GIARDIA IN DOGS
What is Giardia?
Giardia is a microscopic, protozoan parasite that causes inflammation of the intestinal tract and subsequent diarrhea that can be very serious. It has been referred to as backpackers’ disease because of the risk of exposure when hiking.
How common is Giardia?
Giardia is common in pets. The Companion Animal Parasite Council reports that while “regional differences in Giardia prevalence exist, infections in dogs averaged 15.6%.”
How does it spread?
Giardia is transmitted by oral ingestion of water or food that has been contaminated by feces of infected animals.
What are the signs of Giardia?
The clinical signs of Giardia in animals may include:
Greasy stools that tend to float
Stomach or abdominal cramps
Upset stomach or nausea/vomiting
Dehydration (loss of fluids) and weight loss
How is Giardia diagnosed?
Smear — Sometimes the immature trophozoites can be seen in a smear of the feces under a microscope. Because they are only passed intermittently, even in symptomatic dogs, multiple smears over time must be done; still, they may fail to reveal the parasites.
Fecal flotation — Fecal floatation for cysts is more diagnostic, but the trophozoite stage won’t be seen by floatation—the floatation solution destroys the trophozoites.
ELISA and IFA assays — Assays for Giardia antigens in feces are the most diagnostic test we have available. They are very sensitive, easy to run and very specific tests.
All dogs with clinical signs of Giardia should be tested.
How is Giardia treated?
Effective treatment involves metronidazole in combination with a drug called fenbendazole. Also recommends that bathing accompany treatment.
Can I get Giardia from my dog?
Transmission from dogs to humans appears to be rare. While there have been cases of human infection that could be traced back to dogs, human infections are primarily acquired from other humans. Most human infections occur from environmental food or water contamination by infected humans.
How do I prevent Giardia?
Treatment and prevention go hand in hand since re-infection is possible. Medications, sanitation and environmental control are important. Unfortunately, sanitizing water and soil is very difficult. It is also important that all pets showing clinical signs be treated to prevent re-infection.
Infection occurs commonly from drinking water in ponds, lakes, streams and rivers. Even mountain spring water sources may be contaminated. Avoid drinking water from these sources and do not allow your pet to drink from them either. When you go hiking, always carry fresh water — sufficient for yourself and your dog. If you must drink from wilderness sources, the water should be purified using filters, chemical purifiers or by boiling it before drinking. If you take your dog to a public park or a dog park and allow your dog to drink from a public "dog dish" - imagine how often that dish is washed and how many dogs drink from it on a given day! We try to carry a water dish from home or use a single-use bowl if we have to provide water to our pets outside of home. Giardia can live for months in standing water and mud. Prolonged freezing temperatures will kill most or all Giardia but as soon as temperatures warm up in spring, Giardia survival rates increase. You can understand how warmer weather, muddy dog runs and dog parks create perfect breeding grounds for Giardia. There is simply no way around it. It will always be present in city dog parks, dog runs and in kennels. Dogs can ingest the Giardia cyst by drinking infected water, eating mud or feces or just stepping in it then licking their paw.
Once the Giardia enters the dogs body, several things can happen:
1. The dog's immune system will eliminate the protozoan from the body on its own. Puppies in general will not have an immune system strong enough to do this but are more likely to develop active Giardia.
2. The protozoa enters the dog's small intestine and starts to reproduce Giardia cysts that can then infect other dogs/cats/humans.
3. The dog might or might not show symptoms of infection. The dog can become a silent carrier, infecting other dogs, not showing any symptoms OR the dog can become ill, be taken to the veterinarian, diagnosed and treated for Giardia. Note that having once been infected with Giardia does not guard against future infections.
A dog suffering from active Giardia might have diarrhea (smelly and mucusy stool) vomiting, dull coat and weight loss. Many dogs though, will test positive for Giardia but never show any of the above symptoms. Also, some dogs can be infected and not show symptoms for years but a sudden stress on the immune system can bring out the active disease. In general, the incubation period for Giardia is 7 days to 3 weeks (showing symptoms or not.)
If your dog has been diagnosed with Giardia, follow your veterinarian's instructions. Giardia is commonly treated with Panacure or Metronidazole. Wash dog bed covers and use Clorox/bleach based products on surfaces to kill the microscopic protozoa. Of course wash your hands after handling dog feces!
The good thing is that, in general, Giardia is easy to treat (although some dogs can get stubborn cases), especially if the dog is healthy with a strong immune system and well cared for. Typically, Giardia is NOT not detrimental to the dog's health. It can however become annoying and expensive to keep treating your dog for Giardia AND some dogs seem to be more susceptible than others.
So what does Giardia mean to us and how do we handle it ?
We regularly de-worm our dogs and follow strict puppy de-worming protocol. We do a complete stool sample on every dog at least annually, treat accordingly if there are any positive results and re-test after a treatment. We sanitize daily and keep our puppies and dogs clean. Still, we get Giardia positive once in a while. Kennels are especially at risk for internal parasites, for many reasons. One of the reasons - small puppies, that are especially open for worms due to their not yet formed immune system. Pregnant and nursing bitches are also subject to worms, with their immune system being compromised for pregnancy and after delivery. We have many dogs visiting, too. We will never be able to hinder dogs with Giardia to attend our kennel. We will not ask every family to do a Giardia test before coming to visit or for a training. It is not practical for any dog owner to bring their dog to the veterinarian for a fecal test every time they are about to visit us or to board their dog at our or another boarding facility. Further, there will always be false negative tests as the swimming protozoa itself and the cyst containing the "egg" is not always present in every fecal sample depending on the protozoa life cycle.
Here at VHG, we disinfect all indoor surfaces and wash all dog bed covers regularly and change puppy mats on a daily basis and we pick up poop all day long. We can not however, eradicate every puddle of water on our Beloved Acres Farm or disinfect nature, which will invariably contain Giardia at times. Even our chickens that are free-ranged can get Giardia! Due to severe winters here in the Midwest, Giardia is not a problem year around at our kennel. It is a different story in where freezing temperatures can stay away for weeks even during the winter months. However, as the temperatures continue to warm up it will become activate at our kennel just as in the other ones everywhere in the country and we will see cases increase.
What we do appreciate is when our families tell us if their dog has been diagnosed with Giardia so we can keep track of how common it is throughout the season. We also highly encourage every dog owner to test their pet for Giardia and treat it accordingly. Communications and sharing of information is always best way to keep parasites at bay!