What: Shares of specialty retailer Boot Barn (NYSE:BOOT) slumped on Wednesday following the company's second fiscal quarter report. While total revenue grew rapidly because of new store openings, same-store sales disappointed, sending the stock down about 13% by 11:45 Wednesday morning.

So what: Boot Barn reported quarterly revenue of $129.7 million, up 50% year over year. This growth was driven almost solely by the addition of new stores. Boot Barn acquired Sheplers earlier this year, and the company has opened 25 new stores over the past four quarters. Same-store sales rose by just 0.1% during the quarter, with negative comps at Sheplers stores bringing down the average.

Non-GAAP EPS came in at $0.04, down from $0.08 during the same period last year and in line with analyst expectations. On a GAAP basis, Boot Barn posted a loss of $0.13 per share, down from a gain of $0.05 per share during the second quarter of last year. Higher interest expense and a 56% year-over-year rise in operating expenses drove down the company's profitability.

One particular problem for the company has been the rapid decline in oil prices over the past year. In Boot Barn's 15 stores that directly serve areas where the oil industry is prevalent, same-store sales have turned negative, with North Dakota, Wyoming, and Colorado bearing the brunt of the impact.

Now what: Boot Barn does expect things to improve over the next couple of quarters. For fiscal 2016, which ends in March, the company expects same-store sales to grow by a low-single-digit percentage, and during the third quarter, Boot Barn expects its Sheplers business to grow by a mid-single-digit percentage.

Boot Barn did slash its earnings guidance for the full year, however, which is likely the main driver behind the drop in the stock price today. Boot Barn now expects non-GAAP net income of between $0.76 and $0.80 per share for the full year, down from a previous outlook of $0.85 to $0.90 per share. Non-GAAP earnings exclude costs related to merger integration and other one-time expenses, so the guidance cut can't be blamed on the Sheplers acquisition.

Boot Barn now operates 201 stores, and with the company expecting to open 22 new stores in total this year, revenue growth won't be a problem. But trouble in the oil industry is hitting the company hard, and investors punished the stock for the cut in earnings guidance.

Timothy Green has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.