MEADVILLE, Pa. - The death of a patient, especially when young and when the cause of death probably is avoidable, frustrates Carol Holmgren.

But when one recovers, her emotions soar.

Holmgren is not a medical doctor or physical therapist, but an assistant wildlife rehabilitator at the Tamarack Wildlife Rehabilitation and Education Center near Saegertown, the leading treatment center for bald eagles in Pennsylvania, according to its own survey.

In 2008, six bald eagles were treated at Tamarack, exceeding its 2007 record of five, Holmgren said.

Three of the six eagles from 2008 were rehabilitated, but three didn't make it, she said.

"We were thrilled that three of these eagles were released to the wild, but two that died showed a toxic level of lead when tested by the Game Commission postmortem," Holmgren said. The third dead eagle was not tested, she said.

The rise in eagle admissions and concerns about lead toxicity caused Tamarack to survey the 21 Pennsylvania centers licensed to treat bald eagles, receiving responses from 18, Holmgren said.

"We were surprised to discover that half of all Pennsylvania eagles needing rehabilitation in 2008 were treated at Tamarack, and in 2007 almost half were treated at our center," Holmgren said.

But the study reflects Pennsylvania eagle demographics because of the concentration of eagles in northwestern Pennsylvania in Crawford, Erie, Mercer, Warren and Venango Counties, according to Holmgren. There are more than a dozen nesting pairs in Crawford County alone, according to the Pennsylvania Game Commission.

The 18 centers reported that 63 eagles had been taken to them from 1999 to 2008, with the number increasing in recent years.

From 1999 to 2003, only 11 were admitted for rehabilitation, compared with 52 from 2004 to 2008, reflecting Pennsylvania's growing eagle population, Holmgren said.

In 1980, Pennsylvania had only three nesting pairs, all in Crawford County, but now has at least 155 pairs, in 47 of its 67 counties, according to the Game Commission.

One of three reasons caused 31 of the 63 eagle admissions in Tamarack's survey, Holmgren said.

Vehicle impact was the primary cause for 14 eagles, shooting for 10, and confirmed lead poisoning for seven, she said. Other causes included electrocution, drowning, avian pox, West Nile virus, and leaving the nest too young.

Holmgren said she and Sue DeArment, who runs the Tamarack facility, believed lead might be a larger problem for eagles in Pennsylvania because those seven eagles were the only ones tested for lead poisoning.

Bald eagles ingest lead when they eat waterfowl that have swallowed lead sinkers or old lead shot from the bottom of ponds, upland game animals that have been shot and left, or portions of deer that hunters have discarded but that contain lead shot.

Research from Iowa, Minnesota, and Nebraska, where more lead testing has been done, indicates eagles admitted for trauma or starvation may have underlying lead poisoning, Holmgren said.

Additionally, because of its varied symptoms, lead poisoning can often be mistaken for avian flu, avian pox, starvation, ear mites, and even the crippling effects of being shot or wounded, she said.

"Without testing, we're not certain," Holmgren said. "We need to know how best to treat these birds."

Holmgren remembers a heartbreaking loss of one of Tamarack's juvenile bald eagles to lead poisoning in 2008.

"It was a beautiful young bird, chestnut brown in color, that didn't pull through," she said. "Sue and I did all we could for the bird. We were feeding it through a tube. It was a week before it died."

To improve treatment, Tamarack is working toward testing all its eagles for lead poisoning. But time and cost are problems.

"We can send out to a lab, but it's more than $100 per test, and it takes 10 days to two weeks to get results the bird is dead by then," Holmgren said.

Overnight shipping of a test speeds the process, but it still takes about 48 hours to get results, time that delays proper drug therapy, she said.

Tamarack would like to conduct its own lead testing on site.

Test results would be known in minutes, but it would cost about $2,000 - money the center can't spare because the poor economy has reduced donations, Holmgren said.