How Does Bacteria Cause Diarrhea in Pets?

Pets can get bacterial diarrhea by eating spoiled food.

Pets normally have different kinds of bacteria living in their intestinal tracts. These are beneficial and aid in digestion. Diarrhea occurs when pathogenic bacteria gain access to the intestines.

Kinds of Pathogens

Bacteria that can cause diarrhea in the small intestine include Salmonella, Clostridia, Escherichia coli, Staphylococcus or Campylobacter.

Symptoms

Bacterial diarrhea is usually characterized by a stool frequency of three to five times a day, with a fair amount of liquid-like stool. Flatulence may also occur.

Mode of Entry

Escherichia coli and Staphylococcus can occur in spoiled food. Campylobacter and Salmonella are obtained from improperly cooked food.

Bacterial Adherence

When a disease-causing bacterium enters the intestine, it first adheres to the intestinal wall. It can then secrete toxins, invade cells and multiply.

Toxins

Bacteria produce two types of toxins. Enterotoxins act on the intestinal wall, causing fluid leakage and watery stools, without harming the intestinal cells. Cytotoxins damage the cells and prevent absorption of water and nutrients.

Invasiveness

Some bacteria can enter the intestinal wall cells and multiply there, causing lesions and bloody diarrhea with pus.

References

• Washington State University College of Veterinary Medicine: Pet Health Topics - Diarrhea
• Springer Link: Pathogenesis and Diagnosis of Bacterial Diarrhea
• 2nd Chance: Why Does My Dog or Cat Have Diarrhea?