Giardia: A Parasite of Many Species

If you have a friend who camps or fishes, you may have heard that they had been infected with Giardia. Or your veterinarian may have told you that your cat or dog had Giardia. In either case, you probably wondered, can I catch it as well?

Giardia is a protozoan parasite (one-celled organism) that can infect a variety of species, including pets and people. The human form of Giardia really likes people, the canine form likes dogs, the feline form likes cats, and the ruminant form likes cows and sheep. But it is possible for any of the forms to infect any of the other species.

In an animal or a person, Giardia lives in the intestinal tract. It may cause no symptoms, especially at first, but with time and as the organism becomes more numerous as it propagates, diarrhea commonly occurs. Some people may have more long standing or severe disease; then the symptoms can also include abdominal cramping, nausea, vomiting, loss of appetite, and weight loss. Pets also get diarrhea when infected, but they tend to get diagnosed faster as it is common to do regular fecal testing in veterinary medicine.

Giardia cysts are passed in the feces of infected animals and people. These cysts are resistant to environmental extremes, and thus can live in feces or fecal contaminated soil, surfaces, and especially water, for a long time.

Pets and people are usually exposed from contaminated sources in the environment. Giardia is a common cause of recreational water illness, from pools, water parks, water play areas, hot tubs, lakes, rivers, ponds, streams, and oceans. Pets and people swallowing even a small amount of water can become infected. You share the water, and the germs in it, with every person or animal who enters that water. The infective Giardia cysts can also be present on other surfaces contaminated with feces such as bathroom fixtures, changing tables, diaper pails, and toys. Uncooked, fresh produce can be contaminated as well.

Luckily, Giardia is easily diagnosed in veterinary medicine. There are two tests commonly performed: a microscope test call an "ova and parasite" (O&P) where the technician looks for the presence of the parasite in a solution made from the feces and then centrifuged. The other test also uses a stool sample, but uses a more sophisticated method to check for any DNA of the Giardia parasite.

Treatment is usually very rewarding. Drugs commonly used are metronidazole or fenbendazole, although in stubborn cases they may be used at the same time.

What can you do to prevent infection in the first place? Have your pets' stool checked regularly for parasites (at least twice yearly). Practice strict hygiene, cleaning surfaces that could become contaminated by stool. Wash your hands after going to the bathroom, and insist your children do as well. Every day, place any dog and cat feces from your property into plastic bags that will go to a landfill. If you have a pool, keep it well maintained, don't allow any person or pet in the pool if they have diarrhea, and have everyone shower (with soap) before entering the pool. Don't allow children to defecate while in the pool. Don't swallow any water when you are in a pool or any other type of recreational water. Wash all produce well before consuming.

Giardia is a common parasite. Your veterinarian can check your pets for Giardia by performing a stool test, and treat if necessary. You can prevent your family from being infected by some common sense, good hygiene practices.

Sources:

Companion Animal Parasite Council
Centers for Disease Control and Prevention

Location

Find us on the map

Office Hours

Our Regular Schedule

Monday:

7:00 am

6:00 pm

Tuesday:

7:00 am

6:00 pm

Wednesday:

7:00 am - 12:00 pm

2:00 pm - 6:00 pm

Thursday:

7:00

6:00

Friday:

7:00 am

6:00 pm

Saturday:

8:00 am

2:00 pm

Sunday:

Closed

Closed

Testimonials

Read What Our Clients Say

  • "Thanks for the great peace of mind when I bring Oreo in . . . I know he is always getting the most technically advanced treatment that veterinary medicine has to offer! Thanks so much . . . I trust my best friend in your hands! Thanks so much for all that you have done for us!

    You guys are the best pet clinic in the area--really!"
    Steve & "Oreo"
  • "Dr. Gonzales, thanks for making my life easy when it comes to bringing Hershey in to the see you! Although, I think he may have a crush! I am convinced it's a crush . . . or those treats are doggone divine! But how could any four-legged creature resist? In all seriousness, thanks for providing Hershey and me the finest. most complete pet care available . . . with a lot of love. I have seen a lot of vets in the past and your genuine love and care is truly rare."
    Jennifer & "Hershey"
  • "Thanks to the Drs and professional staff at Pets First Veterinary Center. I feel like you all truly love what you do! Every time I come in to see you, both me and my kitten have had such a pleasant experience. Everyone is so friendly and knowledgeable--I'm really impressed! Ever since I moved to San Antonio you have made me feel so welcome to the area and to your family."
    Jack & "Jill"
  • "Thanks Dr. Gonzales for your loving and professional care for our newest family member! We appreciate you and your staffs' genuine concern for all our pets for the past 10 years. We have always felt like we have been treated as part of the Pets First Veterinary Center family. Its so reassuring to know that we don't have to worry when we leave our dog for medical treatment or a boarding stay. Thank you so much!"
    The Johnson Family & "Magic"
  • "I think the world of Dr. Wright. Not only does she and team at Pets First Veterinary Center provide the best veterinary care possible, but also unmatched personal service and of course lots of love! I trust you with my most precious posessions...and refer all my friends and family to Pets First Veterinary Center.

    Thanks so much to all of you!"
    Maya, "Amor & Abrazo"