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

Student page

This unit is designed for creativity and art supplies will be needed to complete the corresponding activities that support understanding. The following student handouts should be printed out: Fecal Scoring Chart, History Exam, GI Project Tree Info Sheet.  The following are 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

• 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.

Lesson Background

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 whereas cats have sharp, pointed teeth designed for tearing meat.
2. Esophagus: 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 have stomachs that can hold large quantities of food whereas cats have smaller stomachs for smaller, frequent meals.
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 whereas cats have a shorter one.
5. Live & Pancreas: The liver produces bile which is needed for the digestion of fats. The pancrease 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 have a longer large intestine whereas cats have a much shorter large intestine.
7. Rectum & Anus: In both species’ the rectum and anuses function in the excretion of waste after digestion.

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. Diarrhea can form from increased transit time, decreased absorption of water, increased secretion of fluid, imbalances in the gut microbiome, dietary issues, infections, inflammation, parasites, stress, anxiety, toxins, poisons, or chronic conditions.

The clinical signs of diarrhea include loose or watery stool, increased frequency of defecation, straining to defecate, dehydration, abdominal discomfort or bloating, and in some cases, vomiting. 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.

In the veterinary medical field, even what seems like a simple case of diarrhea can become very complex. The point of the Diarrhea Decision Tree diagram is to show a simplified piece of what goes on during the diagnostic process and how veterinary professionals reach their diagnosis.

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.
• 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.
  • 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.

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.

Assessment

Students will work through a patient’s case to figure out the cause of diarrhea, using their new skills to diagnose and solve the patient’s problem.