Merck Animal Health Safe-Guard Dewormer Paste contains the active anthelmintic, fenbendazole. The chemical name of fenbendazole is methyl 5-(phenylthio)-2-benzimidazole carbamate. Each gm of Safe-Guard Paste 10% horse and cattle wormer contains 100 mg of fenbendazole and is flavored with artificial apple-cinnamon liquid. The cattle and horse dewormer's antiparasitic action is believed to be due to the inhibition of energy metabolism in the parasite.

• Horse Indications: Safe-Guard Paste 10% is indicated for the control of large strongyles (Strongylus edentatus, S. equinus, S. vulgaris), encysted early 3rd stage (hypobiotic), late 3rd stage & 4th stage cyathostome larvae, small strongyles, pinworms (Oxyuris equi), ascarids (Parascaris equorum) & arteritis caused by 4th stage larvae of Strongylus vulgaris in horses
• Approved for use concomitantly with an approved form of trichlorfon; trichlorfon is approved for the treatment of stomach bots (Gasterophilus spp.) in horses
• Refer to the manufacturer's label for directions for use & cautions for trichlorfon
• Beef and Dairy Cattle Indications: Safe-Guard Paste 10% is indicated for the removal and control of Lungworm (Dictyocaulus viviparus); Stomach worms: (Haemonchus contortus, Ostertagia ostertagi, Trichostrongylus axei); Intestinal worms: (Bunostomum phlebotomum, Nematodirus helvetianus, Cooperia punctata & C. oncophora, Trichostrongylus colubriformis, Oesophagostomum radiatum)
• Contraindications: There are no known contraindications for the use of Safe-Guard Paste 10% in horses or cattle
• In dairy cattle, there is no milk withdrawal period
• Treats 8 animals of 500 lb. each
• Net Wt. 3.2 oz. (92g)
• Horse Dosage: Safe-Guard Paste 10% is administered orally at a rate of 2.3 mg/lb. (5 mg/kg) for the control of large strongyles, small strongyles & pinworms
• Each mark on the plunger rod corresponds to a dose of 5 mg/kg (2.3 mg/lb.) for 250 lb. body weight
• For foals & weanlings (less than 18 months of age) where ascarids are a common problem, the recommended dose is 4.6 mg/lb. (10 mg/kg) or 2 marks will deworm a 250 lb. horse
• For control of encysted early 3rd stage (hypobiotic), late 3rd stage and 4th stage cyathostome larvae & 4th stage larvae of Strongylus vulgaris, the recommended dose is 4.6 mg/lb. (10 mg/kg) daily for 5 consecutive days; administer 2 marks for each 250 lb. body weight per day
• Beef and Dairy Cattle Dosage: Safe-Guard Paste 10% is administered orally at a rate of 2.3 mg/lb. (5 mg/kg) or 11.5 g Safe-Guard (fenbendazole) Paste for 500 lb. body weight (227 kg)
• Under conditions of continuous exposure to parasites, retreatment may be needed after 4 - 6 weeks
• Precautions: Horse: Side effects associated with Safe-Guard Paste 10% could not be established in well-controlled safety studies in horses with single doses as high as 454 mg/lb. (1,000 mg/kg) and 15 consecutive daily doses of 22.7 mg/lb. (50 mg/kg)
• At higher dose levels, the lethal action of fenbendazole may cause the release of antigens by the dying parasites, which may result in either a local or systemic hypersensitive reaction varying in severity from itching or a rash to increased respiration and collapse. A veterinarian should be consulted if this type of reaction is suspected.
• Safe-Guard Paste 10% has been evaluated for safety in pregnant mares during all stages of gestation with doses as high as 11.4 mg/lb. (25 mg/kg) and in stallions with doses as high as 11.4 mg/lb. (25 mg/kg)
• No adverse effects on reproductivity were detected. The recommended dose for control of 4th stage larvae of Strongylus vulgaris, 4.6 mg/lb. (10 mg/kg) daily for 5 consecutive days, has not been evaluated for safety in stallions or pregnant mares
• Internal Parasites: Regular deworming at intervals of 6-8 weeks may be required due to the possibility of reinfection