Giardia, the Monster Parasite

by Gail Gillogly - Spring 2004

Giardiasis (GEE-are-DYE-uh-sis) was originally called Cercomonas intestinalis by Lambl in 1859, and renamed Giardia lamblia by Stiles in 1915, in honor of Professor A. Giard of Paris and Dr. F. Lambl of Prague. Yet another alias of this single-celled microscopic parasite is referred to as Giardia duodenalis. Whatever the Zoological Nomenclature of the week, I know it only too well as “The Monster Parasite.”

What is a parasite?

Parasites, in general, are organisms which survive on other living organisms known as hosts. They derive their nourishment and protection, as well as live and reproduce, within the tissues and organs of their host. They may be transmitted from host to host through consumption of contaminated food and water or through contact with the stool (feces) of an infected host.
There are various parasites which range in size from tiny single-celled microscopic organisms (protozoa), to visible multi-cellular worms (helminthes) that may be observed with out a microscope.

What exactly is Giardia?

Giardia is a single-celled protozoan organism. Although once thought of as a third world problem, Giardia is common world wide. It is an opportunistic organism and infects a wide range of hosts including wild and domestic animals, birds and, of course, humans too.
In fact the CDC estimates that approximately 2 million Americans contract Giardiasis every year. However, according to the latest research, the giardia that infests humans is a separate organism from that which infests birds. If your bird has giardia it should not be contagious to humans or other types of companions; however, it is extremely contagious to other birds in the home.

giardia troph

Giardia has two stages, the cyst which is the infective stage and the diagnostic stage and the trophozoites, which, while also a diagnostic stage, does not survive away from the host. The cyst are resistant forms which are responsible for the transmission of giardiasis. They are hardy and can survive for several months in cold water or outside of the host. Infection occurs by the ingestion of cysts in contaminated water, food, or by the fecal-oral route. Living in the small intestine (usually the duodenum) excystation releases trophozoites. Each cyst produces two trophozoites, which multiply by longitudinal binary fission, remaining in the lumen of the proximal small bowel where they can be free or attached to the mucosa by a ventral sucking disk. This retards digestion and assimilation of nutrients for the host. Encystation occurs as the parasites transit toward the colon.

What are the symptoms of Giardia in birds?

In some companion birds Giardia may induce pruritis (itching), causing a bird to scream and pull feathers. There is a common giardia picking pattern, which usually involves the chest, underside of the wings, insides of the thighs, shoulders and sometimes the lower back region. Some birds may show signs of dry flaky skin or act as though they have fleas. They may exhibit what is known as “pica,” appearing as if they are licking non-food items, like toys, perches, etc. The stools may be loose, foul smelling, or oily-looking, or they may be passing whole seeds or undigested foods in their droppings. Additionally giardia may cause mortality of baby birds in the nest. Often the babies will be very thin, have poor feathering and continually cry to be fed. Many won’t make it to fledging.
Some birds may never display visual symptoms, yet may have signs of loose droppings, weakness, anorexia, depression, and weight loss. A solitary companion home may harbor giardia for long periods of time before showing signs of illness. A multiple companion family may all harbor this monster parasite with only a couple showing visible signs of distress. This is another reason Giardia is so hard to treat. Many times companions are treated individually. It is my personal opinion that the whole flock needs to be treated if it is a multiple bird home. At one time, Giardia was thought to be carried only by the smaller birds such as cockatiels, budgies, lovebirds, etc. However, in the past several years has it come to the attention of vets and caregivers that the larger species are susceptible as well. Unfortunately, Giardia thinks of them all as wonderful hosts. Another problem Giardia causes is the compromising of the immune system, leaving it unable to ward off secondary infections such as bacterial or fungal infections.

How is Giardia diagnosed?

Since the trophozoites stage is unstable and may disintegrate before it can be seen, as well as the fact that Giardia is shed sporadically in the feces (both, cyst and trophozoites), it can be difficult to detect and to correctly diagnose. Currently, it is felt a fecal trichrome test is the most reliable for diagnosing Giardia. There is an abundance of evidence that birds that have tested negative under other test methods have then tested positive using the fecal trichrome method. The collection of the first morning feces will provide the best opportunity to detect the parasite; the sample needs to be collected fresh, within minutes. Three samples over a period of 3 days is optimum for catching the organism.

What are the conventional treatments?

A 5-day course of Ronidazole is considered to be safe and effective in treating giardia. In 2001, Flagyl (metronidazole) appeared effective in only about 60% of the cases. Currently, some vets feel the effectiveness of Flagyl (metronidazole) is down to 40%. Known side effects of Flagyl are nausea, disorientation, yeast growth, liver failure depression, regurgitation, and nerve damage. It has even been shown to cause cancer in animals.
Another drug, Panacur, (fenbendazole) may also have adverse side effects in birds including feather deformities and liver problems. Another drug that may be somewhat effective is Humatin (paromomycin). This drug must be administered orally by syringe. Some vets are using the drug dimetridazole. It is imported from Germany and is not yet available in the U.S. to treat giardia.
One of the problems in treating giardia is that it has built up a resistance to many of the conventional drugs. This is clear to see as in the case of Flagyl, which dropped from 60% efficacy in 2001 to 40% in 2003. Symptoms of giardia may subside for a couple of months only to return with a vengeance.

How about Holistic treatment?

Some people have tried conventional treatments and are now turning to the holistic approach for a safer, more natural treatment. Giardia can take 3 months of treatment to eradicate. A holistic vet will want to incorporate a program eliminating the parasites and setting up a supportive nutritive and immune-building diet according to your bird’s individual needs.
In the book, “All You Ever Wanted To Know About Herbs For Pets,” by Mary L. Wulff-Tilford & Gregory L. Tilford, the authors recommend tinctures as the best form of herbal intervention because of their high concentrations of readily available constituents. This is the remedy they recommend:

Combine the following tinctures:
2 parts Oregon grape
2 parts licorice
2 parts cleavers
1 part garlic

This formula can be fed to dogs, cats, birds, horses, and other large herbivores at least one hour before feeding, at a dosage of about ¼ teaspoon (1 milliliter) per 20 pounds of the animal’s body weight, twice daily for up to ten days. If positive results aren’t seen within ten days, it’s time to call your holistic vet. Low-alcohol tinctures are best because of their relative ease of administration, but alcohol tinctures can be used provided they are diluted to half-strength with water, meaning you will have to give the animal twice the liquid volume.

Summary of Giardia

Giardia is extremely hard to get a handle on once it has taken up residency. You have to make a personal decision between treating conventionally or holistically. In either case, it is advised you seek a professional to assist you in this battle with “the monster parasite.” It is imperative to keep the cage area as clean and disinfected as possible. This includes the toys, cage bars, perches, play gyms, dishes, etc. The giardia cysts can live outside of the host for months, possibly years. Re-infection rate is high, which makes giardia hard to combat. Take a look at the diet your bird is eating. Can it be improved? Remember that a good diet is the basis for good health and a healthy bird is capable of fighting off intruders while one with a compromised system cannot!

References

Bird Talk issue Sept. 2001
Herbs For Pets by Mary L. Wulff-Tilford & Gregory L. Tilford
http://www.biosci.ohio-state.edu/~parasite/giardia.html
http://www.cdc.gov/mmwr/preview/mmwrhtml/ss4907a1.htm
http://www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/
factsht_crypto_prevent_water.htm
http://www.fsis.usda.gov/oa/pubs/parasite.htm
http://www.dpd.cdc.gov/dpdx/HTML/Giardiasis.htm
http://vm.cfsan.fda.gov/~mow/intro.html
http://www.priory.com/vet/giardia.htm