Giardia

Keeping with the theme of water safety according to the CDC top 5 causes of drinking water outbreaks are: 

1. Giardia
2. Shigella
3. Norovirus
4. Hepatitis A
5. Copper

What is Giardiasis?


Giardiasis is a diarrheal disease caused by a protozoan parasite Giardia that is infectious to both humans and pets.  Giardiasis usually affects dogs, particularly puppies, but can occur in cats.  It's not so much that Giardia is passed directly from animals to humans, but both come into contact with the same contaminiated water source.  Many dogs pick it up from puddles at the dog park (which is why I'm always telling Dreyfus not to drink from the puddles!).  People get giardia by drinking contaminated water or ice, swallowing water while swimming, eating uncooked food that’s contaminated.   


Once a person or animal has been infected the parasite lives in the intestine and is passed in feces.




Clinical signs


Most common clinical sign in both dogs and humans is diarrhea, which can be either mild or severe.  Other symptoms include gas, nausea/vomiting, abdominal cramps and dehydration. In dogs usually the diarrhea goes away on its own and the pet is fine, but severe cases can cause weight loss and general lethargy.  In people symptoms can last 2 to 6 weeks.


Contact your health car provider if you think you or your pet may have giardiasis.


Diagnosis


The infection is diagnosed with a fecal examination.




Treatment 


Treatment in dogs with typically includes metronidazole and a broad spectrum dewormer called fenbendazole.  If the pet is severely dehydrated from the diarrhea, fluid therapy may be necessary.  Most pets don’t become seriously ill because of Giardia, so the prognosis is almost always good. However, if the pet has an underlying disease giardiasis can cause a more serious infection.  However, even these animals typically recover with slightly more intensive treatment.


In people there are many prescription drugs available to treat giardiasis please contact you physician. 


Prevention

• Good hygiene – hand washing
• Avoid drinking water that may be contaminated 
• Use a water purification method such as boiling, filtration, or iodine treatment before drinking surface water
• Avoid eating food that may be contaminated
• Prevent contact with contaminated feces

Environmental and Dog Decontamination

I do recommend environmental decontamination for any dog that has been infected with giardia.  The most effective disinfectant is bleach diluted 1:32 in water which required less than one minute of contact time to kill Giardia cysts.  

If your dog does become infected, it is important for your pet to be bathed at the completion of treatment and retested to minimize the potential for reinfection of the pet and of the humans in the house.  Once again good hygiene, such as washing one's hands after handling the infected pet or its waste and prompt disposal of feces, is the key to prevention. 

Dog vaccine?

 A Giardia vaccine is on the market but not to prevent infection.  Instead to be used as an adjunct to treatment and reduce the shedding of cysts.

The 2006 American Animal Hospital Association Guidelines list this vaccine as not recommended.