It began with neighbors complaining about odors coming from the unkempt Uniontown home last month. Humane officers donned biohazard suits and breathing masks before entering, and emerged with 14 cats, six ferrets, four rabbits, one boxer dog and one red-eared slider turtle.

But inside among the feces, garbage and debris were nine dead animals, including seven cats.

Similar scenarios of animal hoarders play out about a dozen times a year in Allegheny County. Authorities have varying opinions about not only how hoarding should be handled, but even how to define it.

A group called the Hoarding of Animals Research Consortium, affiliated with the Tufts University Cummings School of Veterinary Medicine in Grafton, Mass., has been studying the problem for 10 years. Its 2006 report estimates that as many as 250,000 animals per year are acquired by animal hoarders.

The consortium's report identifies four characteristics of animal hoarding:

• Failure to provide minimal standards of sanitation, space, nutrition and veterinary care.

• An inability to see that level of care is creating problems for animals and humans.

• Obsessive attempts to maintain and add to the numbers of animals even while conditions get progressively worse.

• Denying that living conditions are creating a problem for animals and people.

Dr. Gary Patronek, a veterinarian and adjunct professor at the Tufts veterinary school and director of Animal Welfare and Protection at the Animal Rescue League of Boston, said hoarders have cost his shelter an estimated $1 million over the past three to four years. The cost includes neutering and other veterinary care for the animals of hoarders, as well as the daily routine costs of caring for and boarding them.

Animal Friends, which operates a shelter in Ohio Township, sees about six cases of animal hoarding each year, said Kathy Hecker, one of the shelter's two humane agents who investigate and prosecute animal cruelty cases, which includes hoarders.

The shelter's veterinary cost for caring for a single healthy cat can range from $365 to $390, plus $10 daily for boarding. A single healthy dog can cost between $444 and $509. Some animals must be held for weeks, months or even years, depending on court cases. Costs are higher for injured or sick animals.

Western Pennsylvania Humane Society also has humane agents, as do several shelters in surrounding counties.

The society, which operates shelters on Pittsburgh's North Side and in Elizabeth Township, also sees about six hoarding cases per year, said humane agent Ron Smith. He said he couldn't put an actual dollar amount on what hoarders cost the society.

According to the Tufts research consortium, animal hoarders fall into three main categories: the overwhelmed caregiver, the rescuer and the exploiter.

The first begins providing adequate care but a change in circumstances -- such as job loss or health problems -- impacts care capabilities. The rescuer has an inability to say "no," leading to more and more animals coming under his care. And the exploiter may have mental problems, such as borderline personality disorder or schizophrenia.

While many hoarders do fit the stereotype of women over 60 years old who live alone and have very little income, the HARC report says there are no age, gender or socioeconomic boundaries.

"Many [hoarders] have had very fragmented childhoods with very little security," said Dr. Patronek, an editor of the consortium report. "They have a desire to acquire many animals. We are looking at addictive behavior."

Ms. Hecker has seen a wide array of hoarders, including a well-educated Sewickley woman with a highly paid, corporate job.

"When she died [several years ago], friends called the shelter because they were worried about her cats, who they said she loved so much," Ms. Hecker said. "We went in and there was wall-to-wall cat feces throughout the house. There were about a dozen cats and all had untreated medical issues."

She's also seen hoarders with more than 100 animals, including those who started out as "rescuers" who saved animals and found new homes for them.

In January 2002, Ms. Hecker went to the Swissvale home of Nancy Cross, after a furnace repairman complained about deplorable conditions inside the home. Ms. Hecker removed 63 dogs, three cats, and one turtle, and found bodies of 29 dogs buried in the back yard. Ms. Cross was convicted on multiple counts of animal cruelty charges, and ordered to pay $8,327 in fines.

Mr. Smith says many of the hoarders his shelter deals with are elderly women, "but we're seeing more younger people and couples as well. A few years back we went to the home of a retired school teacher and found 100 cats and what was probably 10 years accumulation of feces."

Though all types of animals are hoarded, Mr. Smith said it's usually cats "because they are small and can be hidden inside the house. When we get hoarders with dogs, they usually live out in the country where there are no neighbors to complain about barking."

In Pennsylvania, prosecuted hoarders are charged under Pennsylvania Consolidated Statutes, Title 18, Section 5511 cruelty to animals, which mandates that it is a summary offense for anyone who "wantonly or cruelly illtreats, overloads, beats ... or neglects any animal ... or deprives any animal of necessary sustenance, drink, shelter or veterinary care, or access to clean and sanitary shelter ..."

The penalty for a summary offense is a maximum fine of $750 and 90 days in jail.

Often, raids on hoarders are accompanied by the glare of TV cameras.

The Western Pennsylvania Humane Society prefers a quieter approach.

"Our initial effort is to gain their trust," Mr. Smith said. "We do not want to cause any more anxiety for them and we want to treat them with dignity. Many of them really do care about their animals and they want to say goodbye. Some of these people started out with one or two animals and it got ahead of them. Many in that situation actually thank us for helping them out."

Such was the case with a young couple, who told authorities they only had four or five cats. Mr. Smith, who entered with a warrant, said odors inside the house indicated otherwise.

"I heard noises above the ceiling, and found a trap door in a closet," he said. "I opened it and found 28 cats in the attic. They loved them and didn't want to give any of the cats up, but the health department had red tagged the house" and the cats were taken away to the shelter.