2013年9月16日星期一

Causes of Giardia in Dogs Symptoms Diagnosis and Treatment


“Contaminated water is one of the causes of giardia in dogs as well as general exposure in the environment such as exposure to contaminated surfaces in parks or even the dog’s food if that also becomes contaminated. The disease is caused by protozoa that are encased in a protective cyst that cannot be seen by the naked eye. The dog then ingests thesecysts, allowing one of three things to happen. Either the dog’s immune system will eliminate the protozoan from the body, or theprotozoaenter and multiply in the dog’s small intestine, allowing them to reproduce causing cysts to be shed in the dog’s feces, which can then infect other dogs. Most dogs show no symptoms (asymptomatic), but in those that do, symptoms develop in later states of the disease as the protozoa colonize in the intestines, feeding off the dog and preventing nutrients from being absorbed in to the body. The most common symptom of giardia in dogs is loose, but not watery diarrhea which is characterized by a foul odor and mucus. The dog diarrhea is often frequent and urgent. Other symptoms include gas, poor coat quality and vomiting. As the disease develops a dog will show weight loss and lethargy. Only a veterinarian can diagnose the problem. Treatment involves the use of prescription medications that help to combat parasites. Adding fiber to the diet and supportive Herbal remedies can help speed recovery. If not treated ,a dog can remain infected indefinitely. The dog’s home needs to be decontaminated with bleach.It is possible for giardia to be transmitted from dog to human, although this is uncommon, so use care when handling an infected pet.”



The most common causes of giardia in dogs is drinking from a
lake, pond or
stream that is contaminated with infected animal feces. The feces
contains a cyst or small sac
that enters the gastrointestinal tract of the dog.  The cysts
protect or encase Trophozoites which actually cause the condition.


causes of giardia in dogs
Causes of Giardia in Dogs
are protozoa passed in the form of a cyst that are ingested by dogs
from feces in either contaminated water or when ingested
from the environment such as a
dog run or kennel.

Source: Centers
for Disease Control



The protozoa  divide in two rapidly and expand in number as
they feed on and take away nutrients from your
dog. The protozoa also produce harmful substances. Left untreated,
Giardia can damage the lining of the small intestine and cause scaring.
 Some of the Trophozoites will form new cysts, which pass out
of or are shed from the body, allowing the disease to spread.



The disease is sometimes called Beaver Fever since beavers are known
carriers of giardia. These are also the most commonly diagnosed
protozoa in humans.


Coccidia
is a similar parasite that affects the intestinal tract. Unlike the
causes of giardia in dogs from lakes and streams, coccidiosis is
contracted by eating feces directly.


Approximately 15% of dogs that have diarrhea and/or vomiting
suffer
from giardia.  In areas where there giardia is commonly found
(such as
areas with natural lakes and other waterways), approximately 6% to 11%
of dogs shed giardia cysts.  Shedding of giardia cysts is more
common in dogs under three years of age.


Symptoms of Giardia in Dogs


Giardia interferes with the absorption of nutrients from food.
As can be expected, when you don’t get the nutrients you need, you lose
weight and appear to have less energy.



Dogs with giardiasis may have no symptoms, as is the case in most dogs,
or diarrhea and vomiting.  In the majority of cases, blood is
not found in the dog’s feces. Diarrhea tends to
be bad smelling and very watery. Diarrhea may be bad or light and occur
frequently or far apart.


Diagnosis of Giardia in Dogs



Your veterinarian will either study a stool sample or take a swap and
wipe it at your dogs rectum. It is possible that the swap will not show
any causes of giardia in dogs, yet your dog still has the disease. Your
doctor will take 3 samples collected at least 2 days apart. There are
also new blood tests that can detect the disease (called ELISA or IFA).


The veterinarian will also need to differentiate giardia from
other illnesses that have similar symptoms such as inflammatory bowel
disease, pancreatic insufficiency, bacterial overgrowth and
immunodeficiency.


If giardia cysts are discovered during a routine examination
of feces, it is up to the veterinarian and dog owner as to whether or
not treatment is needed in dogs that are not showing any symptoms.


Treatment of Giardia in Dogs



The FDA has not approved any drugs for specific use against canine giardia. However, there are drugs commonly used by veterinarians which are highly effective in treating the infection as well as to stop the shedding of cysts in feces. The drugs Fenbendazole and Febantel are safe and effective in treating the disease and in eliminating shedding cysts. The drug metronidazole (trade name Flagyl)  is an alternative, but may have some side effects/toxicity, although positive include that it can be effective against other causes of diarrhea as well.


Albendazole is not routinely used until other medications are tried
since it can have more side effects.


A
complete list of dog giardia medications includes:



  • Metronidazole (Flagyl®,25-30 mg/kg, 7 days)

  • Fenbendazole (broad spectrum dewormer,  Panacur 50 mg/kg once daily, 3 days)


  • Furazolidone (Neftin, 4 mg/kg, 10 days)


  • Tinadazole (44 mg/kg once daily, 7 days)


  • Albendazole (Valbazen, 25 mg/kg, 2 days)




Immunotherapy with the canine giardia vaccine may help
eliminate the shedding of cysts and diarrhea in dogs that already have
the disease.


One approach for treating giardiasis is to use Panacur for up
to 7 days (based on dog weight, check with your
veterinarian/manufacturers directions).  The medication is
taken orally mixed with food. This is followed by a gap of 2 weeks,
then another 7 days of treatment.  Panacur can be purchased on
line from Amazon.
 Important: Only use an anti-parasitic medication such as
Panacur if your dog has tested negative (does not have) heart worm.
 Dogs with heart worm can be harmed by using these types of
medication as it will kill the worms and cause heart failure. To help
protect your dog’s digestive system during treatment, it is a good idea
to use along with a probiotic
supplement
.  


Supportive Treatment for Giardia in Dogs


Adding fiber to your dogs diet can help protect against the
causes of giardia in dogs and to help speed recovery.
 Fiber has the effect of helping to control symptoms such as
bacterial overgrowth and makes it more difficult for the giardia
protozoan to cling to the dogs intestines.  Several natural
remedies can provide added support in
addition to the medications prescribed by your veterinarian.
 These include Parasite
Dr.
to help the body naturally eliminate parasites, Natural
Moves
to restore bowel function and Digestive
Support
to improve nutrient absorption that was disrupted by
the giardia.



Dogs do not acquire immunity to giardia after treatment, so they can
contract the disease again. There is a vaccine to prevent the disease.


Giardia Vaccine in Dogs


The giardia vaccine is considered a non-core vaccine, which
means that it is only used in special circumstances where there is a
higher risk of exposure to the disease.  For example if you
live near a lake or other body of water that provides repeat exposure
to the disease for your dog, then the giardia vaccine would be a good
idea.


The initial dose is provided to puppies at 8 weeks of age.
 A second does is provided at 2 to 4 weeks. Adult boosters are
needed each year.


Can Humans Catch Giardia from Dogs?


The causes of giardia in dogs are a different strain of
parasite than the one that infects humans. Types of giardia are for the
most part animal specific.
 The type found in humans, tend to stay in humans, dog
giardia only infests dogs etc. In rare instances, human giardia has
been found in dogs.  While it is believed that it is possible
for dog giardia to infect humans, there is no evidence that this is
true, although more research is needed. 


Prevention of the Causes of Giardia in Dogs


In addition to vaccination, the only way to prevent giardia in
dogs is to eliminate the causes of giardia in dogs which is standing
water or unhygienic kennels or other areas where dogs congregate.
 When walking your dog, try and
provide clean drinking water instead of relying on standing bodies of
water or natural water sources such as lakes or streams.
 There are no over the counter preventatives available like
there are for parasites such as fleas.



Any place water collects should be removed if possible such as places
where there are puddles or poor drainage. Any concrete surface should
be cleaned, dried and sealed. Gravel areas should be replaced. Bleach
may help clean infected areas (1% bleach, 99% water). Lysol, ammonia,
and bleach can also be effective decontamination agents. Look for
products that contain quaternary ammonium compounds.



Removal of Giardia is difficult. They survive the chlorination of
drinking
water and freezing down to –13C.  Cysts can last in the
environment for several weeks.  They can
last even longer if in the water.


To avoid causes of giardia in dogs such as feces, practice
good hygiene such as bagging and disposing of feces in bags, and
removing
and disposing deposited in outdoor areas such as the backyard.


For more information on the causes of giardia in dogs,
download this free
pamphlet from the Companion Animal Parasite Council on Giardia in dogs and people.


References for Causes of Giardia in Dogs:


Standards of Care – How I treat Giardia Infections

Michael R. Lappin, DVM,
PhD, DACVIM

Professor

Department of Clinical Sciences

Colorado State University



Kuenzi Family Pet Hospital

Rodney S. Kuenzi, D.V.M.


Guarding Against Giardia

Maggie Fisher BVetMed MRCVS


Dog
Owner’s Home Veterinary Handbook

James M. Giffin

Liisa D. Carlson DVM


Giardiasis in Dogs and Cats: Diagnosis, Treatment and Zoonotic
Risk

Susan E. Little, DVM, PhD, Dipl. EVPC

Center for Veterinary Health Sciences

Oklahoma State University, Stillwater, OK


Companion Animal Parasite Council Guidelines (CAPCVET.org)





Have a Giardia in Dogs related Question For Our Editors or A Story to Tell About This Topic?


Do you have a dog giardia related question for our editors or a helpful story to share? Please include related information such as age, sex, breed, medical history, symptoms, diagnosis, diet, changes in behavior, diet and medications.


We will do our best to get back to you quickly (depends on how many questions we receive each day). If you do require an immediate response we suggest using this online dog veterinary service that is available now.


Questions from other Readers and Vet Answers


Click below to see contributions from other visitors to this page…





没有评论:

发表评论