A new survey has revealed that millionaires are far more dog-friendly than the rest of population.

According to a study by Spectrem Group, 58% of millionaire pet owners have a dog while only 37% own a cat. Only 3% keep fish, 2% birds and 2% have a horse.

The survey carried out in America revealed that 39% of the rest of US households owned a dog, compared to 33% of households that owned a cat.

So why have millionaires gone to the dogs?

Jennifer Cona, a trust and estates attorney and partner with Genser Subow Genser & Cona in New York, does a lot of work on pet trusts.

She said dogs provide one thing especially important to the wealthy – unconditional love.

"You don't get that from a cat," she said. "Dogs are like children for some families, except they don't mess up in college or run off with money.Sometimes it's easy to see why dogs are the favourite child."

Plus, she added, millionaires know that dogs don't love them for their money.

Millionaires show their love for their dogs in part by their spending. One quarter of millionaire pet owners spend more than $1,000 a year on their pets every year, the Spectrem study said, while more than half spend more than $500 a year.