For veterinary practitioners with an interest in companion animal behavior, these are the best of times and worst of times.

First, the good news: Thanks to the increase in intra- and international transportation rescue animals, they’re the best of times because practitioners may encounter dogs and cats (to a lesser degree) displaying behaviors seldom seen in purebreds or animals of local origin from long-established companion lines.

These are the worst of times because these animals often arrive with little or no history. Additionally, any history they arrive with may be incomplete or unreliable.

Consider a transport dog I recently encountered in my behavior/bond practice. Jake was an approximately 2-year-old Australian shepherd (or mix) presented for aggression.

Specifically, Jake had bitten two members of the household, a 42-year-old male and a 17-year-old female. He also was showing signs of separation anxiety when his primary caregiver, a 62-year-old female, was out of his sight.

Jake arrived with no history prior to the time he became part of a national breed-rescue/foster organization.

During the approximately three-and-a-half months between when the rescue group picked the dog up at a southwestern shelter and the current family in New England adopted him, he stayed in four different foster homes in divergent geographic locations and was adopted and returned twice for displaying various forms of aggression. Several of these moves involved travel over long distances in private planes.

Considering that establishing and protecting the territory ranks as the No. 1 animal priority, that’s a lot of physical and mental territorial instability in an incredibly short span of time!

But that’s not all. Unlike many cases where whatever history came with the animal comprised all that would be forthcoming, Jake represents the best of times in that his last foster provided additional information when asked.

Let this serve as a reminder that, if you don’t get much in the way of a transport animal’s history, it never hurts to ask the foster or the rescue organization for more. Sometimes they don’t have any more because they didn’t bother to collect any. Those are the worst of times because, although we’re not necessarily doomed to repeat past mistakes without a history, lacking one does make resolving problem behaviors more difficult.

But sometimes, as in Jake’s case, you can get lucky. The additional history revealed that Jake’s original owner bought the dog from a breeder, then let him run loose when she wasn’t home. During that time, he would eat food a neighbor left out for her own dog.

This apparently angered the neighbor who caught and muzzled the dog and tied him to a pole. She then called animal control who took the dog to a shelter.

The additional history also revealed that, after the owner surrendered Jake to the shelter, he was moved to his first foster home, where he proceeded to jump a fence and take off. After being lost "for a few months," he was captured in approximately three-and-a-half months before he wound up in the system again. After some time in a kennel and where he was neutered, he experienced the rocky ride down the rescue road described above.

Few people would argue that Jake had been through the worst of times. But for those seeking to help these animals, any history can be valuable from a behavioral perspective when coupled with an evaluation of the animal.

Just knowing that Jake came from a breeder eliminated the unknowns associated with dogs from long-established, free-roaming roots, including the possibility of feral or wild breeding in the mix. That the neighbor muzzled the dog suggests Jake may have resisted capture for some reason.

However, we can’t rule out that a frustrated person did it to punish him for habitually eating the food she put out for her own dog. Jake’s more extensive history did make it clear that he probably spent much of the previous year, if not longer, without any stable and enduring human presence in his life.

My observations of the dog and his responses to his new owners, me, and the many novel features in our clinic setting led me to conclude that he had received enough quality canine or human parental care or a combination thereof early in his life to trigger the epigenetic changes compatible with survival in a more human- and possibly even companion-animal environment.

His responses during the evaluation, to routine events in his new home, and to owner-initiated changes to address his behavioral problems weren’t those of a dog with a deeply entrenched free-roaming scavenger or predator orientation. They were consistent with those of a dog from strong working dog roots with a reserved temperament whose experience with humans had been less than optimal.

In general, I tell my clients whose dogs have behavior problems that all dogs are from Missouri, the Show Me State, when it comes to making changes. They’re not going to give up behaviors that enable them to protect themselves and their territories — which often includes their owners — until those people prove they’re willing and able to assume these responsibilities themselves.

These dogs don’t do this to be difficult. They do it because ceding that responsibility to their owners means entrusting their lives to those people.

Some dogs require more proof than others. Those most stressed by their protective role who put more energy into their aggressive displays and display other symptoms of stress often will give it up sooner than those for whom the cost isn’t so high.

However, my experience with transport animals suggests that, contrary to any human beliefs that may want to position these animals as victims, most of these animals are survivors. They know they can make it on their own if they need to, simply because they already have.

Consequently, they’re not as likely to accept the "mostly consistent" human responses that some dogs lacking their background will. For Jake’s owners, who are tough survivors themselves, that’s not an issue because they believe he’s worth the effort.

However, sometimes transport animals are marketed with histories that position the animals as innocent victims who only need a loving forever home to vanquish all the effects of the animal’s past. Sadly, those lacking experience with normal and problem animal development may interpret this to mean that all these animals need is their heartfelt sympathy and lots of love.

Even in the best of worlds with transport dogs like Jake from strong companion dog roots, sympathy and love aren’t enough. It takes commitment, hard work, patience, self-control, and self-confidence as well as confidence in the animal to turn these dogs around.

If animals like Jake represent the best of times when it comes to transport ethology, the dog we’ll meet next month represents the worst.