Control Strongyles in Horses, Horse Dewormer

A: Worma Drench (Oxfendazole 100 g/L) is a broad spectrum oral anthelmintic for horses and cattle (dairy & beef). In horses, it is used to control mature & immature stages of Bloodworm (Strongylus vulgaris); Large strongyles or Redworms, Large Roundworm, Pinworms and Small strongyles. In cattle, it is used to control barber's pole worm, small brown stomach worm, small intestinal worm, stomach hairworm, thin necked intestinal worm, hookworm, nodule worm, lungworm and cattle tapeworm. Administer orally with accurate drenching equipment, disposable syringe, stomach tube, or by mixing thoroughly into the feed.

A: Tapeworm eggs are not routinely found in faecal egg counts even when tapeworms are present within the horse. Blood and saliva tests have been developed and are available in Europe and USA.

Most horses with tapeworms exhibit no signs or symptoms. The most commonly reported sign associated with tapeworm infection is colic associated with irritation to the section of the large intestinal called the caecum which can lead to an intussusception.

A: Due to increasing worm resistance to commonly used wormers, interval dosing every 6-8 weeks is now strongly discouraged. The frequency of “worming” for your horse should be based on faecal egg count results and consultation with your veterinarian to ensure you are using the most appropriate worm control strategy for your horse.

As anthelmintic resistance continues to grow, the implementation of non-chemical control of worms is becoming more and more important. These strategies include pasture rotation, picking up manure and the use of biological treatments such as BioWorma.

A: Wormers that are advertised as “broad spectrum” with “tape” usually contain a “mectin” (ivermectin, moxidectin, abamectin) plus either praziquantel, morantel or pyrantel eg. MecWorma & Tape. These dual actives can treat small strongyles, large strongyles, pinworms, roundworms, tapeworms and bots.

A: Since some horse worms do not show up on routine faecal egg counts eg. Pinworms and tapeworms, many horses are wormed with a product that is effective against tapeworms in autumn (+/- spring) regardless of their faecal egg count result when these worms will be at their peak within horses. MecWorma®& Tape contains morantel tartrate that is effective against the most common intestinal tapeworm in horses (Anoplocephala perfoliata).

A: The best wormer for your horse will be based on your horses’ age, environment, previous worming history and faecal egg count status.

A: Wormer choice should be based on faecal egg count results and in consultation with your veterinarian.

Foals are particularly at risk of roundworm (ascarid) infections. Research on horse properties around world have found widespread resistance. Dual active wormers that include morantel e.g., MecWorma & Tape or a BZ class of wormer e.g. Worma Drench or Worma Paste are generally the best options, but the decision should be based on faecal egg count results and previous faecal egg count reduction tests.

Roundworms can cause significant illness in foals including pneumonia, peritonitis, and impaction colic. Faecal egg reduction tests should be performed to confirm that resistance has not developed on your property to any wormer active.

A: Most “wormers” that are registered for use in horses are safe to use in foals from 6 weeks of age (please read product label prior to administration). However, the choice of wormer is very important as foals, weanling and yearlings are uniquely at risk of roundworm (ascarid) infections.

Dual active wormers that include morantel or pyrantel eg. MecWorma & Tape or a BZ class of wormer eg. Worma Drench or Worma Paste are generally the best options for foals. However, wormer choice should be based on faecal egg count results and in consultation with your veterinarian.

Due to the ever-increasing incidence of anthelmintic resistance, faecal egg count reduction tests should ideally be performed 2 weeks after de-worming to confirm that resistance has not developed on your property to a particular wormer active.

A: Morantel tartrate and pyrantel embonate are effective against tapeworm - Anoplocephala perfoliata. Praziquantel is effective against Anoplocephala perfoliata, Anoplocephala magna and Paranoplocephala mammillana. MecWorma®& Tape contains morantel tartrate and is effective against the most common intestinal tapeworm in horses (Anoplocephala perfoliata).

A: The best wormer for your horse will be based on your horses’ age, environment, previous worming history and faecal egg count.

There is known resistance of small strongyles to the Benzimidazoles (BZ) class of anthelmintics and as such horses with high faecal egg counts are generally recommended to use a macrocyclic lactone (ML) class of anthelmintic (i.e. ivermectin, abamectin, moxidectin) with or without a tetrahydropyrimidine (THP) (i.e. Pyrantel, Morantel) such as MecWorma & Tape or MecWorma & Bot.

Veterinary advise should be sort when choosing the correct wormer and given the increasing resistance of strongyles to “wormers” (anthelmintics), faecal egg count reduction tests should be regularly performed to confirm the efficacy of any chosen “wormer” for your property.