510 Midterm 3 - GI System

Define Bolus

Food in mouth/esophagus + saliva

Define Chyme

Bolus + HCl + enzymes (in stomach)

List the main components of the GI tract

Oral cavity

Esophagus

Stomach

Small intestine - Duodenum, Jejunum, Ilium

Large intestine - (Vit production) Cecum, Colon, Rectum, Anus

How does the stomach differ in Ruminants?

4 chambered:

Rumen

Reticulum

Omasum

Abomasum

How do the following accessory organs contribute to digestion?

Pancreas

Liver

Gal bladder

Pancreas: releases enzymes into Duodenum/Jejunum

Gal bladder: storage of bile; released into Duodenum/Jejunum

Liver: releases enzymes into Jejunum; production of bile

What part of the tooth does Gingivitis infect?

The gingiva at the Gingiva Sulcus

Compare Plaque to Tartar/Dental Calculus

Plaque = bacterial coating on the teeth - but usually friendly

Dental calculus = Tartar = mineralized plaque = very irritating to Gingiva

What is Gingivitis?

How does it progress to Pariodontitis?

Gingiva = infectious, reversible inflammation of the gum margins

-Changes in pH of mouth —> multiplication/invasion of pathogenic bacteria —> further inflammation —> weakened tooth attachment (periodontitis)

Pariodontitis = “around” the “tooth” “inflammation”

Irreversible loss of gingival attachment + bone dissolving/reabsorption - Once the ligaments and alveolus become inflamed —> gum recedes to expose tooth roots + bone no longer protected, begins to dissolve/get reabsorbed —> tooth falls out b/c nothing to hold on to (wiggly is painful too)

What are the 4 stages of tooth decay?

Stage 1: Gingivitis - sulcus depths still normal (gums red)

Stage 2: Gingival hyperplasia - plaque becomes mineralized

Stage 3: Periodontitis w/vertical bone destruction

Stage 4: Periodontitis w/horizontal bone destruction

Clinical Sings for Gingivitis/Pariodontitis

• Halitosis (bad breath)

• Reluctance to eat/chew hard food, oral pain, loose teeth

• Pawing at mouth

• Head shyness (pain)

• Increased saliva, possible bloody 

• Sneezing/nasal discharge - hard palate (roof of mouth) = floor of nasal cavity; infection can spread to nasal passage in a top tooth is involved

• Facial Swelling

• Tooth loss

Diagnostics for Gingivitis/Pariodontitis

• Oral exam (req sedation)

  • Assess Tartar/inflammation

  • Probe (to assess sulcus depth)

  • Radiography - should not see any exposed root or bacteria in the alveolus

Treatment for Gingivitis/Pariodontitis

• Dental scaling - using medical grade equipment to scrape calculus off

  • Must clean BELOW the gumline to be effective 

• Clean debris around tooth

• Extract loose teeth

• Antibiotics

Prevention for Gingivitis/Pariodontitis

• Practice oral hygiene once adult teeth come in (~2yrs old)

• Brushing - can even be an enriching experience for the animal 

  • Wipes not as effective b/c don’t get under the gum line

  • ** Pathology lives in the Sulcus; removing only the external calculus = purely cosmetic 

• Gels, water additives 

• Routine “dentals” by vet/tech

• Feed hard, crunchy food or greenies/other chew toys

• Tx gingivitis early (as soon as gums are red)

• Vaccination (still controversial)

Esophageal Disease - CHOKE

Define the condition

How does it differ for horses and cows

Partial/total esophageal obstruction

Super dangerous in Cows b/c they fore-gut ferment and need to belch the gas out. Horses can fart it out. W/o eructation, cows bloat and can die

Causes of Choke

• Food - incomplete chewing/lubrication (maybe eating too quickly b/c competing for food), or tries to eat whole fruits—> get stuck/expands in esophagus

• Foreign body (FB) such as wood etc hidden in food 

• Drugs that decrease smooth muscle motility

• Trauma/inflammation

• Scar tissue

• Neoplasia (tumor/mass growth) in the neck 

Clinical signs of Choke, Horse

What similar condition should you rule out?

• Anxious, sweating salivating (salivating most indicative of GI issue vs. other)

• Stretching the neck - stuck food is painful

• Swelling of throat 

• Nasal discharge w/NON DIGESTED food

  • When head is lowered, food comes back up since can’t go into stomach

• Coughing - when food is suck, epiglottis can’t close —> food/liquid in trachea —> coughing —> pneumonia (dangerous!!)

• ***CAUTION - Can look like RABIES***

  • Also includes sad/depressed, head hanging, foamy saliva (can’t swallow)

Clinical signs of Choke, Cow

• Bloat = Accumulation of free gas (type2) or froth (type 1) in the rumen

  • (bloat can be result of other things too tho, more later)

  • Can’t eructate = very dangerous 

  • Microbes in rumen produce >10gal gas/hr; Rumen itself is only ~50gal

  • Horses ferment later in digestive process so gas can come out back end

  • Frequency in goats < sheep << cows

  • Expansion of rumen compresses other organs and blood vessels

    • i.e. Caudal Vena Cava which drains blood from the back of body to return to heart, gets pushed up against spine

    • Diaphragm/chest cavity compressed —> smash lungs —> can’t take deep breath

• Abdominal distention (especially the left side)

• “Downer cow” - cow literally can’t stand and collapses; respiration + circulation both impacted 

• Abdominal pain, Anxiety, Resp. distress

Diagnostics, Choke

• Palpation of neck - esophagus lays along left side of trachea/neck

• The distention itself is a huge clue

• “Ping” in left side

• Endoscopy - if NG tube won’t go all the way to stomach, you know theres a blockage 

• Radiography

Treatment of Choke, Horses

• NPO (Nothing Per Os)

• Hydrate w/IV fluids - sometime dehydration is actually the cause (less lube)

• Gently massage (careful if object is sharp!)

• Irrigate with stomach tube

• Muscle relaxants/anti-inflammatories

• Sedation/anesthesia (to limit anxiety)

• Antibiotics - especially tin aspirating/inhaling food

• Surgery not commonly necessary

• Warm water lavage through NG tube

• Antibiotics and NSAIDS

Treatment of Choke, Cows

• EMERGENCY

• Trocar - insert through rumen —> gas/froth release

  • “Pop the balloon”

• For froth: DSS/mineral oil/veg oil

• Once air is released, can deal with any esophageal obstruction

• Rumenotomy

Complications of Choke

• Pressure necrosis - While the grass sits in the esophagus, it rubs and wares at the ET

  • Constant pressure can cause the skin to die

  • More likely to get another blockage in that same place later

• Asporation pneumonia

• Rupture - increased risk if any pressure necrosis from a previous blockage

• Stricture (narrow spot in the esophagus)

Prevention, Choke

• Dental health - painful teeth = less chewing = swallowing bigger pieces of food

• Avoid: cubes, pellets, feeding after exercise, without water, or < 4hrs post surgery 

• Slow their eating —>  smaller bits + more saliva to lubricate 

  • Ex: Rock/salt block in feeder, hay nets 

• Keep away from orchards (no whole fruit)

Stomach Disease - Bloat (cows)

Differentiate between Primary and Secondary

• Primary = Frothy bloat, due to diet - traps normal fermentation gases in a foam

• Secondary = free gas bloat = caused by physical prevention of belching/eructation

Diagnostics, Bloat

Must asses if version 1 or 2

Trocar —> Foamy material = primary ; Gas = secondary 

Treatment, Bloat

• Primary bloat = always an emergency —> try to decompress with trocar

  • Administer antifoaming agent

  • If not enough —> emergency rumenotomy

• 2ndary: if non emergency —> stomach tube + antifoaming agent 

Prevention, Bloat

• Avoid young legumes (prebloom = less fiber, more moisture) - alfalfa, clover

• Avoid grains (lead to slime/foam)

• Feed antifoam

Gastric Dilatation/Volvulus (GVD)

Define the condition/signalment

Whos most affected?

• = Stomach distended with gas/food/fluid (G) —> twists (V)

• Most common in large/giant breeds with deep, narrow chest cavities

• Risk increases with age (starting at 2yrs)

• 1/3 fatality rate; treat ASAP 

Etiology/causes, GDV

• Chest conformation

• Diet - large/single meals; better to split food into two meals per day

  • Also avoid feeding near exercise (before or after)

  • Avoid dry food —> thirsty —> chug water —> extra full stomach = unstable 

  • Avoid elevated food bowls

• Volvulus (now pathological, w/o was just bloat)

  • Stomach twists clockwise

  • Both inlet and outlet get kinked - can’t swallow OR vomit

  • Nerve/artery damage —> necrosis 

  • Compression of lungs and veins

Clinical Sings, GDV

• Anxious, uncomfortable

• Nonproductive retching

• Hypersalivating 

• Abdominal distention/pain

• Weakness, collapse (circulatory system and lungs not working properly)

  • No blood flow —> no ATP production —> no muscle contraction —> “Shock” (collapse)

  • Pushed up against diaphragm

• HR and RR increase to try to compensate for lack of efficient circulation

Diagnostics, GDV

• Attempt but failure to vomit

• Prolonged capillary refill time (CRT)

• Abnormal mucous membranes 

• Radiographs - gas appears dark on an X-ray; Flesh = gray ; Bone = white

Treatment, GDV

• Decompress stomach 

  • Stomach tube if not too twisted; can damage if is tho so be careful

  • Trocar 

• Treat circulatory deficiency

  • IV catheter (thoracic limb preferred due to circulation block) fluids

• Surgery - expensive tho so focus on prevention

  • Can do a gastropexy @ time of neuter; sow stomach to side of abdominal wall

• Pain management

Prevention, GDV

• Feeding: small amounts, w/o large volumes of water, not near exercise, not in elevated bowl

  • Try for high quality, non fermentable food

Intestinal Diseases = Canine Parvovirus 

Define the condition

Where did it originate?

Who’s most affected?

• = Infectious enteritis = inflammation of the Enteron AKA intestines 

  • Originated/mutated from Feline Panleukopenia in 1978

• Super contagious!!

• Spread via Fecal-Oral Route

• Primarily occurs in puppies 6-20 weeks old (window of vulnerability)

• Recall: Small intestine = simple columnar ET covering Villi (folds) for increased SA

  • Virus completely destroys these cells —> Primary Barrier GONE, no more villi visible 

  • Blood and other tissue fluids from body leak out to intestinal tract

  • Microbes + toxins from food leak into body

Clinical Signs, Canine Parvovirus

• Note: Incubation is 3-7 days for the virus; can spread to others unknowingly during this time

• Acute onset - quick once it actually starts

  • Fever, depression, anorexia, vomiting, bloody diarrhea, malodorous stool (stinky!)

• Dehydration

Diagnostics, Canine Parvovirus

• Specific: ELISA test (fecal) - specifically tests for CVP Ag

  • Recent vaccination can lead to false positive 

• Nonspecific: CBC - tests WBC counts, virus attacks bone marrow —> dec counts

Treatment, Canine Parvovirus

• Supportive care = help body fight better but on its own

• IV fluids - must avoid over-hydration

• Antibiotics

• Antiemetics (Emesis = vomiting) - V takes energy the animal doesn’t have right now

• NPO, then slowly introduce bland diet

Prevention, Canine Parvovirus

• Sanitation - Bleach, Parvo specific cleaners, Foot baths

• Deworming - decreases susceptibility/harm if infected

• Vaccination (special regimen)

How does the puppy vax schedule for Parvovirus differ from others? Why?

• Typically vax at 6-8 weeks

• For Parvo tho: Start @ 4 weeks —> every 3-4 weeks until 16-20 weeks old (maternal Ab gone)

• How? Have developed Modified Live Virus that’s “High virus titer, less attenuated”

  • Overriedes maternal Ab

  • Potentially more harmful tho if bad reaction to vacc