The Edmond Sun

October 29, 2012

Injectable six-month heartworm preventative a good deal

Dr. M. Margaret King
The Edmond Sun

EDMOND — Q:  I was visiting with my neighbor about our respective dogs.  She mentioned a shot that can be given for preventing heartworm disease that lasts for six months.  Is this effective and is it safe to use?  It would be so much easier than having to remember to give a pill every month.  Can you discuss the pros and cons?

A: ProHeart 6 is indeed an injectable parasiticide that is given to dogs for the primary purpose of preventing heartworm disease.  It is given every six months and can be used in dogs six months of age and older.

In addition to preventing heartworms for six months, it effectively treats two species of the intestinal parasite most commonly seen in our pet dogs, hookworms.

It has been used safely with other products commonly used to treat our canine friends such as non-steroidal anti-inflammatory drugs or NSAIDS, other antiparasitcides such as those used to treat fleas.  It also has been used concurrently with antibiotics, steroids, analgesics and various anesthetics.

ProHeart 6 has been shown to be effective for the full six months as labeled.  When measured in the canine body, it does not accumulate over time with repetitive use.

Heartworm disease is definitely on the rise in this country.  It is so very important to use a preventative year-round, especially here in Oklahoma.  The extra protection it offers in preventing hookworms is an important bonus.  

Hookworms and heartworms also can affect our feline friends as well as us.  Having a heartworm positive dog in the backyard or house provides a reservoir for mosquitoes to feed on and share the disease around.

Your veterinarian has to receive special training from the manufacturing company in the form of a webinar to purchase and use this product.  He/she will be an excellent source of information about the use of ProHeart 6 in your pet.  You should discuss the pros and cons and then make the best decision for you and your pet.

As with all drugs there can be some side effects in certain pets.  Allergic reactions can happen with any substance given that is foreign to the body.  Other possible side effects are listed and should be discussed with your veterinarian prior to its use.

Giving the injection at a time you can watch your pet for the first 24 hours, especially the first time it is given, is wise.  You are certainly correct in saying it will be more convenient than having to remember a monthly pill.

Discuss it with your veterinarian and make an educated decision for your pet.  It is indeed a very effective and long-lasting solution in the prevention of heartworm disease.

You also can visit the website at or call the company, Pfizer, at 1-800-366-5288 to get a product overview to take to your veterinary visit.


DR. M. MARGARET KING, a longtime Edmond veterinarian, is a guest columnist. If you have any questions for her, email them to