What’s cleaner than the soles of your shoes? A recent study suggests that the answer is your dog’s paws.

Researchers at Utrecht University in the Netherlands took samples from the paws of 50 assistance dogs and the shoe soles of their handlers. They did the same for an equal number of pet dogs and their people, in each case examining the samples for poop bacteria (Enterobacteriaceae), which are common outdoors, and for an important diarrheal bacteria (Clostridium difficile).

“The dogs’ paws turned out to be cleaner than the soles of the shoes,” says master’s student Jasmijn Vos. They concluded that paw hygiene was no reason to ban assistance dogs from hospitals.

There’s more – including a guide to giving pet medications – in Pet Connection, the weekly nationally syndicated pet feature I co-write with Kim Campbell Thornton and my daughter, trainer Mikkel Becker.

Your indoor cat spots a cat outside a window, and suddenly turns on a housemate cat or human. What’s going on? Here’s what I told a reader.

Q: Why does my cat attack me when he sees a cat outdoors?

A: If you’ve ever had a bad day at the office and then come home and snapped at your significant other, you have some idea of how your cat feels when he or she sees an unknown cat trespassing in your yard.

Cats get frustrated when they see an invading feline in their territory, and they may take it out on you or another pet or person, a behavior known as redirected aggression. It can be downright scary if you’re on the receiving end when your cat lashes out. It can be frustrating for you in other ways as well. Some cats accompany redirected aggression with urine spraying in an attempt to let that other cat know he or she is trespassing.

Free-roaming cats work out boundary disputes through scent (urine spraying), sight (claw marks on trees) and sometimes outright violence. Cats who live indoors don’t have opportunities to mark or defend their territory from cats passing through.

You don’t have to let your cat outdoors, though, to help him protect his patch of earth. A motion-detection sprinkler may send stray cats scurrying when they cross onto your cat’s property. And if there’s a particular window that offers your cat the perfect vantage point for spotting feline marauders, try putting up a barrier, whether that’s blinds you can close or a screen you can place in front of the window. You can even go so far as to close the door to that room and provide your cat with a perch near another window or door where he won’t see other cats go by.

Products such as Feliway that mimic calming feline pheromones may also help to prevent your cat from venting his frustration on your skin.

There’s more – including tips on helping pets adjust to a move – in Pet Connection, the weekly nationally syndicated pet feature I co-write with Kim Campbell Thornton and my daughter, trainer Mikkel Becker.

A reader had a simple question: Out of all the hundreds and hundreds of dog breeds on the planet, which is the largest and which is the smallest? Here’s my response.

Q: What are the largest and smallest dog breeds?

A: While humans measure height to the top of our heads, a dog’s height is measured at the highest point of the shoulder, called the withers. Most recently, the tallest dog was Freddy, a Great Dane, who stood 40.75 inches on all fours. Freddy (who also held the title of oldest Great Dane when he was 8 years old) died in January when he was 8.5, and no other dog holds the tallest-dog title yet. Great Danes aside, Irish wolfhounds are generally considered to be the tallest dog breed.

The most recent holder of the Guinness World Record for smallest dog was Milly, a Chihuahua, who died last year when she was 9 years old. She was only 3.8 inches tall.

What about weight? Guinness no longer awards titles for heaviest dog, since putting on the pounds can be detrimental to their health, but generally the heaviest breed of dog is the mastiff. Zorba, a male mastiff born in 1981, reached an astounding 343 pounds. He also held the title of world’s longest dog, at 8 feet, 3 inches. Zorba died in 1989.

Freddy, Milly and Zorba’s ages at death bring up an important point. Dogs who are extreme in any way, such as height or weight, or the flat faces of brachycephalic breeds such as bulldogs, don’t tend to live long lives. Dogs of more moderate size and conformation typically live anywhere from 10 to 20 years.

It doesn’t seem fair that dogs of unusual size or shape should live shorter lives because they’ve been either super-sized or downsized. Nature seems to have limits on how far we can push the design of dogs, and we go beyond those lines at peril to our pets.

There’s more – including expert tips on preventing separation anxiety – in Pet Connection, the weekly nationally syndicated pet feature I co-write with Kim Campbell Thornton and my daughter, trainer Mikkel Becker.