A member of the Cape Breton SPCA tends to one of 33 dogs that were seized from an apartment in Sydney, N.S., in September 2009. The dogs' former owners were not charged, but they have been prohibited from owning animals. (CBC)

There are cases across the country of people taking dozens, hundreds, even thousands, of animals into their homes. These pet owners may not just be overly enthusiastic animal lovers — some researchers say they have a condition called animal hoarding.

Much of the research on animal hoarding has been prepared and compiled by a U.S. group called The Hoarding of Animals Research Consortium. The group draws on specialists with backgrounds in psychology, sociology, social work, veterinary medicine and animal cruelty prevention.

Information from their website and published documents has been used in compiling this FAQ.

What is animal hoarding?

There's a difference between hoarding animals and having a lot of pets. Animal hoarders have far more animals than is considered normal, and are unable to provide even minimal standards of nutrition, shelter and veterinary care for them. Often their animals starve, get sick and even die. The hoarders are in denial about their inability to care for their animals.

Who hoards animals?

Studies show that animal hoarders are typically older women who live alone and have little disposable income. Still, there are cases that defy the norm, with hoarders who are male or young or wealthy. There are even instances of medical professionals and veterinarians who hoard. Hoarders can appear relatively healthy and normal when they are away from their animals.

Why do people hoard animals?

There are many theories about why people hoard.

Some studies say hoarders think they are parents to their animals: They love them intensely, like a surrogate child. Other hoarders believe they are the only ones capable of caring for their animals. Some think an animal will be euthanized if they don't care for it, while others believe they have special abilities to communicate and empathize with animals.

Usually animals played a significant role in a hoarder's childhood, which was often marked by chaotic or unstable parenting.

Some researchers believe animal hoarding could be a warning sign for the early stages of dementia. Others say hoarding can be considered an addiction: Hoarders deny their problem, feel isolated, and are preoccupied, just as an addict is.

Hoarders also share traits with those who suffer from obsessive- compulsive disorder, as well as those who have impulse-control problems, such as compulsive shoppers and gamblers.

What kind of animals do people hoard?

There are cases of hoarding involving almost any kind of animal imaginable. People have hoarded dogs, rabbits, ferrets, birds, guinea pigs and farm animals such as goats, chickens and cattle.

Because they are easy to obtain and conceal, cats are the most common. Sometimes people hoard more than one kind of animal, but usually they stick to a favourite species.

Some animal hoarders also amass inanimate objects.

How many animals have people hoarded?

There are cases of people hoarding over 1,000 dogs or cats. With smaller animals, like rats or mice, people can easily hoard hundreds at a time.

Is it safe to live with all those animals?

There are many diseases that can be passed from animals to people, like ringworms, rabies or cat-scratch fever. A person with a compromised immune system — due to HIV, cancer, diabetes and other conditions — is especially at risk.

A hoarder's home can be highly unsanitary. When a case of animal hoarding is discovered, public health officials will sometimes condemn the home, declaring it unfit to live in. The air quality can be so low that health officials will wear masks when they enter the home. They have found homes covered with animal urine and feces. Some of the homes don't have working heat, electricity and proper plumbing.