Important note:
I am the compiler of the PoultryPedia.com website & there may be a mistake in the dose amount I listed. I am suspecting I misinterpreted something to come up with the "1-5 ccs orally" dose.
I am currently researching this & will post verified info as soon as I can locate more. I am very sorry for any problem this likely mistake may have caused!!! I try to post reliably accurate information, & apologize if this was a mistake. I will update more within the next few days.
Although my research is w/o error, I've no ability to verify the accuracy of the informations obtained. However, the following may be of use to you ... among the reasons you're having difficulties may be the fact that the FDA has not aproved this drug for the treatment of roundworms in poultry.
Fenbendazole belongs to a class of drugs known as anthelmintics.
Veterinary formulations: Panacur
(Hoechst), Safe-Guard
(Hoechst)
Fenbendazole is available in 222 mg/gram granules, 222 mg/gram suspensions and 100 mg/gram pastes.
FDA prohibits extra-label drug use in feed; therefore all treatments must be administered via drinking water.
Follow all manufacturer recommended doses.
Consult your veterinarian for prescriptions and withdrawal times.
Table 2: Extra-Label Drugs Used for Treatment of Intestinal Worms via Drinking Water
http://www.healthybirds.umd.edu/disease/deworming birds.pdf
Fenbendazole, of the Cattle Safe–Guard brand, for Roundworms, Capillaria, cecal.
http://www.healthybirds.umd.edu/Dis...ication Programs fro Small Poultry Flocks.pdf
Dosage information for 'Other worms'
Fenbendazole
1 oz Safeguard or Panacur per 15-20 lb (Safeguard) feed for 1 day or 1.2 oz/100 lb of feed for 3 (Panacur) days. Dissolve the fenbendazole product in one cup of water. Mix this solution well into the feed and give to the birds as their only feed source.
The Merck Veterinary Manual [excerpt]
Home : Pharmacology : Anthelmintics : Benzimidazoles
http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/191507.htm
Mebendazole, flubendazole, and fenbendazole can be used effectively against nematodes of the GI and respiratory tracts of birds.
PubMed [excerpt]
The effects of benzimidazoles on the larval stage of Toxocara cati in experimentally infected chickens.
http://www.ncbi.nlm.nih.gov/pubmed/19696725
It is possible that poultry reared outdoors and feeding in open range system, gain Toxocara eggs from soil and or by eating infected earthworms as paratenic host. The aim of the present study was to investigate the effects of albendazole and febendazole in experimentally infected chickens with eggs of T. cati by histopathological and digestive methods. Pathologic lesions were observed only in the untreated group and larvae were detected in brain of 3 chickens of this group by squash method. No larva was observed at histopathological level in liver, lungs, brain, cardiac and skeletal muscles and other examined organs of either treated or untreated animals. No lesion was seen in other tissues of the infected untreated chickens. Treatment resulted in disappearance of the larvae and disappearance of the gross and histopathologic abnormalities from their organs. No detectable difference was observed in chemosusceptibility of the two drugs.