Shopping Cart

Call us to order: +44 1352 757777

📦 Free UK Mainland shipping on orders over £80

horse wormer

Which Horse Wormer should I choose?

Worming can be a very confusing subject. People often ask which wormer for my horse? We list here the wormers available on the market by active chemical rather than the trade/brand name.

To answer the question of which wormer for my horse, get used to reading the label to determine which chemical is the active ingredient so that you make the best choice for the parasites you wish to treat. Many different brands contain the same drug.

We recommend the use of regular faecal egg counts to monitor the effectiveness of the horse wormer you use.  You can also ask your vet for a blood test to monitor the effectiveness of your tapeworm control and now there is also a saliva test which appears to be as reliable as the blood test.

There is widespread resistance to pyrantel tartrate, pyrantel pamoate, piperazine and the two benzimidazoles on the market, fenbendazole and oxibendazole.  So checking effectiveness by using worm counts and checking whether you need to worm at all is very important both for the health of your horse and also to ensure the future effectiveness of the wormers on the market.

Which horse wormer is best?

It is difficult to say which wormer is best for horses. Below we list the active ingredients and the horse parasites that they will treat so that the question of which wormer for my horse can be successfully answered.

Active horse wormer Fenbendazole

Fenbendazole Paste 10% is indicated for the control of large strongyles (Strongylus edentatus, S. equinus, S. vulgaris), encysted early third stage (hypobiotic), late third stage and fourth stage cyathostome larvae, small strongyles, pinworms (Oxyuris equi), ascarids (Parascaris equorum), and arteritis caused by fourth stage larvae of Strongylus vulgaris in horses.

Note: In double dose, also approved for removal of encysted forms of small strongyles.

Active horse wormer Ivermectin

Large Strongyles (adults) – Strongylus vulgaris (also early forms in blood vessels), S. edentatus (also tissue stages), S. equinus, Triodontophorus spp. including T. brevicauda and T. serratus and Craterostomum acuticaudatum; Small Strongyles (adults, including those resistant to some benzimidazole class compounds) – Coronocyclus spp. including C. coronatus, C. labiatus and C.labratus, Cyathostomum spp. including C. catinatum and C. pateratum, Cylicocyclus spp. including C. insigne, C. leptostomum, C. nassatus, and C. brevicapsulatus, Cylicodontophorus spp., Cylicostephanus spp., including C. calicatus, C. goldi, C. longibursatus and C. minutus, and Petrovinema poculatum; Small Strongyles – Fourth-stage larvae; Pinworms (adults and fourth-stage larvae) – Oxyuris equi; Ascarids (adults and third- and fourth-stage larvae) – Parascaris equorum; Hairworms (adults) –Trichostrongylus axei; Large-mouth Stomach Worms (adults) – Habronema muscae; Bots (oral and gastric stages) –Gasterophilus spp. including G. intestinalis and G. nasalis; Lungworms (adults and fourth-stage larvae) – Dictyocaulus arnfieldi; Intestinal Threadworms (adults) – Strongyloides westeri; Summer Sores caused by Habronema and Draschia spp. cutaneous third-stage larvae; Dermatitis caused by neck threadworm microfilariae, Onchocerca sp.

Active horse wormer Ivermectin plus praziquantel

Paste provides effective treatment and control of the following parasites in horses. Tapeworms – Anoplocephala perfoliata, Large Strongyles (adults) – Strongylus vulgaris (also early forms in blood vessels), S. edentatus (also tissue stages), S. equinus, Triodontophorus spp. including T. brevicauda and T. serratus and Craterostomum acuticaudatum; Small Strongyles (adults, including those resistant to some benzimidazole class compounds) – Coronocyclus spp. including C. coronatus, C. labiatus and C.labratus, Cyathostomum spp. including C. catinatum and C. pateratum, Cylicocyclus spp. including C. insigne, C. leptostomum, C. nassatus, and C. brevicapsulatus, Cylicodontophorus spp., Cylicostephanus spp., including C. calicatus, C. goldi, C. longibursatus and C. minutus, and Petrovinema poculatum; Small Strongyles – Fourth-stage larvae; Pinworms (adults and fourth-stage larvae) – Oxyuris equi; Ascarids (adults and third- and fourth-stage larvae) – Parascaris equorum; Hairworms (adults) –Trichostrongylus axei; Large-mouth Stomach Worms (adults) – Habronema muscae; Bots (oral and gastric stages) – Gasterophilus spp. including G. intestinalis and G. nasalis; Lungworms (adults and fourth-stage larvae) – Dictyocaulus arnfieldi; Intestinal Threadworms (adults) – Strongyloides westeri; Summer Sores caused by Habronema and Draschia spp. cutaneous third-stage larvae; Dermatitis caused by neck threadworm microfilariae, Onchocerca sp.

Active horse wormer Moxidectin

Strongylus vulgaris – (adults and L4/L5 arterial stages); Strongylus edentatus (adults and tissue stages); Triodontophorus brevicauda (adults); Triodontophorus serratus (adults),  Small Strongyles (adults) Cyathostomum spp., including Cyathostomum catinatum, Cyathostomum pateratum, Cylicostephanus spp, Cylicostephanus calicatus, Cylicostephanus goldi, Cylicostephanus longibursatus, Cylicostephanus minutus; Cylicocyclus spp, including Cylicocyclus insigne, Cylicocyclus leptostomum, Cylicocyclus nassatus; Cylicocyclus radiatus; Coronocyclus  spp., including Coronocyclus coronatus, Coronocyclus labiatus, Coronocyclus labratus; Gyalocephalus, Petrovinema poculatus. Small Strongyles: Undifferentiated lumenal larvae. Encysted cyathostomes: Late L3 and L4 mucosal cyathostome larvae. Ascarids: Parascaris equorum – (adults and L4 larval stages), Pinworms: Oxyuris equi (adults and L4 larval stages), Hairworms: Trichostrongylus axei (adults), Large-mouth stomach worms: Habronema muscae, Horse stomach bots, Gasterophilus intestinalis – (2nd and 3rd instars); Gasterophilus nasalis – (3rd instars).

Active horse wormer Moxidectin plus Praziquantel

Tapeworms – Anoplocephala perfoliata, Strongylus vulgaris- (adults and L4/L5 arterial stages); Strongylus edentatus (adults and tissue stages) Triodontophorus brevicauda (adults); Triodontophorus serratus (adults) Small Strongyles (adults) Cyathostomum spp., including Cyathostomum catinatum, Cyathostomum pateratum; Cylicostephanus spp., including Cylicostephanus calicatus, Cylicostephanus goldi, Cylicostephanus longibursatus, Cylicostephanus minutus; Cylicocyclus spp., including Cylicocyclus insigne, Cylicocyclus leptostomum, Cylicocyclus nassatus; Cylicocyclus radiatus; Coronocyclus spp., including Coronocyclus coronatus, Coronocyclus labiatus, Coronocyclus labratus; Gyalocephalus, Petrovinema poculatus, Small Strongyles: Undifferentiated lumenal larvae, Encysted cyathostomes: Late L3 and L4 mucosal cyathostome larvae, Ascarids: Parascaris equorum (adults and L4 larval stages) Pinworms: Oxyuris equi (adults and L4 larval stages)Hairworms: Trichostrongylus axei (adults), Large-mouth stomach worms: Habronema muscae (adults), Horse stomach bots: Gasterophilus intestinalis – (2nd and 3rd instars); Gasterophilus nasalis – (3rd instars)

Active horse wormer Oxibendazole

Large strongyles (Strongylus edentatus, S. equinus, S. vulgaris); small strongyles (species of the genera, Cylicostephanus, Cylicocyclus, Cyathostomum, Triodontophorus, Cylicodontophorus, and Gyalocephalus); large roundworms (Parascaris equorum); pinworms (Oxyuris equi) including variouslarval stages; and threadworms (Strongyloides westeri).

Active horse wormer Pyrantel Pamoate

Critical (worm count) studies in horses demonstrated that Strongid Paste administered at the recommended dosage was efficacious against mature infections of Strongylus vulgaris (>90%), S. edentatus (69%), S. equinus (>90%), Oxyuris equi (81%), Parascaris equorum (>90%), and small strongyles (>90%).
Note: At double dose, approved for removal of tapeworms (may need to repeat in 2 weeks for best results).

Active horse wormer Piperazine

Control of large and small strongyles, roundworms and pinworms.

Active horse wormer Pyrantel Tartrate

Prevention of Strongylus Vulgaris larval infections; control of adult large strongyles (S. Vulgaris, S. edentatus); adult and 4th stage larvae small strongyles (Cyathostomum species, Cylicocyclus species., Cylicostephanus species. Cylicodontophorus species, Poteriostomum species), Triodontophorus, species; adult and 4th stage larvae pinworms (Oxyuris Equi) and adult and 4th stage larvae ascarids (Parascaris equorum).

More information on which wormer for my horse

All information is taken from the online course on worming by Eleanor M. Kellon VMD.  You can find a link to her website here.

We advise that testing of worm samples is carried out within 5 hours of sampling unless the laboratory is sieving for larvae.  This is because the eggs of small strongyles (red worm) will hatch if the sample is not tested within this time.  If the lab testing the faecal sample do not sieve for larvae and count those as well as eggs then you may have a result which is a false negative for small strongyles.  As small strongyles are so dangerous if they emerge from their encysted form then accurate testing for the adult form is very important.  You should also be sure that the lab carrying out your faecal testing use a centrifuge as part of their testing.

Explore our other articles on horse care & management here.

Free UK shipping

On orders over £80*

Easy 60 days returns

On unopened products

International Delivery

Regular shipping updates

100% Secure Checkout

PayPal / MasterCard / Visa