbalance - unlikely

Regurgitation with Dysphagia pharynx/upper esophagus

• Dysphagia - present

• ability to drink - poor

• attempts to swallow - multiple

• pain on swallowing - possible

• abdominal contractions - absent

• time after eating - immediate

• food - undigested; tubular; foamy saliva

• bile (yellow) - absent

• blood - bright red

• hair, plant, other - possible

complications:

• aspiration pneumonia - common

• fluid/electrolyte imbalance - unlikely

The Act of Swallowing

• 3 phases

• 1st phase Oropharyngeal phase

  • oral

  • pharyngeal

  • Cricopharyngeal (UES relaxation)

• 2nd phase Esophageal phase

• 3rd phase Gastroesophageal phase

  • GES relaxation

Vomiting stomach

• Forceful expulsion of gastric and intestinal contents through the mouth (CNS reflex)

• dysphagia - absent

• ability to drink - normal

• attempts to swallow - single

• abdominal contractions - present

• time after eating - variable

• food - partially digested; may be undigested

• bile (yellow) - present

• blood - dark brown “coffee grounds”

• hair, plant, other - possible

complications:

• aspiration pneumonia - possible

• fluid/electrolyte imbalance - common

upper vs lower esophageal dz signs

• upper

  • excessive salivation, difficulty swallowing, choking, and food/liquid coming out of the nose

• lower

  • frequent retching, coughing, gagging, and vomiting

Aspiration pneumonia

• regurgitation complications:

  • aspiration pneumonia (common) and fluid/electrolyte imbalance (unlikely)

• vomiting complications:

  • fluid/electrolyte imbalance (common) and aspiration pneumonia (possible)

Clinical vomiting syndromes

Gastrointestinal bleeding:

• iron deficiency/chronic blood loss/microcytic hypochromic anemia

• hematemesis

• melena

• pale mucous membranes and anemia

Delayed gastric emptying:

• Rexongiziable food in vomitus >10 hours after eating

• projectile vomiting

  • common with pyloric obstruction

• bloating

• belching

• metabolic alkalosis

  • net loss of acid from body

Diagnostic methods for Gastroesophageal disease

• Imaging

  • survey radiographs

  • contrast radiography

  • fluoroscopy

    • motiltiy disorders

  • ultrasonography

• GI Endoscopy

  • upper GI examination

    • Esophagus, stomach, proximal duodenum

  • Lower GI examination

    • colon, cecum, distal ileum

GI Endoscopy

• Non-invasive!!

• an atraumatic technique thats an alternative to surgery requiring general anesthesia

• take 10-15 biopsies per are of interest

Diagnosis capabilities:

• gross appearance

• mucosal biopsy

• cytology

• microbiology

• parasite ID

Therapeutic indications:

• foreign body retrieval

• balloon dilation of strictures

• placement of G-tube

• polypectomy

Limitations:

• submucosal and muscularis lesions

• lesions beyond the reach of the scope

Exploratory Surgery

• full-thickness biopsies

• resection of masses

• remove large foreign bodies

• evaluate SI and other abdominal organs

Gastrointestinal Protectants

• Antacids (aluminum hydroxide, calcium carbonate)

• Histamine H2-receptor antagonists

• Proton pump inhibitors

• Sucralfate

Indications for use:

• Gastroduodenal erosions or ulcers

• Reflux esophagitis (heart burn)

• Gastritis

• Hypersecretory states (gastrinoma)

Histamine H2-receptor Antagonists

• suppress acid production in stomach

• Examples:

  • Famotidine/Pepcid

  • Cimetidine

  • Nizatidine (Axid) - 1st choice

  • Ranitidine (not available anymore)

• renal excretion

• product differences

  • Cimetidine: inhibition of p450 enzymes

  • Ranitidine, Nizatidine): GI promotility effects on stomach, intestine, colon

• acid-suppressing effects start to diminish after several days of use

• MOA: inhibits acetylcholinesterase

Proton Pump Inhibitors

• The best we have for decreasing acid production

• Broad spectrum anti-secretory

• Examples:

  • Omeprazole (Prilosec)

  • Lansoprazole (Prevacid)

  • Pantoprazole

  • Esomeprazole

• more effective than H2-blockers

• to prevent rebound acid hypersecretion when stopping treatment, wean patients off PPI’s if used >3-4 weeks

• Downside of PPI’s:

  • peptic hydrolysis of dietary proteins

  • Liberate vitamin B12 from dietary protein

  • suppress natural gastrin release

Sucralfate (Carafate)

• Like putting a bandage on broken bone

• aluminum salt of sucrose sulfate

• mechanism

  • site protective

  • inactivate pepsin

  • adsorb bile acids and pancreatic enzymes

  • stimulates local PG

• binds other oral drugs

  • separate administration by >1 hour

GI Promotility Drugs

• Metoclopramide

• Cisapride

• Erythromycin

• Azithromycin

• H2-receptor blockers

  • Ranidine (Zantac)

  • Nizatidine (Axid)

Indications for use:

• Reflux esophagitis (GES)

• Megaesophagus (cats)

• Functional delayed gastric emptying

• Ileus

• Megacolon

Metoclopramide

• Promotility drug

• Also an anti-emetic

• no colonic motility

GI effects:

• increased GES tone

• increased gastric contractions

• increased peristalsis proximal SI

• no effect on distal GI tract including colon

Cisapride

• Promotility drug

• more effective pro-motility agent than metoclopramide in dogs and cats

• Has NO anti-emetic properties

• compounding pharmacy only

GI smooth muscle stimulated:

• serotonergic (5HT4) effect on post-ganglionic cholinergic neurons

compared to metoclopramide:

• not antiemetic

• better for esophagus (Cats), stomach, SI, colon

Erythromycin

• GI promotility drug

• motilin analogue

• effects on:

  • GES

  • stomach

  • SI

  • colon

• works in dogs

• lower dose than antimicrobial

Azithromycin

• motilin analogue

• used anecdotal since erythromycin price increased

• effects probably similar to erythromycin

Diagnosis of swallowing disorders

• Young animals:

  • congenital disease

    • cleft palate

    • cricopharyngeal achalasia

    • congenital megaesophagus

    • vascular ring anomaly

    • hiatal hernia

  • esophageal foreign body

  • infectious (rare)

• older animals:

  • degenerative disease

    • acquired neuromuscular disorder

    • Idiopathic megaesophagus

  • Neoplasia

• Selected breeds at risk

  • congenital Idiopathic megaesophagus

    • German Shepherd*

    • Shar Pei

  • Acquired Myasthenia gravis

    • German Shepherd*

    • Golden Retriever

  • Cricopharyngeal achalasia / dysphagia

    • Golden Retriever

  • Hiatal hernia / Reflux esopahgitis

    • Shar Pei

    • Bulldog

Oropharyngeal Dysphagia

• structural disorders

  • dental/periodontal disease

  • stomatitis

  • pharyngitis/tonsillitis

  • neoplasia

  • foreign body

  • cleft palate

  • TMJ disease

• 95% of the time there is an underlying structural cause

• functional disorders considered once structural disorders ruled out

• potential clinical findings:

  • abnormalities prehending food or lapping water

  • excess chewing, chomping

  • dropping food

  • repeated swallowing

  • ptyalism

  • gagging, retching

• management

  • treat underlying cause

  • supportive care

    • antibiotics for pneumonia

    • tube feeding (by-pass pharynx)

    • determine conistency of food best tolerated

what is the most common complication of esophageal disorders in dogs and cats?

• Aspiration pneumonia

What is the most common cause of intraluminal esophageal obstruction in dogs and cats

• Foreign body

• especially linear foreign body in cats

Esophageal Foreign Body

• Common FB’s

  • bones, needles, fish hooks, string (cats common), elastic hairbands, hairballs.

• Predilection sites (where esophagus narrows)

  • cervical esophagus

  • thoracic inlet

  • base of heart

  • diaphragm

• Diagnosis

  • clinical signs

    • acute onset

    • regurgitation, dysphagia

    • gagging, salivation

  • rads

  • endoscopy

• methods of removal

  • endoscopy (preferred)

    • remove out of mouth

    • push into stomach

  • surgery

    • esophagotomy (least desirable)

    • Gastrotomy (easier than esophagostomy)

• complications:

  • Esophagitis

  • Perforation

  • Stricture

  • Pneumonia

what is the method of choice for esophageal foreign bodies in dogs and cats? why considered urgent

• Endoscopy is the method of choice for removal of esophageal FB

• minimally invasive procedure

• remove out-of-mouth or push into stomach

• EMERGENCY! esophageal FB can cause a blockage that can lead to difficulty breathing and even death (by asphyxiation)

Esophageal Perforations

• Air in mediastinum or pleural space

• G-tube feedings

  • antibiotics

  • IV fluids

• serial radiographs

• small perforations

  • can heal with symptomatic therapy

  • prognosis good

• large perforations

  • require surgery

  • prognosis guarded

What are causes of esophagitis? what factor determines whether a stricture will form as a consequence of esophagitis? what drugs can cause esophageal strictures in cats?

• causes:

  • Exogenous

    • foreign bodies

    • chemicals

    • drugs

  • Endogenous

    • gastroesophageal reflux (gastric acid)

• strictures form when esophagitis involves deeper layers (submucosa/muscularis) which heal with fibrous tissue

• oral doxycycline, clindamycin tabs (cats)

Treatment options for reflux esophagitis

• Proton pump inhibitor

  • refluxed gastric juice less acidic

• Sucralfate suspension

  • esophageal mucosal protection

• Metoclopramide or Cisapride

  • increase GES tone - less gastroesophageal reflux

• Corticosteroids

  • empirical - prevent healing by stricture

  • use only if severe

• Nutritional support

  • gastrostomy tube - only if severe esophagitis

Esophagitis

• Causes

  • Exogenous

    • foreign bodies

    • chemicals

    • drugs

  • Endogenous

    • Gastroesophageal reflux (gastric acid)

• predisposing causes of gastroesophageal reflux

  • General anesthesia*

  • hiatal hernia

  • brachycephalic obstructive airway syndrome

  • gastric outflow obstruction

  • profuse vomiting

• clinical findings:

  • history

    • recent esophageal FB

    • recent medications

    • general anesthesia

  • signs of acute or chronic esophageal disease

  • caustic injury - oral ulcers

• Endoscopic findings

  • more sensitive than radiography for detecting esophagitis b/c can see subtle reddening

  • lesions

    • muscal erythema, friability, erosions, ulcers, pseudomembranes

  • reflux esophagitis

    • lesions worse in distal esophagus

• general therapy:

  • proton pump inhibitor

  • sucralfate suspension

  • metoclopramide or cisapride

  • corticosteroids

  • nutritional support

Esophageal Stricture

• Abnormal narrowing of the esophageal lumen due to fibrous tissue

• forms when esophagitis invovles deeper layers (submucosa/muscularis), which heal with fibrious tissue

most common causes:

• gastroesophageal reflux during anesthesia

• secondary to esophageal foreign body

• oral doxycycline, clindamycin tabs (cats)

• other (caustic agents, esophageal surgery)

clinical signs

• regurgitation

  • solid food»>liquids

  • progressive

  • 3 to 14 days after esophageal injury

• ravenous appetite

• weight loss

Management:

• Balloon dilation*

  • typically requires multiple dilations under general anesthesia every 5-7 days

• surgical resection

• corticosteroids (empirical)

• treat esophagitis

• gastrostomy tube

• prognosis - guarded to poor

Give your top 3 differential diagnoses for causes of regurgitation in puppies. what diagnostic tests would be most helpful to differentiate these disorders? how to tx and prognosis

• Esophageal stricture (Dx by esophagram)

• Megaesophagus (Dx by thoracic rads)

• Foreign body (Dx by thoracic rads)

• Reflux esophagitis (Dx by ADD)

• Thoracic radiographs - best single test for esophageal disorders

Vascular ring anomaly

• congenital malformation of great vessels and branches that entraps the intrathoracic esophagus

Persistent right aortic arch:

• congenital malformation

• young (<6 months)

• regurgitation (solids>liquids)

  • often first noted when weaned to solid food

• diagnosis

  • Thoracic rads*

  • contrast esophagram* or CT angiography

• treatment - surgical

• prognosis

  • good with surgery (clinical improvement in >90%)

  • worse if delayed surgery or large diverticulum

Esophageal Neoplasia

• Not very common

• types

  • Sarcoma

    • spirocerca lupi

  • squamous cell carcinoma

    • old cats

  • Leiomyoma/sarcoma

    • distal esophagus of dogs

• features

  • asymptomatic (early)

  • obstruction (advanced)

• treatment

  • surgical resection (distal leiomyoma)

• prognosis

  • guarded (except leiomyoma)

What is the most common cause of megaesophagus in dogs

• Idiopathic acquired is the most common in dogs

• symptomatic tx

• supportive tx

• prognosis: POOR due to repeat aspiration pneumonia events

• IF myasthenia, many will have clinical remission and excellent long-term outcome with supportive therapy

• myasthenia gravis MUST be tested for in patients with megaesophagus or functional neuromuscular disorders of the esophagus (Acetylcholine receptor Abs)

• IV LRS

• Abx

• Pyridostigmine (Cholinesterase inhibitor)

why would promotility drugs like cisapride and metoclopramide be unlikely to be effective in the tx of idiopathic megaesophagus in dogs as compared to cats? what is the rational for giving sildenafil to dogs with idiopathic megaesophagus

• Promotilty drugs like cisapride and metoclopramide are unlikely to be effective in the treatment of idiopathic megaesophagus in DOGS because these drugs primarily work by stimulating the GI tract muscles and increasing pressure within the GI tract

• this can be beneficial in CATS with idiopathic megaesophagus as it can help to move food and liquid through the esophagus and into the stomach

• however, in DOGS the esophagus is not a muscle so this type of treatment is not likely to be effective

• furthermore, these drugs may actually make signs worse in DOGS as they can irritate the already weakened esophagus and cause further inflammation

• Sildenafil (phosphodiesterase type 5 inhibitor) decreases GES tone, and regurgitation and facilitates emptying

what are two undelrying causes of acquired megaesophagus in cats?

• Hiatal hernia

• Reflux resophagitis

what common structural diseases of the oropharynx can present with dysphagia? Describe the 2-step diagnostic approach to oropharyngeal dysphagia

• Oropharyngela neoplasia (tumors), FB obstruction, strictures, and trauma

• first a complete physical examination of the pet should be performed in order to identify any obvious signs of oropharyngela disease, such as swelling, inflammation, or tumors

• if the physical exam does not reveal any obvious signs of oropharyngeal disease, imaging such as radiographs or endscopy should be performed to further evlauate te oropharynx and look for any structural abnormalities

Drugs to induce vomiting

• Dogs

  • Apomorphine

  • Dopamine (D2) agonist at CRTZ

  • GOLD standard emetic for dogs; IV or crushed tab in conjunctival sac

• Dogs

  • Ropinirole (Clevor)

  • Dopamine (D2) agonist at CRTZ

  • Eyedrops recently approved for market

• Cats

  • Xylazine

  • a-2 adrenergic agonist at CRTZ

• Cats

  • Dexmedetomidine

  • a-2 adrenergic agonist at CRTZ

  • may be more effective than xylazine

• apomorphine is not effective in cats because they lack dopamine receptors

Why is metoclopramide not effective as a central-acting antiemetic in cats

• Acts on dopamine receptors and cats lack dopamine receptors, therefore it has no antiemetic effects in cats

when is metoclopramide contraindicated

• Intestinal obstruction

What diangostic tests or procedures are useful to identify systemic (non-GI) causes of vomiting

• blood tests, rads, ULS, others

• pancreatitis: pancreatic lipase

• kidney disease: BUN, creatinine, SDMA, UA

• liver disease: ALT, ALP, SBA, T bili

• Diabetes mellitus: serum and urine glucose

• hypoadrenocorticism: Na+, K+, ACTH stim

• Hyperthyroidism (cats): T4

• FeLV/FIV (Cats)

What are indications for antiemetic therapy

• symptomatic control of vomiting (short-term basis)

• profuse vomiting (resulting in fluid, lyte, or acid-base imbalances)

• motion sickness

what mechanism should be considered in a vomiting dog or cat with hypochloremic hypokalemic metabolic alkalosis what is the fluid of choice for treatment (including supplementation)

• 0.9% NaCl (plus KCl)

Causes of vomiting - clinical approach

• primary GI disease

  • distention, inflammation, irritation of GI tract; chemo

  • intestinal tract

  • vomiting center

• Non-GI disease

  • liver, kidney, pancreas, adrenals, endocrine → circulating metabolites or toxins (± other mechnaisms)

  • chemoreceptor trigger zone

  • vomiting center

Clinical features of vomiting

• if vomiting undigested food > 10 hours after eating → delyaed gastric emptying

• if projectile vomiting, forceful ejection → gastric or upper small bowel obstruction

Metabolic consequences of vomiting

• Dehydration

• Electrolyte imabalances

  • gastric juice is rich in K+, Na+, Cl-

    • hypokalemia

    • hypoanremia

    • hypochloremia

• acid-base disturbances

  • metabolic acidosis

    • secondary to dehydration, poor tissue perfusion, lactic acidosis

  • metabolic alkalosis (uncommon)

    • in situations with a net loss of acid from the body

    • gastric and proximal duodenal obstruction

Primary GI disease

• Dietary indiscretion/hyperensitivity

• Acute gastritis or gastroenteritis (AHDS, parvo, parasitic, bacterial, protozoal)

• drug associated

• obstruction (FB, GDV, intussuscption)

• GI ulcers (NSAIDs)

Non-GI disease

• acute pancreatitis

• acute liver disease/failure

• acute kidney disease

• hypoadrenocorticism (dog)

• acute abdomen (all causes)

• sepsis/endotoxemia

• diabetic ketoacidosis

sick acute vomiter RED FLAGS

• disturbing potential cause identified

• vomiting/diarrhea frequent/severe

• unstable/systemically sick

• dehydrated

• unwilling to eat/drink; cant hold anything down

• abnormal PE

Commonly used antiemetics

• Metoclopramide

• Ondansetron

• Maropitant (Cerenia)

• chlorpromazine

• others:

  • Mirtazapine

  • Antihistamines

Motion sickness meds for dogs

• Maropitant (Cerenia)

• Chlorpromazine

• Diphenhydramine (Benadryl)

Vomiting from parvo drug options

• Maropitant (Cerenia) - not under 8 weeks old

• Metoclopramide (if <8 weeks of age)

  • CRTZ

  • promotility effect

vomiting from pancreattis drug options

• Maropitant (Cerenia)

  • vomiting center

  • visceral analgesia

• refractory vomiting - add Ondansetron

Nausea and vomiting from chemo drug options

• Ondansetron

  • especially for nausea

Vomiting cat drug options

• Maropitant (Cerenia)

• Mirtazapine

  • also appetite stimulant

• not metolcopramide

  • unless promitlity action needed

Mirtazapine

• anti-emetic

• appetite stimulant

• nonselective 5-HT2-3 antagonist

GI bleeding with vomiting

• history - NSAIDs and or corticosteroids?

• CBC, chemistry profile, UA

  • regnerative anemia, hypoproteinemia

  • iron-deficienciey (microcytic) anemia (chronic)

  • undelryiing organ disease

• Imaging

  • rads - unremarkable unless perforation

  • contrast rads - mucosal defect

  • AUS - muscoal thickening; organ disease

• Endosocpy or surgery

• Management

  • eliminate risk factors

  • maintain fluid, electrlyte, acid-base balance

  • gastroprotectants

    • PPI (omeprazole)

  • sucralfate

• prognosis

  • guarded to good

  • depends on undelrying cause

Vomiting with Delayed gastric emptying

• Rexongizable food in vomitus >10 hrs after eating

• Mechanical obstruction:

  • luminal or mural lesion

    • foreign body

    • congenital pyloric stenosis

    • antral pyloric hypertrophy

    • gastritis or ulcer

    • neoplasia or polyp

    • GDV

    • secondary to intestinal obstruction

  • extramural compression

    • hepatic or pancreatic inflammation or neoplasia

    • enlarged lymph nodes

    • diaphragmatic hernia

• Functional “Obstruction”

  • Eg. anticholinergic drugs, opiods, parvo, vagal nerve damage (surgery)

• projectile vomiting

• bloating

• belching

• Metabolic alkalosis - net loss of acid from body

• History - acute or chronic, FB exposure, medications

• labortatory features - hypochloremic, hypokalemic metabolic alkalosis

• imaging

  • survey abdominal rads

  • contrast studies

  • AUS- outflow tract

• management:

  • fluid therapy

    • 0.9% saline plus KCI metabolic alkalosis

  • relieve obstruction

  • consider prokinetic drugs only FOR

    • post-op gastric atony (chronic obstruction)

    • functional delyaed gastric emptying

      • no evidence of mechanical obstruction

    • Cisapride preferred

  • Dietary recommendations

    • low fat, canned or liquid

    • small frequent meals

Describe empirical treatment for “Bilious vomiting syndrome” in dogs

• meal before bedtime, metoclopramide, or gastroprotectant (PPI)

How would you differentiate a patient that had GI bleeding due to a sepsis and DIC versus a gastroduodenal ulcer

• physcial exam melna systemic bleeding oral mm hemorrhage of skin, evidence of bleeding elsewhere

• ulcers or erosions

  • Hematemesis, melena, ± anemia

Compare the sensitivity of contrast radiography versus endoscopy in the diagnosis of gastric mucosal erosions and ulcers

• contrast radiography is a less invasive and less expensive imaging technique than endoscopy. it is also widely available and retatvely easy to use

• however contrast radiography is limited in its ability to detect small lesions and subtle mucosal erosions

• endoscopy on the other hand is a much more sensitive imaging technique that can detect small lesions and subtle mucosal erosions

• it is also able to provide a more detailed examiantion and allow for biopsy sampling

• therefore endoscopy is more sensitive than contrast radiography in the diagnosis of gastric mucosal erosions and ulcers

What are potential mechanisms for gastric foreign bodies to cause clinical signs? why are pennies minted after 1983 toxic? what clinical signs might they present for?

• mechanisms cause clinical signs of Gastritis, obstruction, toxins

• Zinc toxicity, check PCV to check for hemolytic anemia

• might present for acute vomiting

Under what circumstances would inducing vomiting with apomorphine for removal of a gastric foreign body in a dog be contraindicated?

• If the foreign body is a sharp or pointed object

What drugs can cause a functional delay in gastric emptying

• Anticholinergic drugs like (atropine and glycopyrrolate)

• Opioids

• Parvo

• vagal nerve damage due to surgery

How do you make the diagnosis of a functional gastric empyting disorder

• Signalment

  • young - congenital pyloric stenosis, FB

  • Old - antral pyloric hypertrophy (dogs), neoplasia

• history

  • acute or chronic, FB exposure, medications

• Laboratory features:

  • hypochloremic, hypokalemic metabolic alkalosis

• imaging

  • survey abdominal rads

  • contrast studies

  • AUS - outflow tract

Why does hypochloremic metabolic alkalosis occur with pyloric obstruction? what type of fluids are indicated for treatment of this acid-base disorder?

• Hypochloremic metabolic alkalosis with pyloric obstruction because the vomiting associated with the obstruction causes a loss of hydrochloric acid (HCI) from the body

• this reduces the concentration of chloride (Cl-) in the extracellular fluid, leading to an alkalosis due to an increase in the pH of the blood

• the most appropriate treatment for this disorder is the administration of fluids containing electrolytes such as sodium chloride or potassium chloride to replace the lost HCl and Cl-

• fluids with a higher sodium content are preferred 0.9% NaCl + KCl

what is the most common malignant gastric neoplasm in dogs and cats?

• Dogs - Adenocarcinoma

• Cats - Lymphoma

Gastritis

• Acute

  • sudden onset of vomiting; healthy

• chronic:

  • chronic vomiting of food or bile; otherwise healhty

• inflammation of the gastric mucosa

  • lymphoplasmacytic most common

  • eosinophilic (parasites hypersensitivity)

  • granulomatous and atrophic are rare

• requires a biopsy for diagnosis

• cause is usually not identified

• Idiopathic most common cause of gastritis

Diagnostic approach:

• CBC, chemistry profile, UA

  • often unremarkable

  • sometimes eosinophlia

• parasite evaluation

  • fecal flotation

  • vomitus (cats - olulanus)

• abdominal imaging

  • usually unremarkable

  • look for other causes of vomiting

• therapeutic trials first, if not response then endocospy and biopsy

therapeutic trials:

• diet trial (min 2-3 wks; ideal 4-6 wks)

  • highly digestible / GI

  • novel (limited) ingredient

  • hydrolyzed

• fenbendazole deoworming

• omeperazole (PPI)

• ± promitlity drug

  • metoclopramide or cisapride

• post-biopsy

  • continue diet therapy

Ulcers or erosions

• Hematemesis, melena, ± anemia

Clinical associations:

• drugs, chemicals, toxins

  • NSAIDs*, corticosteroids*

• increased gastric acid secretion

  • kidney failure, mast cell tumor*, liver disease*, pyloric obstruction/GDV, gastrinoma (rare)

Diagnostic approach:

• history

  • NSAIDs and or corticosteroids

  • CBC, chemistry profile, UA

    • regenerative anemia, hypoproteiemia

    • iron deficiecy (microcytic) anemia (chronic)

    • underlying organ disease

  • imaging

    • rads - unremarkable unless perforation

    • contrast rads - mucosal defect

    • AUS - mucosal thickening; organ disease

  • endoscopy or surgery

management:

• eliminate risk factors

• maintain fluid, electrolyte, acid-base balance

• gastroprotectants

  • PPI (Omeprazole)

  • Sucralfate

• prognosis

  • guarded to good

  • depneds on undelrying cause

Gastric Foreing Body

• common problem

  • dogs > cats

• acute vomiting

• signs due to

  • gastritis

  • obstruction

  • toxins

    • lead, zinc

Diagnosis:

• lab findiings

  • hypochloremic, hypokalamic metabolic alkalosis with obstruction

• abdominal rads

• contrast rads

  • cloth, radiolucent objects

• endoscopy

• surgery

Management:

• medically induced vomiting

  • small objects without sharp edges or points

• endoscopy

  • always radiograph just prior to removal

  • sharp objects could damage esophagus during removal

  • prepare owner that lapartomy will be necessary if endoscopy fails

• surgery

Hairballs (cats)

• common problem

  • higher in long haired cats

• hair swallowed during grooming

• consider excess hair ingestion

  • fleas, pruritic skin disease, overgrooming d/t anxiety

• or GI disease (2nd motility problem)

  • dietary intolerance, IBD

complications:

• Nasopharynx

  • vomited but doesnt come out the mouth

• Esophagus

  • obstruction, esophagitis, stricture

• stomach

• intestine

  • obstruction (partial or ocmplete)

• hairball colitis

• may require surgical removal

prevention:

• dietary management

  • contain fiber

• daily brushing: lion clip

• gastric lubricants

  • laxatone (NOT mineral oil)

• promotility drugs

  • metoclopramide, cisapride

What parasite should always be considered in dogs with large bowel diarrhea

• Whipworms

what parasite should always be considered in cats with large bowel diarrhea

• Tritrichomonas

Define hematochezia, melena, and tenemus

• Hematochezia - blood with normal feces (think polyp!)

• Melena - dark, tarry stool ± blood (mainly caused by the upper GI tract (stomach or SI)

• small bowel diarrhea

• Tenesmus - straining to defecate (diseaseof large intestine)

Why would a serum thyroixin (T4) level be important to evaluate in a 10 year old cat with chornic diarrhea and weight loss?

• Because it can help to diagnose or rule out certain thyroid conditions that could be causing the symptoms

• Hyperthyroidism for example is a common cause of chornic diarrhea and weight loss in cats, and a low serum T4 can indicate this condition

• Low serum T4 levels can also indicate hypothyroidism, which can also cause these symptoms

• by evaluating the T4 serum level, the vet can determine if the cat has a thyroid disorder that is causing the chronic diarrhea and weight loss

Why would you evaluate a serum cortisol / ACTH stimulation test in a young adult dog with unexplained chronic or recurrent GI signs

• A serum cortisol/ACTH simulation test is used to evaluate the function of the adrenal glands

• the test invovles collecting a baseline blood sample and measuring the cortisol level, then administering a synthetic form of the hormone ACTH and collecting a second sample one hour later measure the cortisol response

• an abnormally low cortisol response suggests the presence of Addison’s disease an adrenal insufficiency disorder that can cause chronic GI signs

what type of treatment is universally important in any animal with acute severe small bowel diarrhea

• empirical de-worming is always reasonable

• IV fluids if dehydrated (isotonic crystalloids: LRS, plasmalLyte) - monitor for hypoK

When should Lopermaide (Imodium) use be avoided or used with caution?

• avoid with diarrhea with bacterial etiology or acute diarrhea with secondary invasive bacteria (parvo)

• avoid or use at reduced dose in animals with MDR1/p-glycoprotein defects; increased risk of adverse CNS effects (Collies, Australian Shepherds, other)

Which antibiotics are most commonly used to treat intestinal dysbiosis?

• Metraonidazole and tylosin

Corticosteroids are often indicated as the primary treatment for what chronic GI condition?

• Chronic enteropathy (IBD) immunosppression Tx (Prednisolone)

Why is cobalamin replacement important when it is depleted in animals with chronic enteropathy?

• cobalamin deficiency itseflt can contribute to intestinal disease

  • villus atrophy

  • mucosal inflammation

What are the 3 cellular or tissue targets for canine parvovirus

• rapidly dividing cells intestines, bone marrow, lymphocytes

How would the clinical signs, physical findings, and CBC help distinguish severe paravoviral enteritis from less serious causes of sudden GI upset such as dietary indiscretion

• sudden onset of vomiting or diarrhea (bloody), fever, anorexia, depression, dehydration, death (hypovovlemia; sepsis)

canine parvovirus

• Etiology: CPV-type 2 (a,b,c)

• affinity: for rapidly dividing cells

  • intestines → crypt cell necrosis; vomit/diarrhea

  • bone marrow → neutropenia

  • lymphocytes → lymphopenia; immunosuppression

• transmission

  • fecal-oral; highly contagious

  • survival for months to years in environment, fomites

• Incubation: onset of signs 4 to 7 days

• age: puppies 6 wk to 6 months

• signs: sudden onset

  • vomiting, diarrhea (bloody), fever, anorexia, depression, dehydration, death (hypovlemia; sepsis)

• Diagnose: clinical signs:

  • age plus exposure, leukopenia, neutropenia, lymphopenia, rads (gas distentioin; ileus), fecal antigen immunoassay (SNAP- ELISA technology)

  • fecal antigen immunoassay (ELISA)

  • negative test does NOT rule out disease

    • especially if >10 days after initial infection

    • low viral load; intermittent shedding; antibody coated virus

  • vaccination unlikely to cause positiive

• treatment: persistent vomiting and diarrhea - antiemetic (metoclopramide; ondansetron)

  • neutropenia - antibiotics (IV; ampicillin -slbactam)

  • dehydration hypokalemia, acidosis - IV fluid rehydration; add KCl

  • hypoglycemia - add dextrose to IV fluids

  • nutritional support - feed through vomiting; NG tube

  • hookworms and roundworms - anthelminitc (pyrantel)

Feline parvovrus

• Etiology:

  • Feline parvovirus -95%

  • CPV-2 variants (a,b,c)-5%

• at risk kittens 8-12 wks of age

• pathogenesis - same as CPV except

  • no myocarditis

  • CNS signs if in utero or early neonatl infection

  • cerebellar hypoplasia most common

• peracute form - sudden death from septic shock

• acute form

  • fever, anorexia, lethargy, vomiting, diarrhea (bloody in <15%), dehydration

• final stage - hypethermia, DIC

• diagnose: consistent signalment, history, signs

  • neutropenia and lymphopenia (65-75%)

  • use canine fecal ELISA assay

    • false negatives occur

    • false positives for at least 14 days after vacciantion

• treatment: principles of therapy same as for CPV

  • high mortality rate

    • 50-80% in cats despite treatment

    • 10-40% mortality rate in dogs

• vaccination: vacciantion (MLV or inactivated)

  • 6-8 wks, then every 3-4 wks until 16-20wks

  • booster 1 year after primary series

  • then every 3 years

In a dog with diarrhea what is the significance of a positive fecal culture for Clostridium perfringes? does the presence of Clostridial spores on fecal microscopy confirm the diagnosis of enterotoxigenic Clostridial diarrhea?

• Disease most likely caused by C. perfringens type A producing enterotoxin (CPE)

  • role of CPE in canine diarrhea unclear (cats)

• recently C. perfringesn type A identified which encodes gene for novel net F toxin acute hemorrhagic diarrhea syndrome (AHDS) in dogs (formely HGE)

• combination testing*

  • PCR for toxigenic strains

  • ELISA detection of C. perfringens enterotoxin (CPE)

When should you consider giving antibiotics to a dog with a fecal culture positive for Salmonella?

• NOT recommended for uncomplicated

• YES if systemic signs (fever etc) or immunocompromised animal

• ampicillin + Enrofloxacin (or based on clinical signs)

what organs systems can be involved with histoplasmosis in dogs?

• GI tract (esp. colon)

• respiratory tract

• liver, spleen, lymph nodes, bones, eyes

7 giardia vs tri

Considering efficacy and safety what drug would be considered the overall best choice for treating giardiasis in dogs and cats?

• Fenbendazole

• often used in combination with metronidazole (but this one not as effective and also neutrotoxic)

What type of intestinal foreign body causes aggregation of abdominal bowel loops?

• Linear foreign body

Where does a linear foreign body typically lodge proximally in a cat? How is this different in a dog?

• cats → base of tongue

• Dogs → Pylorus

Palpation of sausage shaped midabdominal mass in a young dog suggests what diagnosis?

• Intussusception

• Ileocolic junction most common location in dogs

• young animals

• usually idiopathic

What disorders can predispose to development of an intussu

• Disease associations:

  • parasites

  • parvo

  • lepto

  • FB

  • Prior GI surgery

What intestinal neoplasm is most likely to cause a focal circumferential stenosing stricture like lesion?

• Intestinal adenocarcinoma

Which neoplasm is most likely to cause diffuse thickening of the wall of a large portion of the small intestins?

• Intestinal lymphoma

What breed of dog has the highest incidence of exocrine pancreatic insufficiency? Age of onset?

• German shepherfd, young adult dogs