GI Diseases Flashcards
what are the components of the circle of nutrition?
patient, diet, feeding management
if a pet has vomiting or diarrhea, how should we alter feeding methods? how has the theory on this evolved over time?
PAST: NPO
- Discontinue food & H2O for 24-48 h
- Small amounts of H2O every few hours
- If well tolerated: small amounts of food - No vomiting/diarrhea: increase gradually
Purported advantage:
- Reduce pancreatic secretions
- Reduce gastric distension
– abdominal pain - Bowel rest
CURRENT: EARLY ENTERAL NUTRITION – PO/tube
-Feed through vomiting/diarrhea
Purported advantages:
- Preservation of gut integrity & function
- Improved immune function
- Reduced bacterial translocation
- Attenuated release of inflammatory mediators
- Reduced rate of infection & infectious complications
- Reduced duration of hospitalization
ideal feeding frequency
Small meals frequently: 3-6 meals/day
- Reduce gastric distension
- Decrease gastric secretion
- Reduce nausea, vomiting, GE reflux
- More effective assimilation (digestion + absorption)
digestive problems caused by megaesophagus
-Peristalsis fails to occur properly
-Enlarged esophagus
-Does not push the food down to the stomach
-Food stays in esophagus
-Eventually food is regurgitated, enters lungs through breathing, decays in esophagus
goal of a feeding plan designed for a patient with megaesophagus
- Meet nutrient requirements
- Maintain ideal body weight
- Minimize regurgitation > prevent aspiration pneumonia
key nutritional factors for patients with swallowing disorders due to obstructive lesions or aberrant motility:
-higher in fat > overall volume of food is smaller, helps as less volume required to be pushed down esophagus
-high protein > helps with tissue repair
Energy density: >4.5 kcal/g
Fat: >25%
Protein: >25% for dogd, >35% for cats
> often growth foods are good for this, or cat food for dogs
*note: never feed a dog food to a cat
key nutritional factors for patients with swallowing disorders due to esophagitis/gastroesophageal reflux:
less fat, as fat makes food sit in the stomach for a long time
fat < 15%
How to determine food ‘form/consistency’ for patient with megaesophagus? considerations
Try various food consistencies
> best texture for individual patient
Liquid/gruel: > Not stimulate secondary peristalsis
> Higher risk for aspiration pneumonia
GENERALLY BEST:
Dry food / Moist food formed into large boluses
> Stimulate swallowing reflex maximally
> secondary peristalsis
best feeding method/ frequency for patients with megaesophagus:
Small volume, multiple small meals
Upright position
Animal-related risk factors for GD/GDV
Large or giant breed
Deep chested
Male gender
Purebred
Older age (6-7 y)
Rapid eating
Recent car journey (within 24 h)
Recent time in boarding kennel (within 24 h)
Personality (fearful, nervous or aggressive)
Esophagal motility disorders
Previous GI disease (IBD)
Excessive belching or flatulence
Dietary risk factors for GD/GDV
-infrequent meals / large food volume at once
- only single food form
- only dry food
- no snacks, treats
- small kibble size
- fat in first 4 ingredients
- Citric acid in first 4 ingredients
Dietary indiscretion
Elevated food bowl
Eating too fast
Gulping water
Aerophagia
Thin body condition
- higher body weight
- periprandial exercise
what to advise owner about animal related risks of GD/GDV
ADVISE OWNER: No matter what you do, the risk still exist Teach owner what signs to look for
how to deal with a dog with GDV risk: type of food, amount, frequency, other considerations
Food: Highly digestible, 12-15% DM fat
Amount: Based on idBW 31 kg
Go home: MER: 1.6 x RER
Divided into 3 to 4 meals daily
Eliminate rapid eating
Restricted exercise / avoid car rides in close association with
meals
Prevent dietary indiscretion
Warn owner!!
How to deal with a dog with megaesophagus: type of food, amount, frequency, other considerations
Food:
Recovery, working/sporting dog, small breed growth food, cat food
Purina Essential Care Puppy Formula Protein: 31.70 %DM
Fat: 20.10 %DM
Amount:
Based on ideal body weight 27kg
DER: 1.6 x RER
RER = 70 x kg0.75
Frequent small meals
Offered from a bowl placed on the edge of the table
how to eliminate rapid eating in dogs
Decrease competitive eating
Placing large balls or rocks in food bowl
Feeding from a muffing tin
Special made food bowl (Brake-Fast®)
Mix of dry and wet food
Greater kibble size (>30 mm for giant-breed dogs)
4 categories of GI diets
- Highly digestible /. low residue diets
- fat restricted diets
- elimination diets
- fibre-enhanced diets
what is digestion and what components go into it? what are the goals of a highly digestible diet and how do its macronutrients differ from the average commercial diet in terms of digestibility?
DIGESTION = degradation process in GI tract:
Mechanical (teeth, stomach)
Chemical (stomach, small intestine)
Bacteriological (large intestine)
> Breakdown complex dietary substances
> create absorbable units
HIGHLY DIGESTIBLE = better proximal absorption, less overload distal:
-Digestibility:
Protein: >85% (comm. = 80)
Fat: >90% (comm. = 90)
NFE: >90% (comm. = 85)
Note: NFE = nitrogen free extract, proxy for carbs
factors influencing digestibility
- Ash
> (low = more digestible) - Fibre > Crude fibre <5% DM
> (more fiber = less digestible) - Anti-nutritive factors: trypsin inhibitor
(eg. in soy products) - Processing time/temperature > Maillard
(creates glycoproteins that are less digestible)
Animal source»_space; Plant sources
apparent vs true digestiility measurements
-manufacturers measure apparent > look at what is left in feces
-true would require inserting illial canula to look only at small intetstine, considered an unethical experiment
clinical applications of highly digestible diets
- Acute gastro-enteritis
- Small bowel disease
- Exocrine pancreatic insufficiency
- Pancreatitis
Also notable mention for:
- Colitis
- Constipation
signs of Exocrine pancreatic insufficiency
chronic diarrhea, polyphagia (2 X RER),
weight loss
- MCS: severe muscle loss
- Coat: dull, brittle
- Faeces: - Watery to semi-formed
- Clay-colored
- Large volumes
- Passed 2-3 times a day
in cases of Exocrine pancreatic insufficiency, what 3 M’s are occurring?
MALDIGESTION = unable to properly digest food due to pancreatic enzyme deficiency
leads to…
MALABSORPTION = unable to absorb undigested nutrients (e.g. intact proteins, fats, and carbohydrates)
MALASSIMILATION
reasons for bloating, flatulence, statorrhea and diarrhea in EPI
Undigested carbohydrates in the GIT
> bloating, flatulence, and diarrhea
Undigested fats
> steatorrhea and diarrhea
causes of small intestinal bacterial overgrowth
Loss of motility
Mechanic obstruction
Malassimilation > EPI
Local immunity
markers for SIBO
high folate, low cobalamine
consequences of SIBO
Toxins, hydroxy fatty acids, unconjugated bile acids > secretory diarrhea
Unconjugated bile acid:
- Less efficient micell formation
- Fat malassimilation
general approach for feeding a dog with EPI
highly digestible diet + enzymes
moderate fat restriction
low fiber generally,
- dietary fiber impairs pancreatic enzyme activity in vitro
?soluble vs insoluble?
why do we want to restict fat for a dog with EPI? how much restriction is needed? what important consideration needs to be made?
Reduces bile secretion
Fewer unconjugated bile acids/hydroxy-fatty acids
Secretory diarrhea ↓
Dietary fat levels:
- Moderate fat: 12-15% DM > Usually appropriate
- Severe restriction: <10% DM > Rarely necessary WITH ENZYME SUPPLEMENTATION
when we decrease dietary fat, we decrease caloric density substantially. EPI patients are in need of weight gain, so we must increase volume.
appropriate protein levels in food for EPI patient? what other considerations?
Moderate: 20 - 25% DM if good BCS/MCS
> IF Patients require weight gain (including lean body mass) then >30% DM
Highly digestible proteins
> Reduce protein available for bacterial growth (SIBO)
-eg.
Hydrolyzed Proteins
> Proteins that are already broken down (i.e. hydrolyzed) into smaller fragments, making them highly digestible.
should we supplement fat soluble vitamins ADEK for animals with EPI?
Vit ADE - depend on fat absorption
- supplement only if low levels, ongoing fat malabsorption, emaciated patient
- over-supplementation can cause problems!
- Vit K1
- If coagulopathies
> must inject!
Dietary supplementation:
- when disease responds to treatment
- when fat absorption is re-established
problems with vit B12 in EPI cases
Pancreas is not properly producing intrinsic factor. B12 must bind to intrinsic factor for absorption.
Development of VitB12 deficiency:
- Lack of intrinsic factor
Reduced VitB12 absorption in ileum
- Absence pancreatic HCO3
Decreased luminal pH
Reduced affinity for intrinsic factor - SIBO: VitB12 consumed by microflora in GIT
functions of vitamin B12
- Protein synthesis
- Red blood cell production
- Enzyme function in biochemical pathways
where is vit B12 stored?
- Liver UNUSUAL FOR WATER SOLUBLE VITAMINS
vit B12 deficiency leads to what conditions?
- Macrocytic anemia
- Poor growth
- Neuropathies
function of Vit B9
Enzyme function in biochemical pathways
how does SIBO affect folate (B9) levels? how to supplement?
Folate Excess:
Due to SIBO (antibiotics required)
-can also sometimes see deficiency if concurrent enteropathies
supplement per os
should we supplement dogs with EPI with raw pancreas? why?
no, risk of bacterial contamination
- used dried extracts instead
treatment and diet plan for dog with EPI
-high protein (37%) diet with fat 12-15% DM
Amount: 2 x RER based on idBW 34kg (to start)
-Adjust based on stool quality/quantity, BW, BCS, MCS
Frequent small meals
Pancreatic enzymes:
- 1 tsp, 3x/d, just before feeding
- Mixed with slightly moistened food
Parenteral fat-soluble & B-complex vitamins
over time, once ideal BW is reached, can reduce amount of food and pancreatic enzymes in absence of clinical signs
IMPORTANCE OF FAT in diets
- Energy source
- Source of essential fatty acids
- Vehicle of fat soluble vitamins
- Palatability
what signs do we often see if there is a disruption of fat digestion and absorption?
- Malassimilation: steatorrhea, weight loss
- Fatty acid, vitamin & mineral deficiency
- Secretory diarrhea
what is considered a moderate vs severe fat reduction in a diet? what is an important consideration when decided how much to restrict?
MODERATE REDUCTION
DOG: 12-15% DM
CAT: tolerate higher amounts (<23%DM)
SEVERE REDUCTION could be necessary DOG: <10% DM
Tolerate large food volumes?
e.g. pancreatitis + obesity / hyperlipidemia e.g. lymfangiectasia
consider DIET HISTORY
lymphagniectasia clinical signs
History: Watery diarrhea, flatulence
Good appetite, yet weight loss
Diet history: A lot of different diets, no succes
what is lymphangiectasia?
Obstruction of lymphactic system (primary, secondary)
Impaired lymphacticovenous flow
Lacteals distended with chyle
- Fat malabsorption
- Disruption of mucosal barrier
- Reflux of protein-rich lymph in lumen
- Hypoproteinemia
goals of feeding plan for lymphangiectasia
- Meet nutrient requirements
- Gain/maintain body weight
- Correct/prevent nutritional deficiencies
- Promote nutrient absorption
- Reduce enteric protein loss
key nutritional factors for foods for patients with lymphangiectasia/protein-losing enteropathy, and reasoning
Fat: Severe restriction (<10% DM)
> Minimise lymph flow
> Reduce lacteal & lymphatic distension
> Minimise protein loss
- Supplement Medium Chain Triglycerides oil (10-25% MER) if emaciated
theory behind feeding medium chain triglycerides to dogs with lymphangiectasia? contraindications?
- Hydrolyzed more rapidly in GI lumen
- Rely on small amount of intestinal lipase
- Absorbed in absence of bile acids
- Not re-esterified in enterocytes
- Primarily transported via portal vein?
APPLICATION:
Extra energy in emaciated patients 10-25% MER
Contraindication: liver pathology
diet choice for dog with lymphangiectasia
<10% DM fat
high protein for weight gain
small frequent meals
can supplement protein, MCT
how do we diagnose and treat food allergies in dogs
- Novel protein diets
- Hydrolyzed protein diets
typical signs of food allergy
Chronic intermittend diarrhea: 3-5 times a week
Fluid to semi-formed Occasional black
No tenesmus, no blood, no mucus Weight loss
Anorexia
feeding plan goals for dog with food allergies
- Meet nutrient requirements
- Maintain healthy body weight
- Correct/prevent nutritional deficiencies
- Promote nutrient absorption
- Reduce exposure to food allergens
key nutritional factors for hypoallergenic diet
FAT
Moderate: 12-15% DM
-MCT oil (10-25% MER) if emaciated
-N-3 fatty acid: reduce allergic & inflammatory reaction
Ratio: N-6:n-3 > 5:1 to 1:1
Dose: 50-100 mg EPA+DHA/kg BW
FIBRE
Low: Crude fibre < 5% DM
> Insoluble vs. soluble fibre: benefit from a little bit of soluble fiber
PROTEIN
Highly digestible Source:
- hydrolysed
- novel
Moderate: 20 - 25% DM
go >30% if weight gain required
can use short term supplement
what are novel proteins
Animal or vegetable ingredients containing proteins that are:
- Not commonly used in pet food and/or
- Not commonly associated with adverse food reactions
PRACTICALLY:
Avoid most common allergens
Max. 2 protein sources (animal + vegetable) to which animal has not been exposed before
DIET HISTORY!!
common food allergens in dogs and cats
beef
dairy
Particular attention: ingredients containing PROTEIN.
Molecular weight 10 – 70 kD
Stable to treatment with heat, acid, proteases
common novel proteins
venison
duck
rabbit
peas
lentils
……….
getting harder as more availability
what are hydrolyzed proteins? use in allergy treatmnet?
Enzymatic hydrolysis + ultrafiltration:
- Proteases: cleave protein into smaller peptides
- Ultrafiltration: removal of larger fragments
Smaller peptides / amino acids
> Lower molecular weight > Reduced allergenicity !
PREVENT:
- Clinical signs if sensitised to intact protein
- Sensitisation of naïve individual
influence of allergen size on reaction
Recommended < 10 kD, larger can bridge between 2 mast cells and cause degranulation (there are other mechanisms though)
BUT Average – very limited info
Infants <1kD > still allergic
elimination challenge steps
STEP 1:
Elimination of the responsible food
> Resolution of clinical signs
>GI disease 2-4 weeks!!
STEP 2:
Challenge with the original food
> Return of clinical signs within 3 - 7 days
> Elimination food
> Again alleviate clinical signs
STEP 3:
Provocation with single ingredients
> Return clinical signs?
purpose of fibre-enhanced diets
soluble fiber - prebiotics
PREBIOTICS
- Non-digestible food ingredients
- Selectively stimulate limited # bacteria
- Improve host health
possible positive effects of fibre enhanced diet
- Modifying gastric emptying
- Normalizing intestinal motility -
Buffering toxins - Binding excess water
- Maintaining normal GI flora
- Buffering gastric acid
- Altering viscosity – gel-like
possible negative effects of fibre enhanced diet
- Decrease DM digestibility
- Affect mineral availability
- Too high levels rapidly fermentable fibre: loose stool
- Too high levels of insoluble fibre: constipation
what happens to insoluble fibre after ingestion? what does it do for stool/food? application?
Small intestine: Escape enzymatic digestion Large intestine: Fermentation: extremely slowly
Adds non-digestible BULK
> Decreased energy density ↓
> DM digestibility ↓
Colonic distension
Stimulus for motility
APPLICATION:
- Colitis
- Constipation
what happens to soluble fibre upon digestion?
Small intestine: Escape enzymatic digestion
Large intestine: anaerobic bacteria > fermentation
effects of soluble fibre in the diet, and application
- Affect composition of GI flora
- Short chain fatty acids
- Intraluminal pH
- Water holding capacity and gel formation:
> Better consistency of ingesta
Application:
- Small / large bowel diseases
why does cude fibre for a food not tell the whole story? better measure?
only looks at cellulose, hemicellulose, lignin
>there are more fibre sources
Total dietary fiber is better - also includes soluble fibres
constipation diet reccomendation
-high water >75%
-crude fibre >7%
highly digestible
can high fibre help with megacolon? what should we do?
If motility patterns are completely abolished:
Fibre-enhanced diets / Fibre supplements
- No longer be effective stimulants of colonic motility
- Worse, can contribute to obstipation
Diet choice:
Highly digestible/low residue
Three different approaches for large bowel disease:
- Highly digestible, low residue GI diet
> Minimise amount of digesta entering colon - ‘Hypoallergenic’ diet
> Decrease potential antigens absorbed in the colon - High fibre diet
> Alter colonic motility
> Increase production of SCFA
> Maintain colonic pH > Control pathogen growth
> Water & electrolyte absorption - Or a combination
use for probiotics?
-in trial, reduced time to resolution of diarrhea
-but not really regulated….
