It is my personal belief that Madonna, ever conscious of her public image, decided to tote about pet dogs in order to be photographed with them, since Mansfield did the same.

It is a well known fact that Jayne was killed in a car accident close to New Orleans, along with one of her pet dogs; from snopes.com:

Dead at the scene were the driver, Ronnie Harrison; actress Jayne Mansfield; Mansfield's boyfriend Sam Brody; and Mansfield's small dog.

From The Bark Unleashed:

I read in a biography of Marilyn Monroe–wannabe Jayne Mansfield that she lived in a house decorated all in pink—pink bathroom fixtures, pink wallpaper, pink couches.

[Mansfield] . . . also had several large pink Poodles, which she never toilet trained. She felt that training dogs was an intrusion on their freedom.

As a result, visitors to her mansion noted that there were clusters of dried dog doo embedded throughout her fuzzy pink carpet.

POSING WITH DOGS

I'm not sure why, but photographers from the 1920s on through to the 1960s thought it was suave, stylish, or funny to snap celebrities with their dogs.

Madonna, no dummy to past trends and wanting to capitalize off them (she's incapable of being original, remember), has been seen quite a bit with four-legged companions.

1920s Actresses Posing With Critters

First, a few examples from the earlier show business days:

I know, I know, this is unfair -- you're going to have a hard time telling which is Madonna and which is the dog. But seriously, folks, seriously...

Below: Madonna with pet bull Pepito, chihuahua Chiquita, and other pets.

Notice that none of these poor animals appear to be happy to be with her. I didn't believe in pet psycho therapy until now.

Below: Marilyn Monroe, born: 1926 died: 1962.

Far left: posing with "Maf," a gift from Frank Sinatra. Right: posing with Hugo the Basset Hound. Marilyn posed for a photo series with a chihuahua, but I am including only 2 or 3 shots from that series.