How To Kill Giardia In Grass

For homes with pets or occasional neighborhood animals, giardia is a potential problem.

This parasite can survive in a lawn for several weeks, and if your dog, cat, or another mammal is infected and visits your yard, it can live in the moist soil and potentially spread and infect, or reinfect, your pet or you yourself. 

Giardia is one of the most common parasites, and it’s impossible to control in public outdoor spaces. Luckily, there are ways to remove it from the yard if it shows up and reduce the chances of it being able to appear in the first place.

What Is Giardia?

Giardia is a waterborne, single-celled parasite that can infect mammals, including people. It’s usually contracted by drinking from standing water sources that has been contaminated with the organism (like fountains, ponds, lakes, and other water systems). Once consumed, giardia lives in the intestine of hosts and is spread by fecal matter.

It’s one of the most commonly spread parasites, and it may show up in a lawn from outdoor pets and other neighborhood animals, particularly dogs that visit dog parks or kennels. Many animals don’t show signs of infection, but disease can develop from a severe case. 

How Does A Lawn Get Infected With Giardia?

When wild animals, stray cats, dogs, or your own or someone else’s pet is infected, giardia can be left on a lawn when the animal defecated, and some of the parasites are expelled. The microorganisms develop a hard, fluid-filled casing to survive the dry conditions outside of a host, going dormant and waiting in the soil until they’re revived in water or consumed by a new host.

Giardia can survive in the soil for several weeks, and it’s especially transferrable by wet lawns. A yard that doesn’t drain well is at risk of pooling water and providing the conditions for giardia to survive longer and multiply in-place. 

What Kills Giardia Naturally?

Since the giardia parasite survives in water and moist conditions like soil and food, a hot and dry environment is one-way nature can take care of giardia. A lawn that is well-aerated, drains well, and gets direct sunlight is less likely to host giardia than one that retains too much water or maintains damp conditions. 

How Do You Clean Giardia From Soil?

If your pet is showing signs of giardia (more on that later), getting a vet to verify an infection is the first step in knowing whether your lawn may be infected or not with the parasite. On the other hand, an unknown animal may have visited your lawn. In either case, removing fecal matter is the first step to preventing the parasites from settling into the ground and spreading. The sooner, the better.

Very hot water will kill giardia in contaminated soil without using any other substances. Boiling water and pouring it over an area after removing fecal matter can prevent potential giardia from surviving and taking hold. 

A diluted bleach solution is one of the most popular ways to get rid of the parasite without harming your lawn. A diluted bleach and water mixture of 3/4 cup of bleach per gallon of water can be applied with a pump or backpack sprayer for full-yard coverage. 

Apply the diluted bleach solution in the morning, after any dew has dried, but before the midday heat so the bleach doesn’t evaporate quickly. After sitting for 30 minutes, it should be rinsed off. This can be done by running a sprinkler for 10 minutes every two hours for the rest of the day (of course, if your yard isn’t well-draining, a more diluted solution will need less rinsing). Keep your pet out of the yard for a few weeks or a month while the parasite is worked out of the soil.

If you’re spot-treating an area for giardia, another strategy is to clean the area, then place a tarp over it to keep the area extra warm. Using a hose to water under the tarp once a week for 6 weeks, the moist ground will hold more heat, and the tarp will keep that heat in, to kill off the giardia organisms in the soil. 

How Do I Prevent Giardia From Infecting My Pet And My Lawn?

Giardia in Drinking Water

To prevent giardia from taking hold in your lawn, there are some ordinary lawn care practices that will keep the ground from being hospitable to the organisms:

  • Clean up after your pets right away – When you take your dog(s) out, you should clean up after them right away, even in your own yard. For cats, changing their litter regularly is important, especially for outdoor cats that may contract giardia outside.
  • Don’t allow your pets to drink from ponds, streams, or puddles – Giardia spreads best by water, especially still water that is exposed to lots of animals outside. Drinking untreated water is the main way animals and people contract giardia.
  • Aerate the lawn – Aeration is one of the best ways to help open up your lawn and mix air into the topsoil. Soil that drains and dries out won’t be able to host giardia as long as wet soil. Compacted soil that pools water, on the other hand, can create a comfortable environment for the parasite.
  • Amend the soil with sand to increase drainage (as appropriate) – While some types of grass like moist soil, no kind of grass likes soil that holds too much water. Clay-heavy soils should be aerated and amended with sand and/or gavel to help the ground drain better.
  • Level the lawn – An uneven lawn may lead to water pooling in certain areas, which can lead to soil compaction and even less drainage. Aerating, amending, and leveling the soil all contribute to a well-drained lawn.
  • Have your vet check for giardia during annual checkups – Many animals that have a giardia infection don’t show symptoms, and only severe cases may show signs of the infection. Puppies and kittens, however, are more likely to show symptoms, as well as animals who have another illness and a weakened immune system. Signs include vomiting, diarrhea, decreased appetite, and itching. If they contract giardia, there are medical treatments available, including medications and probiotics, or a change in diet may be recommended to strengthen their immune system.