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Dewormers & parasiticides · Over the counter

Synanthic withdrawal time for cattle

oxfendazole. Used for stomach and intestinal worms and lungworms — concentrated oral drench.

Slaughter withdrawal

7 days

Route / formulationSlaughter withdrawalDetail
Oral drench (22.5% or 9.06% suspension)7 days

Milk & dairy: Do not use in female dairy cattle of breeding age (no milk withdrawal established).

Synanthic is the third benzimidazole drench, with the shortest hold of the class: 7 days. The concentrated 22.5% suspension keeps dose volumes small, which crews appreciate at the chute.

Like Valbazen, it lacks a dairy approval — the dairy-legal member of the family is fenbendazole (Safe-Guard).

What the label requires

  • Slaughter withdrawal: 7 days.
  • Shortest withdrawal of the white-wormer drenches.
  • Not for dairy females of breeding age.

Always follow the label on your bottle and your veterinarian's directions. Extra-label use — any different dose, route, or frequency — voids the withdrawal above; your vet sets the interval instead, usually via FARAD. When in doubt, hold longer. Label data checked July 18, 2026. Source: FDA label (DailyMed).

Never ship a treated animal by mistake

Log a treatment in HerdCommand with its withdrawal days and the animal carries a hold flag until the date clears — and the sale workflow warns you before a flagged animal ends up on a load. Works from the phone in your pocket, at the chute.

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Common questions

How long is the Synanthic withdrawal?

7 days from treatment to slaughter — the shortest of the benzimidazole drenches (Safe-Guard suspension is 8, Valbazen is 27).

Other withdrawal times