Zerofen is a broad spectrum wormer for the control of mature and developing immature forms of the following major species of roundworm in sheep and cattle.  


In sheep it is effective against benzimidazole susceptible strains of the following parasites:

Gastro-intestinal roundworms:  Ostertagia, Haemonchus, Trichostrongylus, Nematodirus, Cooperia, Oesophagostomum, Chabertia, Bunostomum and Strongyloides species. Lungworms:  Dictyocaulus filaria. It is usually effective for the control of tapeworms, Moniezia spp, in sheep.  May be useful for the control of Trichuris in sheep.


In cattle it is effective against the following parasites: 

Gastro-intestinal roundworms:  Ostertagia, Cooperia, Trichostrongylus, Nematodirus, Haemonchus, Oesophagostomum, Bunostomum, Strongyloides and Trichuris species. Lungworms:  Dictyocaulus             viviparus. It is usually effective against inhibited larvae of Ostertagia species in cattle. Has an ovicidal effect on nematode eggs.


Active Ingredient: Fenbendazole


Withdrawal:  Sheep 21d Meat Withhold

Cattle 14d Meat Withhold

132 hours Milk Withhold.  The product must not be used in sheep producing milk for human consumption.


Pack Sizes:  1ltr, 2.5ltr & 10ltr

Zerofen 10% Oral Drench

  • Dosage

    Cattle: 1 ml per 13 kg bodyweight

    Cattle over 400 kg should be given a further 5 ml for each additional 65 kg bodyweight.

    Sheep:  1 ml per 20 kg bodyweight

    Sheep over 80 kg should be given a further 0.5 ml for each additional 10 kg bodyweight.

  • Legal Catagory


  • IMPORTANT - Animal Medicines

    When purchasing animal medicines such as wormers, that are classified as POM-VPS  (prescription only medicine), it is a legal requirement that you to complete a short form, prior to dispatch, to enable us to correctly prescribe your product.  Failure to fully complete the form may result in a delay of your goods being dispatched.

    One of our Animal Health specialists will contact you if there are any queries. 
    Click Here to complete and submit your form


Registered Address   90 The Broadway, Chesham, Buckinghamshire. HP5 1EG