Behavior Counseling: Diagnosing a Behavior Problem - Is It Medical or Behavioral?

What can cause a pet to behave inappropriately?

Behavior problems in pets can be due to medical issues, behavioral factors, or both. A clinical history, physical examination, and diagnostic testing will help determine if there are underlying medical conditions contributing to the problem.

It may be possible to identify a single cause for a behavior problem. However, behavior can be influenced by a mix of genetics, environment, learning and physical health.

For example, a pet scared of children may become more irritable when they are in pain. Common sources of pain include dental disease, arthritis, and infections. Joint pain or neurologic conditions also make it more difficult for your pet to move away from a child and can contribute to an aggressive response if your pet feels ‘stuck’ or cornered. Hyperthyroidism in cats can contribute to aggressive behavior, or even urinary marking when left untreated. Sometimes a behavior problem can resolve completely once the underlying disease is treated, though often there is also a need for some specific behavioral therapy.

What are some causes of problematic behavior in medically healthy pets?

Changes in the environment or the daily routine may contribute to the emergence of behavior problems. For example, moving to a new home, or adding or losing a household member can have a dramatic impact on a pet’s behavior. Many pets are sensitive to the health or emotional stress level of the people and pets they live with. Medical and/or cognitive changes associated with aging may cause a pet to be even more sensitive to environmental changes.

Sometimes, undesirable behaviors occur simply because they are natural behaviors for a species. For example, it is natural and normal for a dog to dig in the yard, or a cat to scratch a vertical surface. These behaviors are self-rewarding, becoming part of your pet’s routine as they continue to engage unless you intervene. If you notice a behavior that you find unappealing, it is best to seek behavioral advice immediately. Remember, the behavior will naturally strengthen over time. Interventions used to reduce normal but undesirable behaviors should always include finding a substitute for the behavior and then teaching your pet to engage in the substitute behavior (see handout “Dog Behavior – What is Normal?”).

"If you notice a behavior that you find unappealing, it is best to seek behavioral advice immediately."

Some primary behavioral illnesses include frustration intolerance, impulsivity, extreme anxiety, and phobias. These conditions may develop due to past experiences, like exposure to inappropriate training techniques or an inability to escape frightening situations. Additionally, certain breeds have increased risk of developing specific medical conditions, there may be a genetic predisposition to developing behavioral illnesses.

What role do genetics and early experience have in the development of behavior problems?

A pet’s behavior is influenced by their genes and their environment. Two pets raised in the same environment will mature into adults with different behavior patterns or personalities. Genes affect the way an individual processes environmental stimulus. These genetic influences cannot be changed.

Very early environmental influences, including exposures that occur before an animal is born, can influence future behavior. For example, the health, diet, and stress level of the pet’s mother can impact brain development and future behavior, not only while the pet is being nursed as an infant, but also while an animal is still in the uterus. Puppies and kittens learn about social communication when they interact with their littermates. Orphan animals may exhibit inappropriate social behaviors such as excessive mouthing or not knowing when to stop biting.

"A pet’s behavior is influenced by their genes and their environment."

Even after puppies and kittens are adopted into their new homes, the effect of their early experience continues to be important. Between 3 to 12 weeks for puppies, and 2 to 7 weeks for kittens, are their most sensitive period for socialization. Experiencing healthy social and environmental stimuli during this period can have a strong positive impact on their future behavioral development. Excessive or traumatic exposures during this period may contribute to the development of behavioral problems such as fear of unfamiliar people.  

Is there any test that can be done to determine the cause of my pet’s behavioral problem?

To determine the reason for any behavior, a careful examination of the detailed behavioral history you provide will be conducted. It is important to create a timeline when you first noticed any behavioral changes or concerns. The timeline should include any changes in your pet’s health as well as changes in the physical and social environment. Provide a list of all medications your pet received since the onset of the behavioral concerns. Details can be important, including the nature of your daily interactions with your pet and prior behavioral interventions or training.

"Try to recall the details of specific incidents to help your behaviorist understand the nature of your concern. "

Try to recall the details of specific incidents to help your behaviorist understand the nature of your concern. Sometimes a video demonstrating the behavior can be helpful, but always ensure the safety and well-being of everyone, including your pet. Never put a person or pet in danger, or cause any stress to create a video.

A tentative diagnosis may be made based on the information you provide. A final diagnosis of a behavioral cause can only be made after potential medical causes have been ruled out.

What medical conditions can cause or contribute to behavior problems?

Health changes affect behavior. The following are some examples of changes in health that can affect behavior:

  • a decline in your pet’s hearing, sight, or other senses
  • organ dysfunction (e.g., liver or kidney disease)
  • hormonal diseases
  • diseases affecting the nervous system
  • diseases of the urinary tract (infections, tumors, or stones)
  • diseases or conditions that might lead to pain or discomfort
  • problems that affect the pet’s mobility

Any condition that leads to an increase in pain or discomfort can lead to increased irritability, increased anxiety, or fear of being handled or approached, and ultimately to increased aggressiveness.

Aggressive displays are usually successful at removing the immediate ‘threat’, so the behavior is reinforced and will continue. Medical conditions that affect the ears, anal sacs, teeth, gums, bones, joints, or back (discs) are some of the more common causes of pain and discomfort. If the pet’s mobility is affected, they may become increasingly aggressive, choosing to threaten and/or bite, rather than retreat. A decrease in mobility could also affect urination and defecation by reducing your pet’s ability to utilize its elimination area. Cats in particular may no longer be able to posture comfortably in their litter boxes.

Pets with diminished sight or hearing may have a decreased ability to detect or identify external stimuli. They might begin to respond differently to visual and auditory stimuli. Your pet may startle and snap (or swat) if they do not hear a person or pet approaching. There may be a reduced responsiveness to verbal cues. Sensory decline is more likely to be seen as pets age.

Diseases of the internal organs, such as the kidneys or liver, can cause a number of behavioral changes, primarily due to the toxic metabolites that accumulate in the bloodstream. Organ decline and dysfunction is more common in older pets. Medical conditions that cause an increased frequency of urination or decreased urine control (kidney disease, a bladder infection, bladder stones, or neurological damage), might lead to an increase in house soiling. Similarly, conditions that affect the frequency of bowel movements or bowel control, such as colitis or constipation, might lead to house soiling.

Diseases of the nervous system (brain and spinal cord) can lead to a number of behavior and personality changes. Conditions such as epilepsy, brain tumors, infections, immune and degenerative diseases can all directly affect a dog or cat’s nervous system and therefore its behavior. In the older pet, aging changes can have a direct effect on the brain, leading to cognitive dysfunction and senility.

The endocrine (hormone) system also plays a critical role in behavior. Overactivity or underactivity of any of the endocrine organs can lead to a number of behavior problems. Behavior can be affected by changes in the hormone production of the thyroid and parathyroid glands (in the neck), the pituitary gland (in the brain), the adrenal gland (by the kidneys), the pancreas, and the reproductive organs. Endocrine disorders are more likely to arise as your pet ages.

The aging process is associated with progressive and irreversible changes of the body systems. An elderly pet may experience varying degrees of organ disease and dysfunction. Cognitive decline and senility have also been recognized in older dogs and cats (see handouts “Behavior Counseling - Senior Pet Behavior Problems” and “Behavior Counseling - Senior Pet Cognitive Dysfunction”).

What tests need to be done to determine if my pet’s behavior problem is due to a medical condition?

It is important to check your pet’s physical health if their behavior changes suddenly without identifiable changes to their physical or social environment. Behavior changes usually develop gradually, whereas medical conditions can cause sudden changes in behavior. To check for medical conditions, your veterinarian may explore the following:

  1. Clinical history,  physical examination, and laboratory screening. An assessment begins with a clinical history and physical examination. The history you provide may be the only way to determine if there are behavioral or medical changes. Be certain to mention any changes or problems that you have noticed in your pet’s behavior, no matter how minor. Based on the signs you report, and examination and laboratory findings  a more comprehensive examination such as a neurological examination or sensory testing may be required. For some of these tests, your pet may need to be referred to a specialist.
  2. Dietary or pharmacologic testing. For pets that are licking or scratching themselves excessively, a diet trial or a drug trial may be used to differentiate a medical condition from a behavioral cause. Medications that relieve pruritis may also be prescribed. If your veterinarian suspects your pet’s behavior could be related to a seizure, a trial on an anti-seizure medication may be done.

It is always important to identify and treat underlying medical conditions once they have been identified. In many cases,  medical and behavioral conditions can be treated simultaneously.