After being ingested from drinking feces contaminated water, or from a contaminated surface, giardia in dogs colonize and multiple in the small intestine . Because of this, the protozoa interfere with digestive function. This results in a range of issues such as a reduction in the body’s ability to absorb nutrients from food (malabsorption), problems with digestion (maldigestion) and a problem called hypermotility (which means excessive bowel movements).
Dog Giardia Incubation Period
Clinical dog giardia symptoms will begin to appear in 5 to 14 days.
Giardia Symptoms in Dogs
In terms of clinical giardia symptoms in dogs (also referred to as giardiasis), which are symptoms that you can observe or see, the primary symptom is moderate to severe diarrhea that seems to persist without going away (intermittent). In dogs with diarrhea, approximately 15% of cases are thought to be caused by dog giardiasis.
Other dog giardia symptoms can include:
- soft stools that are light in color and often contain mucus (from undigested fats)
- poor hair/coat
- lethargy or weakness
- decline in overall condition
- weight loss or an inability to gain weight
- death (severe cases)
Some of these symptoms such as weight loss and lethargy are amplified by the body’s loss of fluids/dehydration due to the diarrhea.
Symptoms such as blood in the dog stool (hemorrhage, blood is very rare) and or a black dog stool with a tar like consistency (melena) are not associated with condition and could indicate another underlying cause of the problem.
Most dogs with giardia will be asymptomatic, meaning that they will show no visible symptoms. These dogs will still shed the giardia in protective cysts through the feces, creating a hazard for dogs that are vulnerable to clinical symptoms such as puppies and older dogs with weakened immune systems.
References on Giardia Symptoms in Dogs:
Giardiasis in Dogs and Cats: Diagnosis, Treatment, and Zoonotic Risk (2010)
Susan E. Little, DVM, PhD, Dipl. EVPC
Center for Veterinary Health Sciences
Oklahoma State University, Stillwater, OK, USA
Carlin EP, Bowman DD, Scarlett JM, et al., 2006. Prevalence of Giardia in symptomatic dogs
and cats throughout the United States as determined by the IDEXX SNAP Giardia test. Vet
Companion Animal Parasite Council Guidelines, Giardia. CAPVET Accessed
May 1, 2010