Each capsule contains 170mg Praziquantel for removal of all species of Tapeworms in dogs of 60 pounds or greater. 1 capsule per treatment is generally all that is needed in large dogs, but giant breeds may be given an additional capsule for every 60 pounds of weight if needed. In nearly all cases a single treatment of one capsule is all that is needed until re-infestation. Effective within approximately 24 hours or less. The drug allows absorption of the tapeworms so you will no longer see them in the dogs stool if you were seeing any tapeworm segments being shed. Praziquantel is the only drug effective in killing the Common Tapeworm, which is commonly contracted in dogs by accidentally swallowing as few as one flea containing tapeworm eggs. Tapeworms rob a dog of nutrients for approximately 3 weeks before any signs of infestation are seen, such as segments of the tapeworm shed in the dogs stool (they look similar to a grain of white rice), dogs dragging their butt on the ground, or licking/biting at their belly (which can also indicate fleas). Some owners prefer to treat for tapeworms only when signs of infestation are seen, while others prefer to treat monthly. The choice is yours. Prazi-Rid is a very affordable option compared to up to $30 or more per dose from local pet supply stores or veterinary visits.