WESTBROOK – Idexx Laboratories, which hopes to boost sales to $1 billion next year with the introduction of a new diagnostic tool for veterinarians, plans to add another 500 jobs at its Westbrook headquarters by the 2011, the company’s CEO said.

The biotechnology company’s next-generation blood chemistry testing machine for veterinarians is expected to contribute to steep revenue growth for Idexx and to the creation of hundreds of jobs, said Jonathan Ayers, the company’s chairman and chief executive.

The company is benefiting from an increased willingness of pet owners to spend money to keep their dogs and cats alive and healthy.

“We’re in a growth industry, and we’re in a high-growth segment,” Ayers said.

It’s uncommon these days for manufacturing and high growth to be mentioned in the same sentence, particularly in Maine.

But Idexx has carved out a niche as a leader in diagnostic research and development for products and equipment for veterinarians. Tests include heartworm, Lyme disease and parasites. More than 80 percent of its revenue comes from that segment.

The company has more than 4,000 employees at 60 facilities in 14 countries; 1,421 of them are at its Westbrook headquarters.

It has been adding 100 or so employees a year in Maine in recent years and will add 500 more by 2011, part of a pending $75 million expansion in Westbrook. In the interim, the company has leased space at four sites in Westbrook and Scarborough.

The latest tabletop machine that’s under development will replace current units by making it easier and faster for veterinarians to do blood testing in their offices.

The technology represents the next generation in analyzing blood chemistry, and 200 scientists and workers are developing the product, Ayers said.

Idexx has other lines of business, including water testing and products for production animals, such as horses and cows. But testing products for companion animals tend to be the company’s bread and butter, said Steve Hirshon, a broker for Maine Securities in Portland.

“At the end of the day, people will pay almost anything to support their pets,” Hirshon said, “and Idexx has benefited from it.”