Zimectrin for dogs

Question
I was looking for a less expensive way to protect my dogs from heart worms, fleas and ticks. they are also very skin sensitive. Using Z for my dogs is a good idea; I have horses, too, and have to get it anyway. Does it matter if it is Zimectrin or Zimectrin Gold? But use only 1cc/1ml of the paste? Also, I want to get a handle on the fleas and ticks, and other skin problems. Can you help?? Thank you so much!!

Answer
I am not familiar with Zimectrin.  Is it another brand of ivermectin?  My Heartgard+ for 26-50 pound dogs contains 136 mcg of it.  The gold likely means it has other ingredients, such as the pyrantel in the Heartgard+.  If so, it should be Ok for your dog.  There are a number of good flea and tick products.  The cheapest of the effective ones may be Bio Spot.  Since I have an old dog with a flea allergy, I switch to Revolution in the flea season.  This is my fourth summer without any trouble using it.  I can't prove I would have trouble without it.  It is expensive.