Cattle in a field
Cattle in a field

Deworming Legends

Cattle dewormers for proven parasite control

There are a lot of cattle dewormers out there. These six have proven themselves in the pasture and herds for decades. Here, there's no room for anything less than legendary.

The Four Pillars of sustainable deworming

Legendary dewormers demand a legendary approach. At Boehringer Ingelheim, these Four Pillars guide a smarter, more sustainable parasite-control strategy for cattle.

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Diagnostics 

Monitor deworming efficacy with ongoing surveillance and routine diagnostic testing.

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Combination Treatment

Use two or more dewormers from different drug classes with different modes of action to reduce the amount of parasite survivors.

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Refugia

A portion of the parasite population not exposed to selection pressure. Parasites are left in “refuge” from the dewormer. Consult with your veterinarian.

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Management

Forage height, pasture management, stocking density, overgrazing and rotation impact deworming programs.

Supporting sustainable parasite control in cattle

Hardworking dewormers are only part of the equation. 
Long-term parasite control depends on how they’re put to work. And don’t just take our word for it. Hear from experienced producers and veterinarians as they discuss what sustainable parasite control really takes in Out Here with the Legends.

LongRange eprinomectin bottles in different sizes for cattle parasite control, with green packaging.

LONGRANGE® (eprinomectin)

The first and only long-acting dewormer delivering up to 150 days of parasite control in a single dose.1 Extended protection helps support season-long performance.

LONGRANGE® (eprinomectin)

The first and only long-acting dewormer delivering up to 150 days of parasite control in a single dose.1 Extended protection helps support season-long performance.

LongRange eprinomectin bottles in different sizes for cattle parasite control, with green packaging.
All of the sizes of Eprinex in a line

EPRINEX® (eprinomectin)

This pour-on cattle dewormer kills 39 key species and stages of internal and external parasites with up to 99.9% efficacy,2 and has been proven to add 36 pounds per head over 105 days vs. untreated controls.3

EPRINEX® (eprinomectin)

This pour-on cattle dewormer kills 39 key species and stages of internal and external parasites with up to 99.9% efficacy,2 and has been proven to add 36 pounds per head over 105 days vs. untreated controls.3

All of the sizes of Eprinex in a line
All of the Synanthic products in a row

SYNANTHIC® (oxfendazole oral suspension)

A fast-acting, low-dose, white dewormer that reaches peak potency within 20 hours.4* Effective for the control of multiple stages of internal parasites, including stomach worms, intestinal worms, lungworms and tapeworms.

SYNANTHIC® (oxfendazole oral suspension)

A fast-acting, low-dose, white dewormer that reaches peak potency within 20 hours.4* Effective for the control of multiple stages of internal parasites, including stomach worms, intestinal worms, lungworms and tapeworms.

All of the Synanthic products in a row
Ivomec Plus Product Family

IVOMEC® PLUS (ivermectin and clorsulon)

Combines ivermectin and clorsulon to deliver broad-spectrum control against 30 species and stages of internal and external parasites, including adult liver flukes.5

IVOMEC® PLUS (ivermectin and clorsulon)

Combines ivermectin and clorsulon to deliver broad-spectrum control against 30 species and stages of internal and external parasites, including adult liver flukes.5

Ivomec Plus Product Family
Three Ivomec boxes: 1000 mL, 500 mL and 50 mL

IVOMEC® 1% (ivermectin)

The first cattle parasiticide approved by the FDA to control more than 30 species and stages of internal and external parasites in a single dose.6,7

IVOMEC® 1% (ivermectin)

The first cattle parasiticide approved by the FDA to control more than 30 species and stages of internal and external parasites in a single dose.6,7

Three Ivomec boxes: 1000 mL, 500 mL and 50 mL
Product shot of all the Ivomec Pour On Sizes

IVOMEC® Pour-On (ivermectin topical solution)

Controls over 30 species of internal and external parasites.8 With excellent control of mange and lice, it’s the trusted choice for a topical ivermectin solution.

IVOMEC® Pour-On (ivermectin topical solution)

Controls over 30 species of internal and external parasites.8 With excellent control of mange and lice, it’s the trusted choice for a topical ivermectin solution.

Product shot of all the Ivomec Pour On Sizes

LONGRANGE IMPORTANT SAFETY INFORMATION: Do not treat within 48 days of slaughter. Not for use in female dairy cattle 20 months of age or older, including dry dairy cows, or in veal calves. Post-injection site damage (e.g., granulomas, necrosis) can occur. These reactions have disappeared without treatment. Not for use in breeding bulls, or in calves less than 3 months of age. Not for use in cattle managed in feedlots or under intensive rotational grazing. Pregnant women should wear gloves and exercise caution or avoid handling this product.

 

EPRINEX IMPORTANT SAFETY INFORMATION: No meat or milk withdrawal is required when used according to label. Do not use in calves intended for veal or unapproved animal species, as severe adverse reactions, including fatalities in dogs, may result.

 

SYNANTHIC RESIDUE WARNINGS: Cattle must not be slaughtered until seven days after treatment. Because a withdrawal time in milk has not been established, do not use in female dairy cattle of breeding age.

 

IVOMEC PLUS IMPORTANT SAFETY INFORMATION: Do not treat cattle within 21 days of slaughter. Do not use in female dairy cattle of breeding age or in veal calves. Do not use in other animal species not on the label, as severe adverse reactions, including fatalities in dogs, may result.

 

IVOMEC 1% IMPORTANT SAFETY INFORMATION: Do not treat cattle within 35 days of slaughter. Do not use in female dairy cattle of breeding age or in veal calves. Do not treat swine within 18 days of slaughter. Do not use in other animal species not on the label, as severe adverse reactions, including fatalities in dogs, may result.

 

IVOMEC POUR-ON IMPORTANT SAFETY INFORMATION: Do not treat cattle within 48 days of slaughter. Do not use in female dairy cattle of breeding age or in veal calves. Do not use in other animal species not on the label, as severe adverse reactions, including fatalities in dogs, may result.

 

References

1 Dependent upon parasite species, as referenced in FOI summary and LONGRANGE product label.

2 Based on EPRINEX label claims and FOI summary.

3 Beckett JL. Efficacy of pour-on dewormers differing in active ingredient and carrier on weight gain and fecal egg count in stocker beef cattle. Agricultural Research Institute, Cal Poly State University. 2001.

4 Prichard RK, Hennessy DR, Steel JW, Lacey E. Metabolite concentrations in plasma following treatment of cattle with five anthelmintics. Res Vet Sci. 1985;39(2) 173–178.

5 Based on IVOMEC Plus label claims and FOI summary.

6 Gadberry S, Pennington J, Powell J. Internal parasites in beef and dairy cattle. University of Arkansas Division of Agriculture, Cooperative Extension Service. 2019. https://dairy-cattle.extension.org/internal-parasites-in-beef-and-dairy-cattle/. Accessed Oct. 31, 2023.

7 Based on IVOMEC 1% label claims.

8 Based on IVOMEC Pour-On label claims.

*Clinical relevance has not been determined.

 

EPRINEX®, IVOMEC®, LONGRANGE®, SYNANTHIC® and the Cattle Head Logo® are registered trademarks of Boehringer Ingelheim Animal Health USA Inc. ©2026 Boehringer Ingelheim Animal Health USA Inc., Duluth, GA. All rights reserved. 
US-RUM-0079-2025-V2