Giardia in dogs

 

Tell your veterinarian if your
dog regularly dives into ponds

MetPet.com Staff Writer

It
is
hot, the pond or river or lake looks terribly inviting but take some
precautions before letting your dog go swimming in untreated water.   
Make sure you have your dog’s Giardia vaccination up to date. 

Giardia is a one-celled protozoal
parasite that causes giardiasis.  In humans, it is one of the
most common protozoan water borne illnesses although it is unknown
if the species of Giardia that infects humans is the same as that
which infects dogs, cats and other animals. 

Dogs ingest the Giardia cyst most likely through drinking
contaminated water.  Since the parasite can live outside of
hosts possibly for months, it may also be transmitted from infected
fur, lawns, kennels, etc.  In the small intestine, the cyst
opens into a trophozoite that attaches to the intestinal wall and
reproduces through division.  At some point in its lifecycle,
the parasite then becomes a cyst again and passes through the feces
ready to be ingested by another host. 

Giardia prevents absorption of
nutrients in the intestine interfering with proper digestion. 
The result commonly includes diarrhea, loss of weight and possible
loss of appetite.  Diarrhea can be caused by any number of
bacteria or other causes and Giardia cysts are difficult to detect
in feces (take several samples over several days since cysts are not
always being shed) so it is not always possible to pinpoint Giardia
as the cause of symptoms. 

There is much that is unknown about this parasite including how
common it is, how often infection leads to disease, whether it can
be passed between humans and animals or even all of the details
about its lifecycle.   It is a good idea, therefore, to
err on the side of caution particularly with young dogs, older dogs
and those with compromised immune systems. 

Treatment includes the use of one
or a combination of different drugs some of which have been approved
for use in dogs for other intestinal parasites and some which have
not.  Efficacy is questionable as the parasite may still be
present in the intestines even though cysts cannot be detected in
the feces. 

In general, prevention is the best
idea.  A vaccine,
GiardiaVax from Wyeth
is available from your veterinarian.

Another alternative is to maintain
your dog’s hygiene, avoid untreated water and areas of possible
contamination such as parks and kennels.