Title

Got Diarrhea? Determining the Cause of Diarrhea in Dogs and Cats

Instructional guide

This unit is designed to help students work through potential causes for diarrhea by looking over a helpful decision tree. Students should be able to list common potential causes of diarrhea, how diarrhea is formed, and some potential clinical treatments that can be given to resolve the problem.

Student learning objectives

• Students should be able to explain what diarrhea is and how it occurs.
• Students should be able to determine poop scores based on fecal stool chart.
• Students should be able to list the main causes of diarrhea in both dogs and cats.
• Students should be able to trace the decision tree for the possible cause of diarrhea.
• Students should also know some possible treatments that can be given to help resolve diarrhea or treat symptoms.

Intended Grade Level

This lesson is intended for middle school students (6th to 8th grade). Prior to this lesson students should have already been introduced and have a basic understanding of the GI tract and how stool is formed. Students should also have been introduced to the concept of diarrhea.

Lesson Format

This unit is designed for creativity and art supplies will be needed to complete the corresponding activities that support understanding. Some handouts will need to be printed out for student participation to use during the activities. The handouts can also be used to complete the ending assessment of understanding. The evaluation of understanding will need to be completed individually on a computer. Space needed is a personal workspace with room to work on a computer and complete a hands-on craft (slime – so the space should be easy to clean).

The steps for the lesson are:

• The background knowledge (for teacher) will take approximately 1-2 hours to learn, review, and comprehend
• Teaching the whole lesson to students should take approximately 1-1.5 hour(s), the times are broken down into the pieces of the lesson below:
  • Review information should take around 5-10 minutes
  • The core material of the lesson should take 20-30 minutes
  • The matching activity should take around 5-10 minutes
    • A break for about 5-10 minutes can be included here to let the students get up and stretch before the next activity
  • The  slime activity should take approximately 15-20 minutes
  • The knowledge assessment should take approximately 5 minutes to complete
  • Questions at the end should be around 5-10 minutes based on time left.

Materials for the lesson are:

• Student handouts printed out
  • This will include the fecal score chart and the decision tree
    • Fecal Scoring Chart:
      • Fecal Scoring Chart
    • Diarrhea Decision Tree:
      • History Exam
    • GI Project Tree Info Sheet
• Art supplies if desired (these could include, markers/pens/pencils, scissors and potentially glue and craft paper) if students want to personalize their handouts
• Materials to make slime: large bottle of elmer’s glue, activator (contact solution), air dry clay, brown food coloring/dye, red food coloring/dye, yellow food coloring/dye, rice for parasites, beads for foreign objects, wax cooking paper to protect table surfaces, forks/spoons to help with mixing if a student does not want to use their hands, gloves if they would prefer that
• Computer with internet access to complete interactive portion of the lesson and the knowledge assessment

Lesson Background

Dog and Cat Gastrointestinal System

The gastrointestinal (GI) system of dogs and cats is responsible for the digestion and absorption of nutrients form food. Both species share many similarities but there are key differences that arise from their dietary habits – dogs are omnivores while cats are obligate carnivores.

1. Mouth & Teeth
   • Dogs: have a mix of sharp teeth for tearing meat and flatter teeth for grinding plant material
   • Cats: have sharp pointed teeth designed for tearing meat
2. Esophagus
   • Dogs and Cats: Responsible for moving food from the mouth to the stomach through peristaltic (wave-like) contractions.
3. Stomach
   • The stomach is the main organ for protein digestion and absorption of some nutrients. The stomach is highly acidic to facilitate the breakdown of proteins and to kill harmful bacteria in food.
   • Dogs: pH ranging from 1.5-2.0 which is acidic enough for digesting protein and some fats. Their stomachs can hold large quantities of food allowing them to eat large meals during one sitting.
   • Cats: Their stomach is typically smaller making them more adapted to eating smaller frequent meals which is inline with their natural hunting behavior.
4. Small Intestine
   • This is the location where most nutrient absorption occurs and it has three parts: the duodenum, jejunum, and the ileum.
   • Dogs: Have a longer small intestine which is adapted for digesting both animal protein and plant material. Enzymes like amylase, lipase, and proteases break down carbohydrates, fats, and proteins.
   • Cats: Have a shorter small intestine. Cats primarily rely on protein and fat for nutrition so the small intestine is optimized for the absorption of amino acids, fatty acids, and other nutrients found in animal tissues.
5. Live & Pancreas
   • Liver: produces bile which is needed for the digestion of fats
   • Pancreas: secretes digestive enzymes (amylase, lipase, and protease) into the small intestine to aid in the digestion of fats, carbohydrates, and proteins.
6. Large Intestine
   • The large intestine is involved in the absorption of water and electrolytes along with the formation of feces. It houses the microbiome that helps with fermentation and further break down of undigested food material.
   • Dogs: They have longer large intestines to help them extract nutrients from plant material.
   • Cats: They have a much shorter large intestine so their digestive system is more efficient at absorbing water and nutrients, leaving little to ferment or break down in the colon.
7. Rectum & Anus
   • In both species’ the rectum and anuses function in the excretion of waste after digestion.
   • Both species will excrete feces that contain undigested material, like fiber, as well as waste products from metabolic processes.

Normal Fecal Formation & Diarrhea 

Diarrhea in dogs and cats occurs when there is an abnormality in the digestive system that leads to rapid movement of food through the GI tract. Several Factors can contribute to diarrhea in pets and understanding how it forms involves looking at changes in the normal digestive process.

How diarrhea forms in dogs and cats:

1. Increased Transit Time: if food moves too quickly through the GI tract there is less time for water absorption in the intestines
   • Causes: inflammation, infection, or irritation
2. Decreased Absorption of Water: the small intestine and colon are responsible for absorbing water and electrolytes and if there are any issues in either the small intestine or the colon they can’t effectively absorb water
   • Causes: infections, parasites, inflammatory bowel disease
3. Increased Secretion of Fluid: sometimes the intestines may secrete excessive amounts of fluid into the gut in response to infection, toxins or diseases
   • Causes: infections, viruses, parasites
4. Imbalance of Gut Flora (microbiome): the gut microbiome is made up of bacteria that helps break down food and disruption of the flora can cause diarrhea
   • Causes: antibiotic treatment, changes in diet, stress
5. Dietary: certain foods or food changes can irritate the GI tract
   • Causes: sudden diet change, rich or fatty foods, food intolerances, garbage, toxic substances
6. Infection & Inflammation: infections can damage the intestinal lining and disrupt normal digestion and absorption
   • Causes: viruses, bacterial infections, inflammation, fluid secretion
7. Parasites: internal and external parasites can cause diarrhea by either causing irritation in the intestines or disrupting nutrient absorption
   • Causes: giardia, hookworms, roundworms, or coccidia (just some parasite examples)
8. Stress or Anxiety: can effect the GI system
   • Causes: emotional stress can trigger changes in the gut’s normal function
9. Toxins or Poisons: if a a pet ingests something toxic it can irritate or damage the GI tract
   • Causes: ingestion of toxic substances can lead to an overproduction of fluids in the intestines or cause inflammation that disrupts the GI tract
10. Chronic Conditions: inflammatory bowel disease or cancer can lead to persistent diarrhea
    • Causes: the intestines are chronically inflamed impairing nutrient absorption and causing diarrhea, tumors may obstruct normal digestion and lead to watery stools

Clinical Sings of Diarrhea 

• Loose or watery stool
• Increased frequency of defecation
• Straining to defecate
  • Not due to being unable to defecate but because they feel like they have go even if there isn’t anything there
• Vomiting (some cases)
• Dehydration
  • Severe diarrhea can lead to fluid loss
• Abdominal discomfort or bloating

Diarrhea Decision Tree

In the veterinary medical field, even what seems like a simple case of diarrhea can become very complex. The point of this diagram is to show a simplified piece of what goes on during the diagnostic process and how veterinary professionals reach their diagnosis. Below is an information key to help understanding while working through the steps. Walk through one of the practice questions with the students and then let them try with their own diarrhea tree diagram.

Some practice questions include…

1. An 4 year old male Dalmatian has has diarrhea twice today. What test would we run?
2. An 8 year old female greyhound has been having diarrhea consistently for 3 weeks. We ran the first four tests and we still don’t know what caused the diarrhea. What other tests could we run?

GI Project Tree Info Sheet

When to Seek Veterinary Help

If diarrhea persists from more than 24-48 hours, or if it is accompanied by other symptoms like vomiting, lethargy, or if there are signs of dehydration. Seek emergency medical care if a known toxin or foreign body (like a sock) is ingested.

Activities

• Digital matching activity: this will lead students through matching items that might cause diarrhea and being able to differentiate between things that are regular food items for dogs and cats and should not cause any issues.
  • This activity will require internet access but should not take any more than 5-10 minutes and is a great introductory topic to what dogs and cats should and shout not be eating.
  • Some questions might have to be answered when the students get things wrong and at the end of the activity an overall summary should be given of why certain items cause diarrhea and others do not.
• Slime activity: This activity is a fun engaging activity for middle school age students to be able to be able to go through the process of making slime. This should take 15-20 minutes. We are going to need the below supplies:
  • Materials to make slime: large bottle of elmer’s glue, activator (contact solution), air dry clay, brown food coloring/dye, red food coloring/dye, yellow food coloring/dye, rice for parasites, beads for foreign objects, wax cooking paper to protect table surfaces, forks/spoons to help with mixing if a student does not want to use their hands, gloves if they would prefer that
  • As we lead the students through the activity it is overall the process of making slime:
    • Make sure sheets of wax paper have been put down on each student’s desk to protect desk surfaces and allow for easy cleanup.
    • Dole out a large dollop of glue onto each student’s wax paper
    • Add different colors to show the variety of stool colors that can be possible.
      • You can randomly select students to have different issues that cause diarrhea:
        • Gastroenteritis you can add drops of frank blood or red flood coloring to mix in
        • Pancreatitis you can add yellow food coloring
        • Parasites you can add rice to simulate parasite eggs
        • Foreign bodies you can add beads
      • To simulate how diarrhea is made which accounts for how much water is absorbed during the passage through the intestinal tract you can have students add more and more contact solution and see how that affects the consistency of the slime.
        • What you should see is that initially as you add contact solution or activator and start kneading you start to get a good slime consistency that starts to stick together. As you add a lump of air dry clay you get something that becomes even more solid and formed. However, as you add our different issues (red food coloring, yellow food coloring, rice, beads, etc) and more contact solution–the more you start kneading the less form we start having. Overall the slime starts to break down as more fluid is added and we are unable to pick it up cleanly anymore which simulates diarrhea.
    • This is a fun activity for kids because slime is a very hot item right now and we are able to weave in some learning while getting the kids engaged in making slime.
  • Assessment
    • See student page

Common misconceptions and challenge points

• Nutrient absorption is done throughout the whole GI system equally
  • 90-95% of nutrient absorption is done the small intestine
  • There is no nutrient absorption after the colon
• Diarrhea is always dangerous
  • Serious underlying conditions can cause diarrhea but more often than not it is caused by something simple like ingesting human food and will potentially resolve on its own.
• Diarrhea is only a sign of a gut issue
  • This lesson covers many causes of diarrhea and many of them are not connected to gut issues
• Blood in stool always means something serious
  • Fresh blood is usually not a huge concern and is often caused by inflammation or straining. Darker-colored blood or black stools may indicate bleeding from the upper GI tract and require diagnostic tests.
• Dog and Cat GI systems can digest the same things
  • Dogs are omnivores and have a versatile GI system that can digest a wilder range of plant and animal materials. Cats are obligate carnivores with a highly specialized system for breaking down protein and fat.