This is where you need a vet who is knowledgeable about breed responses to medications. BCs, aussies, and similar breeds and mixes happen to be sensitive to one of the the active ingredients in Heartgard and some other brands - ivermectin. Although the dose is very low in these meds and some owners do use them with no problem, many owners prefer to use a med with a different active ingredient.
Interceptor or Sentinel are generally recommended heartworm preventatives for these breeds because they do not contain ivermectin. They aren't equivalent to each other because they use different ingredients. They tend to be more expensive. Some vets consider that either one does a better overall job compared to the ivermectin products so they do recommend them ahead of the others for all breeds.
Your vet should explain all this to you so you can make an informed decision.
However, I do have to say that something here confuses me. I don't know where you are located, but generally you need a prescription from a vet to purchase heartworm preventatives. When you went in to get the prescription, why didn't you get a supply at that time if time was tight? Just curious.
Interceptor or Sentinel are generally recommended heartworm preventatives for these breeds because they do not contain ivermectin. They aren't equivalent to each other because they use different ingredients. They tend to be more expensive. Some vets consider that either one does a better overall job compared to the ivermectin products so they do recommend them ahead of the others for all breeds.
Your vet should explain all this to you so you can make an informed decision.
However, I do have to say that something here confuses me. I don't know where you are located, but generally you need a prescription from a vet to purchase heartworm preventatives. When you went in to get the prescription, why didn't you get a supply at that time if time was tight? Just curious.
