Giardia are protozoa that prey on the small intestines of animals including young puppies and older dogs. They are transmitted when your dog comes into contact (direct or indirect) with infected feces. This most often happens by drinking compromised water but can also happen by grooming after contact with feces that contain Giardia cysts. The best ways you can protect your dog from this parasite are to provide him with safe drinking water and to keep him away from the feces of unknown dogs in dog parks and other public places.
The resulting infection of contact with Giardia is called giardiasis and is often asymptomatic. But when it does show, it can cause diarrhea and sometimes weight loss. An infected dog's feces may be lighter in color, have an abnormally funky odor and look somewhat greasy. We'll watch out for that for you and alert you as soon as we discover any warning signs. And we will also be happy to bag a fecal sample for you to take to your veterinarian for diagnosis and treatment options.
For more information on Giardia we suggest visiting Pet Education's thorough article on the subject. And as we learn more we'll be sure to continue sharing!