Animal welfare organizations warn, as household income falls and homes are repossessed, family pets are also increasingly falling victim to the global economic crisis.
"For about a month we've been getting more and more calls," said Constance Cluset, spokeswoman for the foundation set up by former screen siren Brigitte Bardot to look after vulnerable animals in France.
"People are telling us: 'I can't cope anymore, I've no more money'," she said, citing the case of a man in the Normandy region who lost his house last week and is now seeking shelter for his 16 dogs.
It is a similar story on the other side of the Atlantic in the United States, where last year's collapse in the sub-prime mortgage market triggered the worldwide slowdown.
Recent US press reports spoke of a woman made homeless in Texas and now living in her car with 22 dogs. Around two thirds of US homes have pets, according to the American Pet Product Manufacturers' Association.
"Anywhere people are losing their home it's going to be a crisis for pets," said Kate Atema-Natrass, a senior program officer at the International Fund for Animal Welfare, based in the state of Massachussets.
"The number of people who have lost their home looking for places to put their animals is increasing hugely. This kind of problem is not isolated to any one county or any one community," she added.
In Europe, France has the largest number of pets per head of population, with 65 million animals living alongside 63 million humans. Animal welfare groups are struggling to cope with the crisis.
"Before, most people who abandoned pets did so in the summer," said Nicole Jabin, head of an animal refuge in Combs-la-Ville, a Paris suburb, noting a French tendency to dump animals ahead of the summer holidays.
"Now, with all these 'For Sale' signs going up, it's an all year-round problem," she complained, adding that she suspected that "some bastards are exploiting the crisis as an excuse to get rid of their animals."
In Britain, London's celebrated Battersea Dogs Home announced at the end of last year that it had reached its capacity for homeless hounds for the first time in its 148-year history.
And in Barcelona, Spain, welfare workers have begun to convert office space into overflow kennels to accommodate strays.
According to the website of the American Society for the Prevention of Cruelty to Animals, between 500,000 and one million US cats and dogs are threatened by homelessness and the number of abandoned pets has doubled in four months.
"It started when people began to lose their homes. When people are beginning to be displaced it's a huge issue afterward, what to do with their animals," said Atema-Natrass. "We have certainly reached crisis level.
"Many people were forced to make a decision between their children and dogs and cats and, of course, they kept their children. Fewer homes are available and fewer people are interested in taking in more financial obligations.
"Across the developed world, charities are really trying to help. IFAW supports a group in Germany, which supports people who can't afford to feed their animals," she said.
In France, this role is taken by the Society for Animal Protection, but the financial burden is a heavy one.
According to the Brigitte Bardot Foundation, a chihuahua can cost 240 euros a year to feed and a Saint Bernard 960 euros, plus up to 300 euros in vet's bills. In the United States, it costs 800 to 1,200 dollars.