We have used injectable cattle dewormer on horses since it first came out in 1979. We DO NOT inject it but just squirt it in the back of a horse's mouth. We can buy a 500cc bottle of it from the Livestock Supply places for less than $100.00 and see no reason to spend more money on the same active ingredient. We have much less of it spit out than when horses are given the little tubes of paste and we can dose it much more accurately because we only draw as much onto a 12cc syringe as the horse needs.
I was just curious how many other people do the same thing?