The other ingredient in the Z-Gold does kill tapes and does it very well.
The problem is, as mentioned, that to get an efficacious dose of the praziquantel, you overdose on the Ivermectin. The Ivermectin has a very wide "safe" dosage window, as in when it is used for mange, etc, but why risk it?
I used Abendazole (Valbazen) prophylactically for a while, but decided I was wasting time, money and the slight risk of side effects to the dogs. Nowadays, I just watch them like a hawk and keep Flagyl and Drontal Plus on hand.
IMHO, everyone out to keep Flagyl on hand.... nothing spoils a trip out of town like a dog with explosive, green,