BOSTON -- The federal government is reviewing 44,000 complaints that were filed last year concerning potentially dangerous – and sometimes deadly – flea and tick products for pets, Team 5 Investigates reported Sunday.

Michael Scott's 8-year-old shih tzu Ben had a severe reaction after an application of Sentrypro XFC Flea and Tick Squeeze-on.

"His eyes were glassy and his look was like what did you do to me?" Scott said. "Within an hour he started to twitch, then he was biting himself. As soon as he lay down, it was like a jolt. It was like someone prodding him with electricity."

Sentrypro XFC contains the pesticide cyphenothrin, which is approved for use as an over-the-counter flea and tick medication. However, cyphenothrin is one of 10 pesticides now suspected in the thousands of cases reported to the Environmental Protection Agency in which pets got seriously sick or died after its use.

The agency "is intensifying its evaluation of spot-on pesticide products for flea and tick control due to recent increases in the number of reported adverse reactions in pets treated with these products," it said in a statement posted on its Web site.

"Adverse reactions reported range from mild effects such as skin irritation to more serious effects such as seizures and, in some cases, death of the pet," the statement said.

Sentry Pro's manufacturer Sergeant's Pet Care Products told Team 5 Investigates it "welcomes the increased evaluation of spot-on pesticides. The health and safety of pets is Sergeant's number one priority. This is an industry-wide issue."

Its products represent 11 out of approximately 70 under EPA scrutiny.

"It seems to me when you have hundreds and hundreds of complaints and with documentation from vets and so forth, something is wrong," said Scott.

The EPA has not initiated a product recall, nor does it suggest the products not be used. However, the agency does advise pet owners to use the products with caution and monitor pet behavior carefully after their use.