Just as clients may think medical problems occur out of the blue, some may perceive behavioral ones materializing that same way. Among these are animal behaviors that keep people up at night.

Sometimes seasonal changes may trigger these, but other times it initially truly may appear that nothing triggered behavior. Further complicating these cases, sleep-deprived humans quickly can become involved in downward emotional spirals with their animals compared to their more rested cohorts dealing with comparable problem behaviors that occur during the day.

Let's consider a case that in many ways represents the epitome of a nocturnal animal behavior and bond problem. The patient is a geriatric pug, Percy, who suddenly began vocalizing in the middle of the night.

Because of the dog's age, the immediate assumption was that he was suffering from canine cognitive dysfunction. However, physical and neurological examinations didn't support this diagnosis.

During the day, Percy's behavior was within the normal range for an animal with his physical limitations. He ate, slept and played with his toys normally. Although he'd lost vision in one eye when a larger dog attacked him several years previously, this didn't affect his ability to move through the owners' home.

At first, the behavior didn't occur every night. What couldn't be pinned down is whether this occurred because the owner slept through it some nights or because Percy didn't display it. Because the behavior already had been going on for several months when we discussed this, she couldn't answer that definitively. From her sleep-deprived perspective (to which her high-stress job also contributed), it seemed like forever since she had slept at all.

Further complicating matters, the client's negative responses to her previously beloved canine companion when awakened began changing his behavior toward her. In such situations, people often become caught up a cycle in which they first become angry and frustrated with the animal for disturbing their sleep. Then, they feel guilty and become over-reactive in what they consider an all-positive way to atone for their negative feelings.

However, the tone of voice and body language that accompanies the latter human reactions may communicate human neediness instead. This, in turn, can throw an already vulnerable dog like Percy into a human-protective position, which increases the animal's stress and reinforces the problem behavior.

Similar human-canine interactions are related to a range of animal behaviors owners perceive as negative. However, those that occur at night tend to result in more exaggerated emotional human responses.

In addition to the crying, Percy also periodically scratched at the walls. There also were times during the day when he would lie down in front of a first-floor cupboard and stare at it "for no reason at all."

Sometimes people get so fixated on the animal's problem that they ignore the context in which it occurs. Because context determines the meaning of any behavior, I asked the client to think about any changes that occurred in the environment before the pug's strange behavior began.

The owner then recalled that about 4-6 weeks previously, the first floor of their lakeside home had been flooded during a severe storm. This necessitated a move to the upstairs until all the damage could be repaired. Repairs included tearing up and replacing damaged floors and some walls, and thoroughly cleaning and painting all walls and woodwork.

The problem behavior began after they resumed living in the whole house.

For a geriatric canine blind in one eye with lenticular sclerosis in the other, the perceptual fallout of such events could be highly significant. Although most people recognize that dogs don't perceive their surroundings the same way they do, when problems arise they automatically may assume dogs do.

Consequently, it's easy for people to discount the role scent may play in the ability of older animals with dichromatic motion-sensitive rather than detail-oriented vision compromised with age-related vision-limiting ocular changes to negotiate their homes in limited light or darkness.

For example, one couple rushed their dog to the animal hospital, convinced the animal had experienced some horrible traumatic incident while kenneled that blinded her. However, examination revealed the dog had been visually impaired for quite a while. Most likely, this change had occurred so gradually and the dog compensated for it so well using scent and other perceptual cues that the owners never noticed.

What changed wasn't something that happened at the kennel. It was something that changed in the owners' home while she was kenneled. During that time, the owners did a major home renovation that included painting, adding new furnishings, rearranging old and otherwise destroying all the scent cues the dog used to move effortlessly in their home. Lacking these, she ran into objects and became so disoriented she refused to move at all.

Some dogs (and cats) following airborne scents at night may become so dependent on these for safe passage that they wind up behind partially open doors and won't back up. Other animals will hug walls until they wind up in a corner, then stop. When movement in the desired direction is thwarted, some of these animals, like Percy, will produce cries that owners describe as loud and eerie enough to cause them to leap from their beds and seek out their pets.

But what about Percy's staring at the closet and scratching at certain walls? This is where my living in a 1700s-era house with part of the basement at one with the earth comes in handy.

"By any chance do you have rodents in your home?" I asked the client.

"Funny you should mention that," she replied.

She went on to describe how she found mouse droppings in the back of a closest where they'd stored boxes of belongings after the flood. She set traps and thought that had solved the problem. However, recently she'd begun noticing droppings again.

She never thought rodents would be a problem because the house was relatively new. However, when major climatic events rearrange the landscape like the severe flooding did, opportunistic wildlife may enter via open doors or windows, or when damaged sheetrock is removed and not replaced until the supportive framework beneath it dries or is replaced.

Nocturnal behavioral problems are challenging because they involve multiple issues that may vary depending on the cause(s) of the behavior. However, regardless of the specific cause, most of these cases share one trait in common: client sleep deprivation.

Unless ways to address this are included in any treatment protocol, making even the smallest change to help the animal may overwhelm these people.