Ultimum Long-Acting Horse Wormer & Boticide Gel by Virbac

Ultimum by Virbac — a long-acting horse wormer and boticide gel that delivers extended-duration parasite control with moxidectin + praziquantel. The most comprehensive single-dose wormer in the Virbac equine range, covering encysted small strongyles, all major adult worms, tapeworm and bots. Ships USA, Canada and worldwide — no vet prescription required.

The long-acting wormer that catches what others miss

Ultimum is the heavy artillery of the Virbac equine wormer range. It combines moxidectin — a long-acting macrocyclic lactone that catches encysted small-strongyle larvae most other wormers miss — with praziquantel for full tapeworm cover. The result is up to 13 weeks of strongyle protection from a single dose, plus the most complete worm-stage coverage available in any single equine product.

Encysted small strongyles are the parasite stage that causes the most damage in adult horses — they hide in the wall of the large intestine where ivermectin and benzimidazole wormers can't reach them. Moxidectin (the active in Ultimum) is one of the only wormers that kills them. If your horse has had heavy strongyle burdens, lives on a high-traffic property or has just been added to a new herd, Ultimum is the wormer to reach for.

What Ultimum kills

• Encysted small strongyles (cyathostomin L3 and L4 larvae) — the key difference vs ivermectin-based wormers
• Adult small strongyles
• Large strongyles (all three species, including migrating larvae)
• Roundworms (Parascaris equorum)
• Pinworms (Oxyuris equi)
• Threadworms (Strongyloides westeri)
• Stomach worms (Habronema, Trichostrongylus axei)
• Lungworms (Dictyocaulus arnfieldi)
• Bots (Gastrophilus species — all three)
• Tapeworms (Anoplocephala perfoliata, A. magna, Paranoplocephala mamillana) — all three species

Active ingredients

Ultimum contains moxidectin and praziquantel in a gel paste formulation. One syringe doses a horse up to 700 kg (1,540 lbs).

How to give Ultimum

• Estimate your horse's weight with a weight tape or scale
• Set the dose ring to the appropriate weight mark
• Insert the syringe at the back of the tongue and depress fully
• Raise the head briefly to ensure the paste is swallowed

Why pick Ultimum?

• Kills encysted small-strongyle larvae — the parasite stage that ivermectin-based wormers miss
• Up to 13 weeks of strongyle suppression from a single dose — much longer than ivermectin
• Full tapeworm cover with praziquantel
• Bot cover for the autumn worming
• The single most comprehensive equine wormer in the Virbac range

When to use Ultimum

• Once or twice a year — typically the autumn worming and again before spring grazing
• When buying or borrowing a new horse — clears the most comprehensive range of worms before introducing to your herd
• If faecal egg counts suggest a resistance problem with ivermectin alone
• In broodmares 4–6 weeks before foaling to clear tapeworm and strongyles

Other options in this range

• Equimax — ivermectin + praziquantel, the standard rotation partner
• Equimax Elevation — apple-flavoured Equimax for foals and fussy eaters
• Equimax LV — same actives as Equimax in a smaller-volume syringe
• Strategy-T — oxfendazole + pyrantel, the different-class rotation partner
• Browse the full horse wormer range for boticides, supplements and the rest of the range

Worldwide shipping — no prescription required

We ship Ultimum to the USA, Canada, UK, Europe and worldwide. No vet prescription needed. International tracking included on every order.

Frequently Asked Questions

Q: Is Ultimum the same as Equimax?

A: No — both are made by Virbac but they contain different actives. Equimax uses ivermectin + praziquantel; Ultimum uses moxidectin + praziquantel. Moxidectin is longer-acting and catches encysted small-strongyle larvae that ivermectin misses, which is why Ultimum is the more comprehensive (and more expensive) option.

Q: Why is Ultimum more expensive than Equimax?

A: Moxidectin (the macrocyclic lactone in Ultimum) is more expensive to manufacture than ivermectin, and it kills more parasite life-stages — including the encysted small-strongyle larvae that cause the most damage in adult horses. Used once or twice a year as part of a rotation, Ultimum delivers the broadest single-dose cover available in equine worming.

Q: Can I use Ultimum every worming?

A: Vets generally don't recommend using moxidectin every worming, because it accelerates resistance build-up in the same way over-using ivermectin does. Use Ultimum once or twice a year, alternating with Equimax (ivermectin) and Strategy-T (oxfendazole + pyrantel) for the other rotations.

Q: How often should I worm my horse?

A: Most vets recommend worming adult horses every 8–12 weeks, rotating between drug classes (e.g. Equimax → Strategy-T → Ultimum) to slow the build-up of parasite resistance. Foals are wormed more often (every 4–6 weeks) and pregnant mares should be dosed 4–6 weeks before foaling. Faecal egg counts every 6 months are the most accurate way to fine-tune your worming schedule.

Q: How do I dose by weight?

A: Estimate your horse's weight using a weight tape, a livestock scale, or the bodyweight formula (girth² × length ÷ 11,990). Set the plunger of the syringe to the corresponding weight mark, place the syringe at the back of the tongue and depress. Hold the horse's head up for a few seconds to make sure the paste is swallowed.

Q: Can I worm my pregnant mare?

A: Yes — all the products in this range are safe in pregnant mares when used at label dose. The standard recommendation is to worm 4–6 weeks before foaling, especially with a praziquantel-containing product (Equimax, Equimax Elevation, Equimax LV or Ultimum) to clear tapeworm before delivery.

Q: Why should I rotate between wormers?

A: Equine worms — especially small strongyles (cyathostomins) — develop resistance to single-class wormers when they're used continuously. Rotating between three or more drug classes makes resistance much slower to develop. The textbook rotation is: a macrocyclic lactone (Equimax/Equimax Elevation/Equimax LV/Ultimum) → a benzimidazole + tetrahydropyrimidine (Strategy-T) → back to a macrocyclic lactone. Faecal egg count testing helps you confirm your rotation is still effective.

Q: Are these wormers safe for foals?

A: Equimax Elevation is specifically formulated for foals from 2 weeks of age. Equimax and Equimax LV are safe in foals from 2 weeks of age at the correct dose. Strategy-T and Ultimum are for horses over 4 weeks of age. Always check the label dose for very young foals.

Q: Do I need a prescription?

A: No. All Virbac horse wormers in this range are sold over the counter — no vet prescription required. We ship to the USA, Canada, UK, Europe and worldwide.