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Cause and Symptoms | Diagnosis and Treatment | Giardia and Humans
As summer approaches, our thoughts turn to the great outdoors. The beautiful mountains, lakes and streams of the Colorado Front Range are a perfect playground for hiking, camping, boating and just plain relaxing! For many of us, these activities are enhanced by having our dogs at our side, sharing in the joy of the wilderness.
Unfortunately, as our time outdoors increases, so does the risk of Giardia infection for our dogs. Giardia is a water-borne parasite that is widespread along the Front Range. If a dog ingests the Giardia cysts (commonly found in lakes, streams, ponds, drainage ditches or other sources of standing water) the organisms may attach themselves to the small intestine and cause an intestinal upset. Signs of Giardia may be large quantities of greasy, mucousy stools and, occasionally, vomiting, lethargy and decreased appetite. These signs may come on suddenly, or be chronic or intermittent.
It is also possible for a dog to be infected with the Giardia cysts but have no signs of the disease. It is thought that many dogs in Larimer County may be part of this "carrier" group, and never get sick or show signs at all. Cats are also potential victims of Giardia, especially those that spend a lot of time outside.
Giardia is diagnosed by visualizing the cysts microscopically on a float or direct smear of fecal material. A heavy infestation may be fairly easily diagnosed, however, if the pet is not actively shedding the cysts at the time of the fecal exam, the cysts may be "missed" on a single sample.
Treatment of Giardia is meant to achieve two goals. The first goal is to decrease the signs of illness and make the pet feel better. The second goal is to decrease the chance of shedding the Giardia cyst into the environment via the feces. Treatment has traditionally consisted of a tablet called Metronidazole (common name "Flagyl"), which is designed to rid the intestine of the Giardia cysts. This medication, although the best we have available, is only successful in approximately 65% of dogs. It also has the added disadvantage of tasting really bad, so it is not always easy to medicate cats.
Recently, a vaccine has also been developed to help control Giardia. The vaccine does not prevent the pet from getting Giardia, nor does it "cure" Giardia or eliminate all the cysts. What it does do, is help decrease the clinical signs seen with Giardia and decrease the amount of cysts shed in the feces. The vaccine may also be used in combination with Metronidazole to help try to speed the recovery of pets already infected.
Finally, it is important to note that Giardia is one of the most common intestinal parasites in humans in North America. Signs of Giardia in humans are similar to those in pets, and can be quite severe (especially in the very young, very old, or immuno-compromised individual). The transmission of Giardia from dogs and cats to humans is poorly understood, so it is wise to use caution "just in case". Keeping the yard clean, washing hands before eating and keeping an eye on what small children put into their mouths are all wise choices to help decrease the risk of Giardia infection. It is also wise to carry your own drinking water when hiking or camping in the mountains, since many of our Rocky Mountain streams and lakes may potentially carry Giardia. You may also choose to have your pet vaccinated.
So…enjoy the summer, enjoy the beauty of the outdoors, and enjoy your pets!! And, if you have any questions about Giardia (or anything else!) feel free to give us a call.