Do I use Heartworm preventative medication?

Dr. Charles Salemi

Charlie Salemi, D.V.M. – Oasis Team member since 2009

Several times a week, veterinarians always get the question, “What would you do if this was your dog (or cat)?” Lately that question has been referring to the use of heartworm preventatives, especially Heartgard.

Heartworm disease is in our area

A few years ago, I would likely say that Arizona was not an area where heartworms are prevalent and that monthly treatment was not absolutely necessary. That has now changed. In the last 3 months (early 2012) here at Oasis, we have seen 3 cases of heartworm disease with 2 of the dogs having never been outside of Maricopa County.

The Mosquitoes are in our area

In humans, the reported cases of West Nile Virus contracted in the Chandler area is increasing, which means the mosquito population is here and it is spreading disease. Everyone is now hearing about the emerging threat of Zika virus as well.The same mosquito vector can transmit heartworm disease. It only takes one mosquito biting an infected dog to then spread heartworm to dozens of other dogs.

Therefore, it is my current recommendation that ALL dogs be on heartworm preventative. With Heartgard, you also get a broad spectrum dewormer to help keep your dog parasite-free. So now when people ask if it were my dog, I say “Yes”, and in fact my dog, “Stanley” gets his Heartgard chew every month and I do test him annually for heartworm disease. If you have any questions about Heartgard, or Heartworm disease, please feel free to email me at

Dr. Charlie

(updated by Dr. Tenney 3/31/2016)


  1. Gary Anderson says

    Hello, I live in New River, Az. I am in the desert. I have been giving my blue heeler Iverhart Plus once a month. But in researching this subject, I am wondering if it is necessary to continue this medication. My local Vet says it is up to me. I am not a doctor.
    My dog does not leave the state. Can I get your thoughts on this? Thanks, Gary