Panacur, known generically as fenbendazole, is a broad-spectrum dewormer used to treat a range of internal parasites in animals, including dogs, cats, horses, and livestock. It's effective against roundworms, hookworms, whipworms, and certain tapeworms. It also works on some protozoa, like Giardia. While it’s widely used and trusted, pet owners often want to know how fast it starts working after administration. The answer depends on a few key factors: the type of parasite, the animal being treated, the severity of the infestation, and the specific treatment regimen used.

How Fast Does Panacur Work in Dogs?

In dogs, Panacur starts working within hours of ingestion. Once swallowed, the medication is absorbed into the gastrointestinal tract, where it begins to target the parasites. While you might not see immediate outward results, the worms begin dying off soon after the medication reaches the gut. Typically, noticeable improvement—such as fewer worms in the stool or reduced gastrointestinal symptoms—can be seen within 24 to 48 hours. Buy Panacur Tablets For Dogs Online at top pharmacy Medzsupplier.

For Giardia infections, which require a bit more persistence, treatment usually lasts 3 to 5 days, and full effectiveness might not be evident until the entire course is finished. Even then, follow-up tests may be needed, as Giardia can be tough to eliminate completely with one round.

How Fast Does Panacur Work in Cats?

Panacur is less commonly used in cats but can still be effective. When prescribed, it’s often for roundworms or hookworms. As with dogs, Panacur starts working in cats within a few hours of ingestion. However, symptom relief or visible results might take a day or two, depending on the parasite load and the cat’s overall health.

It’s worth noting that cats are often more sensitive to medications, so vets may use Panacur off-label with precise dosing. Always follow the vet’s instructions closely.

How Quickly Does Panacur Work in Horses and Livestock?

In horses and livestock, Panacur is commonly administered as a paste, liquid, or granules. It starts killing parasites shortly after ingestion, and most of the deworming effect occurs within the first 24 hours. However, depending on the type of worm burden—particularly in the case of encysted small strongyles in horses—a longer or repeated treatment may be necessary.

For instance, a five-day "power pack" treatment is sometimes prescribed in horses to fully address these tougher cases. In cattle, goats, and sheep, response time is similar: the drug is fast-acting, but full effectiveness depends on the parasite load and whether a follow-up treatment is needed.

How Long Does Panacur Stay in the System?

Panacur doesn’t linger in the body for long. Its half-life is short, and most of the drug is excreted within a couple of days. That’s why it’s typically given as a multi-day course—usually 3 to 5 days—to maintain enough presence in the body to kill parasites throughout their life cycle.

After starting Panacur, you might notice dead worms in your pet’s stool. This can happen within a day or two. Some animals may have mild gastrointestinal upset as the worms die off, especially if the infestation was heavy.

In some cases, symptoms like diarrhea, vomiting, or lethargy may seem worse before they get better—this can be part of the die-off reaction. It’s typically short-lived, but if it continues for more than a couple of days, it’s a good idea to consult your vet.

Final Thoughts

Panacur begins working within hours and typically shows noticeable effects within 24 to 48 hours. However, full effectiveness depends on completing the prescribed course. It's important to follow your vet’s instructions exactly, especially with stubborn infections like Giardia or encysted parasites in horses. If you’re unsure whether the medication is working, or symptoms persist beyond a few days, don’t wait—check in with your vet to determine if additional treatment is needed.