The Difference Between Giardia & E. Coli in Dogs

Keep your pet healthy and avoid a belly ache.
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By simply looking at your dog you have no way of knowing if Giardia or Escherichia coli, E. coli, is causing his digestive or urinary discomfort. Also, while the symptoms associated with them may be similar, they may be associated with other, more serious, medical conditions as well. Therefore, immediate veterinarian care is necessary if your suspect your dog is suffering from either one.


Giardia is a parasite or protozoan encased in a protective cyst. Since it is a parasite, Giardia requires a host for survival. It can only live outside of the body for about 1 week in average temperatures. Once it enters your dog’s body, it lives and feeds off of him, causing giardiasis. E. coli, meanwhile, is a form of bacteria that often lives in the body of healthy adult dogs. Unlike Giardia, E. coli can live much longer. E.coli is often caused by food contamination or overgrowth of naturally occurring bacteria, according to the Dogged Health website.


When infected with Giardia or E. coli, dogs may show no symptoms at all according to the Centers for Disease Control and Prevention website. When symptoms are present, they include diarrhea, abdominal pain, gas and nausea or vomiting. E. coli may affect different parts of your dog’s body, including her digestive and urinary tracts. When infected, your dog may urinate more frequently, have a tender abdomen and experience bloody diarrhea. Also, when the infection is in her urinary tract, she may have bloody or dark urine with a foul odor.

Diagnosis and Treatment

Diagnosing both Giardia and E coli. requires a veterinarian. He generally takes a blood, urine or stool sample from your infected pet and performs a culture that helps your vet determine which one is causing your dog’s symptoms. After diagnosing either Giardia or E. coli, he often prescribes an antibiotic for treatment. If your dog is dehydrated due to the diarrhea, your vet may administer fluids intravenously. There is no over-the-counter treatment for either one, so vet care is required.


Dogs can be carriers of the Giardia protozoan and E. coli bacteria, so avoid large play areas where several dogs interact. If your dog is in contact with other dogs, do not let him drink from a community water bowl, since Giardia is often spread through contaminated water. Keep your pup’s living area clean. Remove any feces immediately, and clean his toys and bedding often. Feed your dog only fully cooked food.