About Horse Wormers
Horse wormers are antiparasitic treatments designed to kill or control internal parasites including strongyles (redworms and bloodworms), roundworms (ascarids), tapeworms, pinworms, bots and encysted larvae. In Australia, worm burdens are a year-round concern because our climate allows parasites to survive on pasture in most seasons. The key to effective worming is choosing the right active ingredient for the parasites you need to target, rotating chemical groups to reduce resistance, and dosing accurately based on your horse's bodyweight.
Wormers by Active Ingredient
Understanding the active ingredient in each wormer helps you build an effective rotation and ensure you're covering the right parasites at the right time of year.
- Ivermectin (Equimec, Eraquell) - a broad-spectrum wormer effective against roundworms, strongyles, bots, pinworms and lungworm. Does not treat tapeworm. Ivermectin is the most widely used active ingredient in Australian horse wormers and forms the backbone of most rotational programs.
- Ivermectin + Praziquantel (Equimax, Razor) - adds tapeworm coverage to the standard ivermectin spectrum. Use at least twice a year (typically autumn and spring) to cover all three species of equine tapeworm.
- Moxidectin + Praziquantel (Equest Plus Tape) - the longest-acting combination wormer available in Australia, with an egg reappearance period of at least 14 weeks. Moxidectin is also the only single-dose treatment effective against encysted small strongyle larvae, making it an important part of winter and spring worming programs.
- Abamectin + Praziquantel (iO Essential Wormer) - a cost-effective broad-spectrum option covering tapeworm, roundworms, strongyles, bots and summer sores.
- Oxfendazole + Pyrantel (Strategy-T) - a combination wormer using benzimidazole and pyrantel to cover strongyles (including benzimidazole-resistant strains), ascarids, pinworms and tapeworms. Strategy-T does not treat bots.
Seasonal Worming and Rotation
A well-planned worming schedule rotates between chemical groups to slow the development of resistance. While every property and horse is different, a common Australian approach is to worm four times a year, rotating active ingredients across the seasons. Autumn and spring treatments should include praziquantel for tapeworm coverage. A moxidectin-based wormer like Equest Plus Tape in late autumn or winter targets encysted small strongyle larvae that other actives miss. Faecal egg counts (FECs) are a useful tool for tailoring your program, helping you identify which horses carry a high worm burden and which can safely extend the interval between treatments.
Paste, Gel and Pellet Formats
Most horse wormers in Australia come as oral paste in a dial-a-dose syringe, which is the easiest format for accurate dosing. Gel formulations like Equest dissolve rapidly on the tongue, reducing the chance of the horse spitting the dose out. Pellet wormers like Eraquell can be mixed into a small hard feed for horses that resist the syringe, though there is a higher risk of underdosing if the horse doesn't eat the full serve. Whichever format you choose, dose according to your horse's actual bodyweight using a weigh tape or scales rather than guessing.
Worming for Specific Parasites
Some situations call for a wormer chosen specifically for the parasite involved rather than a broad-spectrum rotation product.
- Tapeworm - requires praziquantel. Found in Equimax, Razor, Equest Plus Tape, iO Essential and Strategy-T. Treat at least twice yearly.
- Bots - ivermectin, moxidectin and abamectin all treat bots. Time your bot treatment for after the first frost (or late autumn in warmer regions) when bot flies have stopped laying eggs.
- Encysted small strongyles - only moxidectin (Equest) is effective as a single dose against encysted larval stages. This is a critical treatment, typically given in winter, because encysted larvae can cause severe damage when they emerge from the gut wall in spring.
- Pinworms - ivermectin, oxfendazole and pyrantel all treat pinworms. If your horse is rubbing its tail, a faecal egg count can confirm whether pinworms are the cause.
Dosing and Safety
Accurate dosing is essential for both effectiveness and safety. Underdosing fails to kill all parasites and accelerates resistance. Overdosing wastes product and can cause adverse reactions, particularly with moxidectin in foals and smaller breeds. Use a weigh tape to estimate bodyweight and set the syringe dial accordingly. Most paste wormers are safe for pregnant mares, breeding stallions and foals from 6 to 8 weeks of age, but always check the label for specific age and weight restrictions. Equest (moxidectin) requires particular care in foals and horses under 400 kg.
Common Questions About Horse Wormers
Below you can see common questions we get asked about this topic.
How often should I worm my horse in Australia?
Most veterinarians recommend worming four times a year as a baseline, with treatments timed to seasonal parasite activity. Faecal egg counts can help you refine the schedule for individual horses, as some carry higher burdens than others. At minimum, include a moxidectin treatment in winter for encysted larvae and praziquantel at least twice a year for tapeworm.
What is the best horse wormer in Australia?
There is no single best wormer because effective parasite control relies on rotating between chemical groups. Equimax (ivermectin + praziquantel) is a popular broad-spectrum choice for routine treatments. Equest Plus Tape (moxidectin + praziquantel) is the strongest single-dose option and the only wormer effective against encysted small strongyle larvae. Strategy-T covers strongyles, ascarids and tapeworm using a different chemical group for rotation.
What is the difference between ivermectin and moxidectin horse wormers?
Both are macrocyclic lactones, but moxidectin has a longer egg reappearance period (14+ weeks vs 8 weeks for ivermectin) and is the only active ingredient effective as a single dose against encysted small strongyle larvae. Moxidectin is typically reserved for one or two treatments per year within a rotation program rather than used at every worming.
Can I buy horse wormers online in Australia?
Yes. Horse wormers are available without a prescription in Australia and can be purchased online. We ship all wormer products Australia-wide with same or next-day dispatch.
Do I need to do a faecal egg count before worming?
Faecal egg counts are not mandatory but are increasingly recommended by vets as part of a targeted worming approach. An FEC tells you how many worm eggs your horse is shedding, which helps you decide whether a treatment is needed and whether your current worming program is working. They're particularly useful for reducing unnecessary treatments and slowing the development of wormer resistance on your property.
