Many people new to sharing their homes with dogs or cats will turn to their new pet's veterinarian for information about how to keep their animals healthy.

In response, practitioners often supply information about and schedules for vaccines, fecals, heartworm and other preventive testing, flea and tick control, appropriate time for spay or neuter, and other concerns related to animal physical health. Any mention of preventive behavioral health may be limited to recommending some sort of training classes for puppies or unruly dogs.

One valuable addition to this lineup — free-access crate-training (FACT) occurred to me early in my veterinary medical career when I made the acquaintance of a woman who local lore claimed had a magical way with cats. Given that she lived in a small mobile home with 17 strictly indoor cats with nary a problem, her claim seemed legitimate.

Unfortunately, I met her shortly after she introduced the 18th cat into her household and unwittingly triggered feline meltdown. Multiple cats started marking with urine and claws.

But because she had so many cats, she had no idea which cats were doing what, let alone when. Worse, the problem behaviors persisted even though she removed the newcomer within a matter of days.

I knew that animals of the same species living in the same limited area divided it into communal and personal spaces, but until that day I didn't recognize the different ways this could play out in companion animal households. A quick refresher: Communal areas carry a neutral charge relative to other animals in the same fixed space, whereas personal spaces carry more emotional ones.

When all goes well, animals of the same species living together typically perceive spaces where feeding, playing and elimination occur as neutral, and spaces where individual animals sleep as personal. In both wild and domestic animals, whether animals tolerate members of the same or other species in their personal space is a function of multiple factors.

Much variation also exists regarding the spatial needs of those belonging to the same species. This variability may occur within any species, but often are more noticeable among cats.

The entwined trio of feline behaviors — solitary, nocturnal, territorial — helped ensure the cat's predatory success and survival in diverse natural environments for thousands of years. However, that same trio may create problems for cats living in human households with limited space.

The essence of these problems boils down to the answer to one question: How much space does a cat need?

Unfortunately, the answer to that is: It depends on the cat. The average multicat household isn't like controlled laboratory or farm settings where animal populations tend to be uniform. In such environments, it's possible to determine how much personal space each animal needs to ensure the animal's welfare.

However, my client never intended to share her small mobile home with 17 cats. She chose to get the first two. But as she explained, "The rest of them just sort of happened."

She did recognize that each cat claimed their own personal space, and that some cats were less tolerant than others if any cat or just a specific cat or cats violated that space. However, she didn't notice how some cats required more personal space than others.

Like many multiple-pet owners, the Mobile Home Cat Lady focused on her cats strictly as individuals and prided herself in her ability to do this. But because of this, she missed the bigger picture.

Each additional cat triggered two space-related changes. As the amount of personal space increased, the amount of shared spaced available to the feline group decreased.

She did notice that it took longer for successive cats to fit in and the group to settle down as the number of cats increased. This occurred because each new cat brought her home closer to its feline carrying capacity. The 17th cat took the group to its tipping point, and the addition of the 18th triggered a territorial meltdown.

What's amazing is that it took so many cats to trigger this effect. The mobile home wasn't that large, and it wouldn't be at all unusual for some previously free-roaming solitary, territorial and predatory cat to claim the whole space. Nor are behavioral problems that occur in response to fewer cats living in larger spaces that uncommon.

Because of this, I started recommending preventive FACT for kittens and cats as well as puppies and dogs for spatial reasons. When done properly, this creates a portable private space for the animal. This also yields other benefits for these animals and their owners, including a valuable way to prevent urine- and stool-marking or addressing elimination problems when they occur.

In my experience, animals who perceive their crates as private spaces also make the transition to new homes more easily. When a piece of "home" goes wherever the animal goes, this enables the animal to explore and scent-mark the new space while maintaining a secure home base within the alien space.

Compare this to the cat lacking such a secure space who can't feel secure in her new home until she lays down scent trails and marks key verticals to chart a safe path through the new space even in limited light. Until she does this, she reverts to nocturnal behavior and may drink and eat only minimal amounts. If her owners take weeks to unpack and constantly add or rearrange objects during this period, the increased territorial stress the animal experiences may precipitate new or exacerbate existing medical problems.

Additionally, FACT serves as a valuable adjunct in an era where no one can say with certainty that they and their loved ones — including their animals — won't need to evacuate their homes due to natural or other disasters. Animals who perceive their crates as havens can prevent a major source of owner-stress at such times, i.e., the animal who resists crating or goes berserk when confined.

When FACT is built into the animal's lifestyle, it also makes it easier for owners to keep documents and other pet-related paraphernalia together in one place where they easily can grab and move it along with their crated animals.

During evacuations, properly crate-trained, well-behaved animals also are more likely to be accepted in motels and hotels or even the homes of private citizens than animals who are not. Even if animals can't stay with their owners and must go to an animal shelter of some sort, crate-training provides benefits. In addition to having the comfort of a space the animals perceive as havens, crates also provide housing for animals in a setting where cages may be in short supply.

And finally, it goes without saying that placing frightened animals in their crates in larger cages can make life easier for some hospitalized animals and their caregivers.

So when clients ask for preventive tips to ensure the well-being of their new pets, consider adding FACT to your recommendations this year.