NUTRITIONFood and Digestion: A Case Study

Objectives• Case study introduction• Develop an educational foundation in both digestion and

nutrition• Apply new knowledge in discussion of case study

CASE STUDY: Max• Signalment-

• 6 months old• Intact male• Yellow Labrador Retriever

• Chief Complaint- • Vomiting and diarrhea

• Physical Exam-• Lethargy/fatigue• Dysentery• Dehydration

CASE STUDY: Max

• History of present illness-• Started having diarrhea

yesterday morning and hasn’t stopped (~6x daily)

• Diarrhea appears mucoid and bloody

• He is potty trained but is pooping in the house anyways

• Began vomiting a few hours after first diarrhea spotted

• Vomit is clear, like water

• He has not been interested in playing with his toys, even his favorite stuffed bunny

• Stopped drinking or eating

• Only pet in the home

• Inside/outside dog

NUTRITIONA Foundation

Nutrition: Pregnancy and Early Childhood

• Physical and mental growth and development will be impaired if malnourished during:• Pregnancy• First two years of life

• This damage cannot be remedied once the child has aged• It will permanently affect the child

Nutrition: A Balanced Diet• Proteins: source of materials for growth and repair.

• Carbohydrates: source of energy.

• Fats: source of energy and contain fat soluble vitamins.

• Vitamins: needed for many enzyme systems.

• Minerals: needed for healthy teeth, bones, muscles etc.

• Fiber: helps your intestines function correctly; it is not digested.

Nutrition: Protein• A little protein chemistry:

• Proteins are large molecules made up of combinations of amino acids.

• Amino acids are organic substances made of nitrogen, oxygen, hydrogen and carbon.

• Some proteins additionally contain Sulfur (S) or Iron (Fe).

• Proteins are 3D structures • Folding is dependent on amino

acids present and the environment the protein is in

• Folding may also depend on a protease that cuts the protein or a ligand binding to the protein

Nutrition: Protein

Nutrition: Protein• Mad Cow Disease

• AKA Bovine Spongiform Encephalopathy (BSE)• PRION Disease

• Caused by misfolding of a necessary protein made in the nervous system• Acquired both randomly through mutation and by eating an already misfolded protein (contaminated

food)• A “bad protein” can misfold already present “good proteins” so that they are also bad.

A bad influence persuades the good kids to also be bad• The bad kid can move in from far away• The bad kid can develop randomly from a good kid

• BSE in the United Kingdom peaked in January 1993 at almost 1,000 new cases per week• Cumulatively, through the end of 2010, more than 184,500 cases of BSE had been confirmed in the

United Kingdom alone in more than 35,000 herds

• Other prion diseases:• Scrapie – Sheep• Creutzfeldt-Jakob – Humans• Kuru – Humans• Chronic Wasting Disease – Ruminants (deer, elk, etc)

Nutrition: Protein

PrPc= Normal protein

PrPsc= mutated or acquired bad prion

Nutrition: ProteinProtein content in grams per 1 cup:

Beef Sirloin 68.8Chicken Breast 43.3Salmon 40Cheddar Cheese 32.9Eggs 24.4Soybeans 22Almonds 20.2Beans, Pinto 15Peas, black-eyed 13Beans, red kidney 13Beans, baked 13Peas 8Spinach 6

Corn 5Rice 5Veggie burger 5Peanut butter 4Noodles 3.7Potatoes 3.5Beans, green 1.6Cauliflower 2Cabbage 1.5Carrots 1Cucumber 0.7Lettuce 0.7Mushrooms 0.3

All meats are high in protein!

Nutrition: Carbohydrates

• Some carbohydrate chemistry:• Carbohydrates are organic substances made of Carbon, Hydrogen

and Oxygen.• Carbohydrates are also called “sugars” and “starches.”• Carbohydrates are used in our bodies for energy. • These are broken down in the GI tract into maltose and glucose

Fruits, breads, pastas, beans, potatoes, bran, rice, and cereals.

Nutrition: Carbohydrates• Monosaccharides

• The most basic units of carbohydrates. They are the simplest form of sugar and are usually colorless, water-soluble, crystalline solids.

• Fructose- aka “fruit sugar”• Glucose- form of sugar used in the body as

energy; all other sugars and carbohydrates will be converted into glucose in the digestive system

• Galactose- from mammals’ milk

• Disaccharides• A sugar (a carbohydrate) composed of two

monosaccharides. It is formed when two sugars are joined together and a molecule of water is removed.

• Sucrose- Glucose + Fructose• Lactose- Glucose + Galactose• Maltose- Glucose + Glucose

Hexose HexosePentose

• Oligosaccharides• A sugar composed of 3-10

monosaccharides attached together

• Polysaccharides• A sugar that consists of polymers of

chains (in some cases very long chains) of monosaccharide or disaccharide units all joined together.

• Starch- long chains of glucose formed by plants in photosynthesis

• Cellulose- long chains of glucose that are indigestible by humans; Serve as fiber in diet

• Glycogen- long chains of glucose formed by the human body to store glucose for future energy when it is in excess

Nutrition: Carbohydrates

Nutrition: Fats• Fats are organic molecules

made of Carbon, Hydrogen, and Oxygen.

• Saturated fats = unhealthy• Have only single bonds

between carbons• One carboxylic acid group• linked to cardiovascular disease

and several types of cancers

• Unsaturated fats = healthy• Have one or more double bonds

between carbons• One carboxylic acid group • lower your risk of heart disease

by reducing the total cholesterol

Healthy (unsaturated) • Sources of these fats include

vegetable oils, fish, nuts, seeds, olive oil and avocados.

• These fats are typically liquid at room temperature

Nutrition: FatsUnhealthy (saturated)• Sources of these fats include

dairy products, animal fats and oils like coconut oil, cottonseed oil and palm kernel oil.

• These fats are typically solid at room temperature

Compare the two types of

fats. What is the

difference?

A double cheeseburger can have 35g of

saturated fat! That is almost twice the maximum daily

amount suggested!

Nutrition: Fats

• Fun fact- you can always make adipocytes, but you cannot ever kill them

• When you “burn fat” you are actually releasing the triacylglycerides into the blood stream as free fatty acids to be used as energy, effectively shrinking the size of the adipocyte

• Fat cell= Adipocyte

• Free Fatty Acids are consumed and absorbed within the GI tract

• These will be packaged onto glycerols to form units called triacylglycerides

• Triacylglycerides are stored within adipocytes

Nutrition: Fats• Diabetes

• Two types• Type 1- genetic autoimmune disease

• Unable to produce insulin

• Type 2- acquired• Does not produce enough insulin

OR

• Has insulin resistance

• Fat can play a large role in the onset of Type 2 diabetes• Adipocytes secrete adipokines • Adipokines are hormones that impair blood-glucose tolerance which will

lead to insulin resistance• To prevent or reverse Type 2 diabetes, often the patient just needs to

eat right and exercise to shrink the adipocytes causing the problem

Nutrition: Vitamins and Minerals• Vitamins:

• Fat soluble-• A, D, E, & K

• Water soluble-• B-complex & C

• Minerals: • Major-

• Sodium, Potassium, Calcium, Phosphorus, Magnesium, Manganese, Sulphur, Cobalt, and Chlorine

• Trace-• Iron, Zinc, Copper, Selenium,

Iodine, Fluorine, and Chromium

DIGESTIONA Foundation

Mouth & Esophagus• Mouth:

• Chewing• Teeth• Saliva from salivary

glands• Bicarbonate• Amylase

• Swallowing• Esophagus:

• Muscular tube that moves food into the stomach

Stomach• Releases acids and

enzymes which break down food further• Gastrin• Secretin• H+, Cl-

• Muscular contractions mix and degrade food• Chyme!

• Thick mucus layer protects against low (acidic) pH.

Small Intestine• Entry point of bile from

gallbladder• Bicarbonate• Emulsification of fat

• Entry point of pancreatic enzymes• Trypsin- protein digestion• Lipase- fat digestion• Amylase- carbohydrate digestion

• Villi and microvilli allow reabsorption of fluids and nutrients from chyme• Primary site of nutrient

absorption

Small Intestine• Major site of mucoid/bloody diarrhea

• Loss of villi/microvilli that line the walls • Lack of reabsorption of water due to mineral

shifts

Small Intestine

Large Intestine

• Reabsorbs more fluids to condense the chyme into feces

• Major site of secretory diarrhea• Lack of reabsorption of water due

to mineral shifts can cause diarrhea

• Loss of microvilli that line the walls can also cause diarrhea

Large Intestine

Large Intestine

Exit

• Ewww… GROSS?!• But very important in monitoring health in you and your

pets

CASE STUDYA Discussion

CASE STUDY: Max• Signalment-

• 6 months old• Intact male• Yellow Labrador Retriever

• Chief Complaint- • Vomiting and diarrhea

• Physical Exam-• Lethargy/fatigue• Dysentery• Dehydration

CASE STUDY: Max

• History of present illness-• Started having diarrhea

yesterday morning and hasn’t stopped (~6x daily)

• Diarrhea appears mucoid and bloody

• He is potty trained but is pooping in the house anyways

• Began vomiting a few hours after first diarrhea spotted

• Vomit is clear, like water

• He has not been interested in playing with his toys, even his favorite stuffed bunny

• Stopped drinking or eating

• Only pet in the home

• Inside/outside dog

CASE STUDY: Max• Differential Diagnoses:

• Canine parvovirus• Canine distemper• Infectious canine hepatitis• Canine coronavirus• Septicemia:

• Salmonellosis• Campylobacteriosis

• Haemorrhagic gastro-enteritis• Poisonings

Actual Diagnosis: Canine Parvovirus

Canine Parvovirus

• Virus

• Causes gastroenteritis

• Transmitted fecal-orally and through inhalation

• Very difficult to clean/kill• Bleach in a 1:32 dilution solution• Lives in environment for a very long time

Canine Parvovirus

• Pathogenesis: • Virus infects mature cells covering the

upper two-thirds of small intestine villi• This will cause sloughing of dead

mature cells which effectively blunts the villi

• Small intestine can no longer absorb nutrients

• Diarrhea and vomiting results• Dehydration and malnutrition follows• Death is common

Canine Parvovirus

• Pathogenesis: • Virus infects mature cells covering the

upper two-thirds of small intestine villi• This will cause sloughing of dead

mature cells which effectively blunts the villi

• Small intestine can no longer absorb nutrients

• Diarrhea and vomiting results• Dehydration and malnutrition follows• Death is common

Canine Parvovirus

• Pathogenesis: • Virus infects mature cells covering the

upper two-thirds of small intestine villi• This will cause sloughing of dead

mature cells which effectively blunts the villi

• Small intestine can no longer absorb nutrients

• Diarrhea and vomiting results• Dehydration and malnutrition follows• Death is common

CASE STUDY: Treating Max• To keep Max from getting further dehydrated, we will treat

him with an anti-emetic called Metoclopramide

• If Max weighs 14 lbs and the recommended dosage is 35 mg/kg for Metoclopramide with a drug concentration of 20 mg/mL, how many mL of drug should you administer to Max?• Hint: 1kg = 2.2 lbs

QUESTIONS?