Giardiasis is a common parasitic infection that causes diarrhea in dogs, and also can affect most domestic and wild mammals, birds, and people. With the potential of infection for both you and your dog, studying up on this insidious parasitic disease can help keep you healthy and safe, and our Star of Texas Veterinary Hospital team has the information you need.
What is Giardia in dogs?
Giardia is an intestinal protozoan parasite found in soil, water, and food that has been contaminated with infective feces. While many Giardia species can infect people and animals, the one pet owners need to be most aware of is Giardia duodenalis.
As a protozoan parasite, Giardia does not produce eggs; instead, it has two forms. Trophozoites are the flagellate, vegetative stage that live in the intestines of infected dogs, and cysts are trophozoites protected by an outer cell that are shed in the dog’s stool.
When cysts are passed in the stool, they are immediately infectious. Infected dogs can shed cysts continually over several days or weeks, but the shedding is often intermittent, especially if a dog has chronic Giardiasis. However, even though the infective cysts may be shed intermittently, they can survive for months in a cool, damp environment.
How can my dog contract Giardia?
Dogs can contract Giardia by ingesting water, soil, food, or objects contaminated with infective feces. Ingesting just a few Giardia cysts can lead to infection, and the cysts’ hardiness makes environmental management critical in breaking the infection cycle.
Common examples of how dogs contract Giardia include:
- Drinking from a contaminated puddle
- Licking their paws after walking through infective feces or digging in contaminated dirt
- Eating contaminated grass
Dogs also can reinfect themselves with Giardia by grooming their hind end, or walking in a contaminated yard.
What signs are seen with Giardia infections in dogs?
Many dogs infected with Giardia will show no signs, but young dogs or those with weakened immune systems are more likely to display illness.
The most common Giardiasis signs in dogs include:
- Acute diarrhea
- Soft, poorly formed, pale stool
- Malodorous stool
- Mucus in the stool
- Fatty appearance to the stool
- Abdominal discomfort
Severe cases can cause lethargy, lack of appetite, and weight loss.
How is Giardia diagnosed in dogs?
To diagnose your dog with Giardia, our Star of Texas Veterinary Hospital team will perform a fecal exam. However, diagnosis can be tricky because of intermittent cyst shedding. A series of stool samples may be needed to find Giardia cysts, but Giardia trophozoites also can be identified with a fecal exam if the cysts are not currently being shed.
If the history of your dog’s clinical signs and their stool appears indicative of a Giardia infection, but no cysts or trophozoites are seen on a fecal exam, antigen testing is available. This test detects Giardia-specific antigens, which are proteins produced by the parasite.
How is Giardia treated in dogs?
The goal of Giardiasis treatment is to stop the diarrhea and resolve other clinical signs. If your dog has Giardia, but appears healthy with normal stool, treatment may not be necessary.
Common Giardiasis treatments for dogs include:
- Medication — While there is no approved treatment for canine Giardiasis in the United States, deworming medications and antibiotics can help eradicate the parasite and clear up diarrhea.
- Cleaning — Giardia cysts are susceptible to most common household disinfectants and steam-cleaning, so disinfect all surfaces where your dog lies to prevent reinfection. After disinfecting your home and picking up your dog’s stool outside, wash your hands thoroughly with soap and water.
- Bathing — Bathing your dog regularly to remove fecal material during Giardiasis treatment can help prevent reinfection, as can a thorough bath on the last day of treatment. Trimming your dog’s fur around their hind end can help keep them clean and prevent cysts from clinging to the fur.
- Diet — A prescription diet that is easy to digest and reintroduces healthy gut flora can help resolve diarrhea.
Can I get Giardia from my dog?
People and many other animal species also can develop Giardia infections, although the parasite strains that affect each species often differ. For this reason, it is rare for people to contract Giardiasis from their dogs, but good hygiene is always important to minimize disease and parasite transmission.
Unresolved diarrhea can not only make your dog miserable, but it also can take a serious toll on their physical health. If your four-legged friend has diarrhea that does not clear up within a couple days, schedule an appointment with our Star of Texas Veterinary Hospital team.
