Fenbendazole is an antiparasitic drug which is not recommended for use in avian species due to its toxicity. There are much safer alternatives available. When it is used, it's beneficial for the control of gastrointestinal parasites such as roundworms (Ascaridia galli
, Heterakis gallinarum
), lungworms, gapeworms (Syngamus trachea
) and tapeworms (Railletina spp
). Despite being widely used as a dewormer in many species, toxicity has been reported, particularly in birds.
Fenbendazole comes available as an oral suspension. It can be given orally via feed, drinking water, or syringe, depending on the form and concentration.
Fenbendazole shouldn't be given to birds actively growing new feathers, such as those in the early stages of growth or during molting.
Follow instructions by manufacturer over what is provided below.
- Waterfowl: 5-15 mg/kg, given orally once a day for 5 days.
- Chickens: 15-20 mg/kg given orally once a day for 3 days is needed to treat Ascaridia galli, Heterakis gallinarum, Syngamus trachea, and Railletina spp. For Ascaridia galli and Heterakis gallinarum, only 1 mg/kg BW (0.454 mg/lb) is needed for 5 consecutive days.
Egg Withdrawal: FARAD recommends an egg withdrawal interval of 17 days for hens.