I just did the math on the Zimectrin Gold (1.55% Ivomec, 7.75% Praziquantel) Based on the canine dosage rate of each (Ivomec - .002250 mg/lb and Praziquantel - 2.5mg/lb). The tube is advertised to treat one 1,250 lb horse based on the horse admin. rate of (Ivomec - 91mcg/lb and Praziquantel - 454 mcg/lb). Given this info, we can calculate that the entire tube contains 113.75 mg of Ivomec and 567.50 mg of Praziquantel. The ratio being 4.989
Using a 60lb dog for an example, to treat tapes the dog would need 150 mg of praziquantel (60lbs X 2.5mg). Divide that by our ratio (4.989) and to administer that amount of Praziquantel to the dog would be giving the dog 30.066 mg (or cc's) of Ivomec. A 60lb dog needs .135 cc of Ivomec. (60lbs X .002250 mg/lb).
Based on these calculations, Scott is correct. To treat them properly for the tapes, you would probably kill them on the Ivomec.
Just to reiterate...the dosage you normally give a dog of ivermectin for heart worms/intestinal worm removal is in micrograms...the dosage that you'd be giving your dog to get the required amount of praziquantal in zimectrin gold is in milligrams. 1 milligram (mg) = 1000 micrograms (mcg)
