How to use BioWorma: a step-by-step dosing and application guide

Knowing how to use BioWorma correctly comes down to sequence. Skip a step or get the dose wrong, and the product won't do the job it's built for. Here's the full process, start to finish.

Step 1: Treat the herd first

BioWorma doesn't touch worms already living inside an animal. Before you start it, treat the herd with a suitable injectable, pour-on, or oral dewormer to clear the existing worm burden. This is the step people skip when they're eager to get started, and it's the one that matters most. BioWorma does its work later, in the manure, not before this point.

This sequence isn't arbitrary. BioWorma's active ingredient, Duddingtonia flagrans, targets the larvae stage of the parasite's life cycle, after they've been shed in manure but before they migrate onto pasture. It has no effect on adult worms already established in the animal's gut. Starting BioWorma without clearing that existing burden first just means you're managing two separate problems at once, one BioWorma can't touch.

Step 2: Move animals to low-worm pasture

Once you've treated the herd, move animals onto pasture that hasn't carried the same species for at least six weeks. This gives BioWorma a cleaner starting point. Not every operation has spare pasture to rotate onto, but doing this speeds up how fast the herd's overall worm burden comes down.

Step 3: Identify which animals need it most

Not every animal in the herd carries equal risk, and knowing this changes how you prioritize feeding if resources or labor are tight. Young animals, roughly 3 months to 18-24 months old, and periparturient females (does, ewes, or cows in their last month of pregnancy through nursing) are the most worm-susceptible group. Their immunity is naturally lower during these windows, which makes them both more vulnerable to infection and a larger source of pasture contamination than their size suggests.

That doesn't mean healthy adults can be skipped. Even animals with low fecal egg counts still deposit a meaningful volume of manure on pasture, and it's easy to underestimate how much that adds up across a herd.

Step 4: Dose by bodyweight and mix thoroughly

Dose BioWorma at 0.1 oz per 100 lbs of bodyweight per day, based on the heaviest animal in the group, up to 1,200 lbs. Add another 0.1 oz per additional 100 lbs past that point.

Mix it thoroughly into feed, supplements, premixes, or concentrates. Uneven mixing shortchanges some animals and overdoses others, so take the time to distribute it properly.

If you're using Livamol with BioWorma instead, use a different rate: 1.6 oz per 100 lbs per day. Livamol is a diluted premix (20,000 CFU/gram) compared to BioWorma's concentrated form (500,000 CFU/gram), so it takes more product to deliver the same daily spore count.

Step 5: Feed daily, and track your progress

Feed it daily, not as a one-time treatment. Keep it going through the stretch of the year when temperatures stay above 40°F, since that's when conditions favor larval development on pasture. In most of the country, that covers the bulk of the grazing season.

Check the herd's actual worm burden periodically with a fecal egg count. BioWorma works on the pasture side of the problem, not inside the animal, so a fecal count confirms whether the whole program, dewormer plus BioWorma, is bringing numbers down over time. If one animal's count stays high, flag it to your vet rather than raising that animal's BioWorma dose, since dose scales with bodyweight, not with how bad an individual case looks.

A note on integrated parasite management

BioWorma is designed to work alongside a broader parasite management plan, not replace one. BioWorma's own guidance on getting started points to the principle of refugia, deliberately leaving some portion of the parasite population untreated so it doesn't develop resistance as quickly to the chemical dewormers you're still relying on. A vet, animal health advisor, or your local agricultural extension office can help build a strategy suited to your region's specific worm pressure and climate, since that varies a lot by geography and season.

Where to Buy

Exotic Animal Supply is one of only two authorized US sellers of BioWorma. Orders placed before 2 PM EST ship same-day out of four climate-controlled warehouses across Texas, Florida, and North Carolina. For a full comparison of BioWorma and Livamol with BioWorma, see our product comparison guide.

Frequently Asked Questions

How long does it take for BioWorma to start working?

It starts working within the first day of reaching the manure, but you'll see the real payoff, lower pasture contamination, build gradually over the following weeks, not overnight.

How should I store BioWorma?

Keep it in a cool, dry place out of direct sunlight, in its original container.

Can I stop feeding BioWorma once the worm count looks good?

No, it's built for ongoing use, not a short course. Stopping once counts improve usually lets pasture contamination climb back up the following season.

What if a fecal egg count comes back high on one animal?

Talk to your vet rather than increasing that animal's BioWorma dose. Dose scales with bodyweight, so an individual high count usually points to something else going on, not an underdose.

Which animals should get priority if I can't treat the whole herd at once?

Young animals under about 18-24 months and pregnant or nursing females, since both groups have lower natural immunity and contribute disproportionately to pasture contamination.