Dollar Tree is slashing its full-year earnings and sales forecasts as its customers continue to struggle with higher prices and spend less.

Shares tumbled more than 10% before the opening bell Wednesday after hitting a 52-week low on the prior day. Less than a week ago, shares of rival bargain chain Dollar General had their biggest one-day decline ever after a dismal quarter.

Dollar Tree said that it now expects full-year adjusted earnings between $5.20 and $5.60 per share. Its prior outlook was for $6.50 to $7 per share.

The Chesapeake, Virginia, company also projected annual sales in a range of $30.6 billion to $30.9 billion, down from $31 billion to $32 billion.

Analysts polled by FactSet expect full-year earnings of $6.56 per share on revenue of $31.17 billion.

Dollar Tree has been trying to lure customers from other retailers with rock-bottom prices, but juggernauts like Walmart and Target have also said their customers are under pressure and they're cutting prices, too.

Dollar Tree's second quarter revenue was $7.38 billion. Its adjusted revenue was $7.37 billion, which is short of the $7.5 billion that analysts surveyed by Zacks Investment Research expected.

Dollar Tree earned $132.4 million, or 62 cents per share, for the period ended Aug. 3. Stripping out certain items, earnings were 67 cents per share, which fell far short of Wall Street expectations of $1.03 per share.

Chief Financial Officer Jeff Davis said in a prepared statement that the company's per-share earnings came up short partly due to the economic pressure on its middle- and higher-income customers. Last week, Dollar General said it was its lower-income customers that were feeling the most pressure.

Dollar Tree Chief Operating Officer Mike Creden said during the company's conference call early Wednesday that financial pressures are spreading upward to higher-earning customers.

"Dollar Tree has a broader customer base that includes more middle and upper-income households and beginning this quarter, we started to see inflation, interest rates, and other macro pressures have a more pronounced impact on the buying behavior of these customers," Creden said.

Even though inflation is slowing, many Americans remain unhappy with today's sharply higher prices for such necessities as gas, food and housing compared with their pre-pandemic levels. Many have cut spending on nonessentials to save money for things like groceries.

For the third quarter, Dollar Tree anticipates adjusted earnings between $1.05 and $1.15 per share, with revenue in a range of $7.4 billion to $7.6 billion. Analysts polled by FactSet expect earnings of $1.31 per share on revenue of $7.58 billion.