The Anxious Animal

Jacqui Neilson, DVM, DACVB


Anxiety/fear is an underlying component of many behavioral problems in companion animals.  Aggression, destruction, house-soiling and self-mutilation behaviors can all be triggered by anxiety/fear.  Therefore it is important to consider this powerful emotional state when working up a behavioral case. 

Fear is an adaptive behavior in many situations.  When faced with a novel stimulus, being wary and cautious may be beneficial to an animal.  However many pets develop maladaptive fears or anxieties or fear responses that are excessive in light of the actual threat.

There are sensitive periods in an animalsí life where they are more accepting and open to new experiences and things.  A lack of exposure to stimuli during these sensitive periods may result in a pet that has an abnormal fear response later in life. 

Animals that are fearful/anxious often respond to a trigger stimulus in one of four manners:  flight, fight, freeze or fiddle. While most people recognize a pet that is cowering, trembling and hypersalivating is fearful there are some more subtle signs of anxiety that may not be recognized by the casual observer.  Yawning is often seen in anxious animals as well as lip licking.  Some fearful animals show no evident avoidance or withdrawal behaviors but instead appear very offensively aggressive. These pets may have learned that the best defense is a good offense.  The chosen response may be based upon petís temperament, the particular situation, the trigger stimulus and reinforcement for past behaviors.  For example, the dog that is wary of nail trims due to a past negative experience may growl at the owner when they try to perform a nail trim. If the aggressive display is successful at stopping the nail trim the aggression was reinforced and is likely to occur again. 

Management of anxious or fearful animals is best accomplished by systematic desensitization and counterconditioning.  To begin a program, the trigger stimuli first need to be identified.  Then, if at all possible, these stimuli should be avoided unless they are part of a training session.  In some situations avoidance is impossible, such as avoiding thunderstorms for the thunderstorm phobic pet.  However, the best attempts are made to minimize the fearful stimuli if they cannot be completely avoided.  The owner should then work with the pet at achieving calm, obedient relaxed behavior when the trigger stimuli are not present.  This can be accomplished by giving obedience commands and rewarding the desired emotional and physical state (e.g. reward a relaxed sitting dog) when it is achieved.   When the pet is conditioned to be calm, relaxed and obedient without trigger stimuli present the stimuli can be added in a gradient fashion starting with a very low intensity.  The pet is rewarded for exhibiting calm, obedient behavior in presence of the low intensity stimulus.  The intensity of the stimulus is then systematically increased when the pet has demonstrated non-fearful behavior at the previous intensity until full level stimulus intensity is reached.  This is a slow process that may take months to complete.  Sometimes the addition of a head collar (Gentle Leader, Premier Pet Products) can help to calm fearful dogs and quicken the process.  If an undesirable response is achieved (the pet shows anxiety) then the owner should try to remove the pet from the situation and decrease the intensity of the stimuli at the next session.  Comforting should be avoided as it may inadvertently reinforce the fearful behavior.  Punishment should also be avoided as it may serve to increase anxiety regarding the trigger stimuli. 

For situations where the trigger stimuli canít be avoided or a calm starting point for desensitization cannot be achieved, drug therapy may be helpful in management of the anxiety.  Benzodiazepines (diazepam, alprazolam, etc.) have anxiolytic effects and are quick onset, taking effect 1-2 hours after administration.  Some animals have a paradoxical reaction to the benzodiazepine class of drugs and seem to get more agitated on the medication Ė treatment should be discontinued if this is noted. Also, the sedation sometimes seen with benzodiazepines is sometimes not desirable.  If the pet shows any evidence of aggression benzodiazepines should be avoided as they may cause disinhibition and a worsening of the aggression.   Serotonin enhancing medications are another treatment option for the anxious animal but these anxiolytic effects may take several weeks to be evident.   There is currently only one serotonin enhancing drug labeled for the treatment of anxiety, clomipramine (Clomicalm, Novartis Animal Health) that is labeled specifically for the treatment of separation anxiety.  If drug therapy is implemented, ideally it would be done for a short course (3-4 months) while behavioral modification is implemented. 

Elderly pets that suffer from geriatric onset anxiety may actually be suffering from cognitive dysfunction syndrome.  Historical questioning may reveal other signs in addition to the anxiety such as disorientation, change in sleep wake cycle, change in social interactions and loss of house-training. If cognitive dysfunction is suspected therapy should be targeted at that diagnosis. 

Anxious animals can improve but it takes time, effort and consistency on the part of the owners.