The stock price for Idexx Laboratories Inc. reached an all-time high on Friday after the Westbrook company reported first-quarter revenue of $417.6 million, up 9 percent from a year earlier.

Idexx shares trade on the Nasdaq exchange under the symbol IDXX. The stock closed at an all-time high of $84.35 on Friday, up 4.4 percent from the previous day’s close.

Idexx reported net income of $46 million, or 51 cents a share, for the quarter, compared with $46.6 million, or 49 cents per share, in the first quarter of 2015. The company had nearly 5 million fewer outstanding shares in the first quarter compared with a year earlier, which boosted the earnings attributed to each share.

Idexx said the continued negative impact of changes in foreign currency exchange rates cut into the veterinary technology firm’s earnings per share, which were up 4 percent from the first quarter of 2015. The company said earnings per share would have risen 14 percent if exchange rates had not been unfavorable.

However, Idexx said the exchange rates are becoming more favorable. It upwardly adjusted its earnings expectations for the full year to a range of $2.18 to $2.25 per share, with revenue in the range of $1.73 billion to $1.75 billion.

Another factor that helped increase earnings per share was savings from a federal research and development tax credit, which benefited the current but not the prior year’s first quarter, the company said. The tax credit had a favorable impact of 2 percent, it said.

Both the revenue and earnings per share reported by Idexx beat Wall Street analysts’ expectations. Five analysts surveyed by Zacks Investment Research estimated the company would achieve revenue of $404.6 million and earnings of 46 cents per share in the first quarter.

“We were very pleased with the company’s performance in the first quarter,” Idexx Chairman and CEO Jonathan Ayers said in a news release. “The benefits of our go-direct commercial strategy and innovation pipeline drove strong gains in our recurring revenues.”

In 2015, Idexx transitioned to a direct-sales-only model for its U.S. Companion Animal Group diagnostics division. Previously, it had sold the products indirectly through resellers.

Idexx produces diagnostic and information technology products and services for veterinary practices and for livestock and poultry operations and tests for the quality and safety of water and milk. It employs about 7,000 people worldwide, including more than 2,000 in Westbrook, and operates in more than 175 countries.