My lovely wife and I got a dog nearly 4 years ago. Shortly after he joined our family, we noticed the dust levels in the house increased dramatically. It's just one of those effects of having a pet I guess. We toughed it out for several months, dusting several times a week just keep things looking good.
We bought some small air purifiers, which helped quite a bit and kept the air in the house moving, but it didn't solve the problem completely.
What did help dramatically was changing our furnace filter once a month rather than the every three months that is sometimes recommended. We also set the thermostat to run the blower on the system 24-hours a day. This provided a constant air exchange throughout the entire house, and the exchanged air was being filtered non-stop. This made a huge difference in the dust levels in the house. We have to dust way less often now, we breath easier (especially during the winter), and don't wake up with sore throats and stuffed up noses.
Are there any drawbacks? Of course; there's no such thing as a free lunch. First, the cost of changing our furnace filters over the 12-month year tripled. But, the filters we use are only $10-12 a piece, so going from $40 a year to $120, wasn't exactly earth-shattering. Also, theoretically, our electric bill should have gone up slightly, and it likely did, but the extra buck or two goes completely unnoticed on a typically $100 bill.
I also chatted with our furnace repair man about the change and asked him about the added run time shortening the life of the blower. He told me that it likely wouldn't hurt it at all. Many times it's dirt and dust that kill blowers, and we're reducing those levels. And, much like a car's engine, it's easier on the motor's bearings to run constantly, rather than starting and stopping several times a day.
Obviously, there's been some trade offs, but the dust levels in our house are now pretty low, considering the size of our dog, and our indoor air quality is improved as well.
So, if you're battling indoor air quality in your home, consider changing your filter more often and running your forced air blower all the time. It certainly helped clean up our house!