Heartworms are one of the worst diseases you dog can acquire, says dogheartworm.org. Recovering from this disease takes time and a plan of drugs from your veterinarian, plus the care and immune system boosting from the owner.
The best plan of attack is to never let it happen.
But how effective are the preventatives that have been used for decades now? Not as good as you think, according to The Whole Dog Journal. There is now plenty of evidence to show that even the market's best preventative will not work on a strain of heartworms that has built up resistance to the preventative medicine.
There is also evidence showing that the most popular preventative, Heartgard, is not 100 percent effective, despite their label stating that claim. 100 percent means just that, not 99 percent or 98 percent. The U.S. Food and Drug Administration's Center for Veterinary Medicine has sent letters to Heartgard's manufacturer, asking them to remove the false claim, according to Whole Dog Journal.
One scenario starts with the evolution of the heartworm. If a dog has heartworm, that means it has adult-form heartworms. Adults multiply in record numbers and have tiny little microfilaria, a juvenile stage, that can transmitted to the next dog when a mosquito bites the infected dog and picks up the worm.
The preventative's job is to kill the microfilaria and other juvenile stages, before they have a chance to become adults. But as parasitology experts have predicted for years, the slow kill method can lead to resistance. This is not unlike the antibiotic resistances common with humans.
When the preventative is given, it is up against hundreds of millions of this tiny little microfilaria. So it is not far-fetched to think that one or two even can have a strong enough immunity to slide through this phase, according to dogster. At this point, they turn into larvae, and then adult heartworms that produce nothing but resistant microfilaria, which is exactly what has been found in the Mississippi Basin region.
So what do you do? Remember that this is an isolated strain of heartworm, there are plenty more that the preventatives do work to eliminate. Be proactive about this disease, it is in your pet's best interest to steer clear of heartworms, so keep up your preventative routine.
