Summer vacations may have investors wondering if the time is right to buy dividend stocks, but sitting on the sidelines because of third-quarter doldrums may not be your best bet. Dividend investors are likely better served by taking a long view that allows dividends to offset Wall Street's seasonal swings.

That could be particularly true for health-care stocks Amgen (NASDAQ:AMGN), Healthcare Services Group (NASDAQ:HCSG) and Quality Systems (NASDAQ:NXGN). All three companies address growing markets, and all three are historically strong performers in third quarter (which just started).

In the following slideshow, you'll learn more about these three dividend paying companies and the reasons behind why you may want to include them in your portfolio.