Written by Dr. Brenda Gough
Q. WHY DO I HAVE TO TEST FOR HEARTWORM WHEN MY DOG LIVES IN AN APARTMENT?
Heartworm is transmitted by mosquitos. Mosquitos are everywhere! Simple as that! At least once every other year we are faced with a little apartment dog who is positive for heartworm, who barely left the building. These poor little dogs don’t do well with the treatment for heartworm, so it is far better to prevent than to be faced with expensive, difficult treatments.
Q. WHY DO I HAVE TO DO THE PREVENTION? WON’T I BE ABLE TO TELL WHEN MY DOG HAS IT?
From the time your dog gets infected with heartworm, it takes around two years before there are any clinical signs. The clinical signs are consistent with heart failure. So by the time your dog is clinical for heartworm, it could be too late to do anything about it and you may be faced with euthanizing your pet. If we prevent the disease, we keep this from happening, and we also help prevent the spread of the disease to others. Think about it – if your dog is infected, and it’s two years before you figure it out, that is a ton of mosquitos that are now spreading the disease to others in the area.
Q. WHY NOT JUST TEST YEARLY, AND TREAT IF MY DOG BECOMES POSITIVE?
If your dog is positive for heartworm, the treatment is a derivative of arsenic. It has to be given by deep intramuscular injection into the muscles of the back. It’s very painful. There is often swelling at the injection site. While they can survive the treatment, you still are faced with keeping your dog perfectly quiet for an entire 6-8 weeks after the treatment, while the dead worms are dissolving inside the heart. If your dog gets excited, the dead worms dislodge and end up floating through the bloodstream into the lungs or the brain, triggering clinical signs that resemble stroke or anaphylactic shock. So the treatment, while many dogs survive it and go on to do very well, is pretty hard on the system. It’s far better for your dog if you just prevent the disease!
Q. WHY DO I HAVE TO TEST YEARLY, IF MY DOG IS ON THE PREVENTION?
No medication is 100 percent effective, even if given exactly as prescribed. Heartworm preventatives are very, very effective, close to 95% or higher, but that’s still 5 dogs out of 100 who are on the medication but it didn’t work for them. Even aspirin is only 40% effective. They are excellent products thoroughly tested and researched, but still not perfect. Then you have to factor in owners being on top of prevention, every month on the same day. I would LOVE to think that all of you give the medicine on time, every time, but the reality is that life sometimes gets in the way and you miss a dose or are late on a dose, and that opens up a window for the bug to take over.
So the long and short of it is this – test your dog every year, make sure they get the prevention on time, and don’t kid yourself: mosquitos are EVERYWHERE!!