Clinical management of stereotypies in dogs

One does not treat a stereotypy but a dog suffering from a stereotypy. As, per definition, a dog doing a stereotypy is not sensitive to environmental stimuli, behavioral therapies are not treatments of choice. One has to use psychopharmaceutical drugs to modify the stereotypic behavior.

Stereotypy is only a symptom in a clinical syndrome. Other symptoms will prevail for the choice of the treatment. In overactivity disorders, selegiline will be effective, sometimes in combination with carbamazepine. In dissociative disorders, risperidone will be the drug of choice. In association with hallucinosis, sometimes a serotonine re-uptake inhibitor like fluvoxamine will be effective.

Stereotypies are symptoms in numerous complex behavioral pathologies. Their definition is varying with nearly each author. The neurophysiology and neuropathology leading to stereotypies and stereotyped movements have not yet been really defined. Multiple hypotheses have been proposed. The treatment is actually simplified with the use of dopamine and/or serotonine regulators.

In the scientific literature, one may find different definitions for the word "stereotypy".

Luescher is using the descriptive definition from Odberg (1978) and defines stereotypies "as behaviors that are repetitive, performed in constant form, and serve no obvious purpose". He also writes that "stereotypic behavior of companion animals includes licking or chewing specific parts of the body, hallucinatory behavior such as fly-snapping, whirling, pacing, freezing, rhythmic barking, wool-sucking, and self-mutilation."

Pageat (1995) defines a stereotypy as a regular repetition of a small number of identical acts, or group of acts, without spontaneous stop, and without any regulation. He proposes that several stereotypies are evolving from displacement activities, losing their regulation and becoming stereotyped with time.

Overall (1997) defines a stereotypy as "a repetitious, relatively unvaried sequence of movements that have no obvious purpose or function, but that are usually derived from contextually normal maintenance behaviors (e.g., grooming, eating, walking) [Luescher et al., 1991; Mason, 1991]. She differentiates stereotypies and obsessive-compulsive behaviors, saying that OCD includes stereotypies, self-directed behaviors, and so forth. She also differentiates between ritualistic and stereotypic behaviors and displacement, redirected and vacuum activities (Overall 1997, 1998). "By definition, some epileptic or seizure-like activity is stereotypic, which is one reason why the explicit and specific diagnosis category of OCD is preferable to that of stereotypy" (Overall 1998).

Shuster and Dodman (1998) define stereotypies and compulsive behaviors as "virtually synonymous"; they are "mindless, repetitive actions", derived from "species-typical naturalistic survival-oriented behaviors" (like predation, ingestion, locomotion and procreative activities). Several of these actions may lead to "self-injurious behavior" (SIB). "Compulsive behaviors stem from innate behaviors that have become displaced and autonomous, persisting as fixed motor sequences".

These definitions may seem confusing, sometimes even paradoxical. A stereotypy may describe a sequence of act, a symptom, even a disorder.

We have to try to have the strictest useful definition. We may have to differentiate between a stereotypy and a stereotyped movement. In ethology, fixed action patterns and ritualized behaviors may be stereotyped, because they are repetitive, and performed in constant form. But they have a purpose and are functional. So I will define the criteria of a stereotypy as following:

• A (group of) stereotyped movement(s),
• having no obvious function,
• having no spontaneous stop,
• seeming to be without any internal regulation.
• interfering with normal behavioral function.

Stereotypies are not including tics that are sudden, rapid, recurrent, nonrhythmic, single muscular movements such as face twitching, tongue dragging, lips licking, etc. or vocalization.

In this definition, a stereotypy is a symptom; it is not a diagnosis. Stereotypies may accompany several clinical behavioral syndromes, such as overactivity disorder, anxiety, dysthymia (unipolar or bipolar disorder), dissociative disorders. Stereotypies may also be present in neurological disorders, such as fronto-temporal neurodegeneration (Pick dementia and / or non-Alzheimer non-Pick dementia in people).

I propose a non-exhaustive list of disorders as defined by several authors, following different models (Anglo-Saxon and French-Latin) or paradigms.

Hypersensitivity Overactivity Disorder (HOD) (Pageat 1995)

Diagnosis based on the following signs:

• Lack of control of the bite in a puppy over 2 months of age.
• Lack of capacity to stop a sequence of acts after the consummatory (operant) phase; reappearance of an appetency (begin) phase.
• Hypervigilance associated with production of behavioral sequences in the presence of stimuli continuously present in the living environment of the animal.
• Global reduction of the time of sleep, without alteration of the sleep cycle, nor hypnagogic anxiety.

Accessory symptom:

• Normal sleep time, during the night; but presence of a hypervigilant state.

HOD may include HD as defined in the Anglo-Saxon model.

Hyperactivity Disorder (HD) (Beaver 1994, Overall 1997)

Diagnosis based on the following signs:

• Motor activity in excess, in a constant manner, that does not respond to correction, redirection or restraint.
• Sympathetic signs (increased heart and respiratory rate, vasodilatation)
• Decrease in motor activity with dextro-amphetamine or methylphenidate.

Other signs proposed by B. Beaver (1994)

• The dog is hyperactive, e.g., he seldom sits or lies for more than a few seconds, he tends to bark a lot.
• The dog does not undergo the habituation learning process (Beaver 1994)
• The dog sleeps very little compared to a normal dog.

B. Beaver makes a difference between hyperactivity disorder and hyperkinesis. In the first disorder, the dog is responding to standard tranquilizers such as those in the phenothiazine group. In the latter case, the dog is responding to dextro-amphetamine or methylphenidate.

Permanent Anxiety Disorder (PAD) related Stereotypies (derived from Pageat 1984, 1995)

Diagnosis based on the following principal signs: state of anxiety continually altering the animal's behavior manifested by:

• a state of inhibition
• the production of displacement activities, having evolved towards stereotypies: e.g., stereotyped self-licking behavior (that may induce self-injurious behavior (SIB) producing acral-lick dermatitis (ALD) and acral-lick granuloma (ALD)).
• Absence / disappearance of self-defense (irritation, fear) aggression.
• Disorder beginning at any age.

Constraint (restraint, coercion) Stereotypy Disorder (CSD) (Pageat 1995)

Diagnosis based on the following signs:

• Disorder beginning after the dog has been put in training, has had a restriction in its physical exercise or has been put in a hypostimulating environment.
• Spontaneous stereotypy.
• Normal ethogram when the dog is not producing the stereotypies, with or without hypervigilance.
• Disorder beginning before 1 year of age.

Deritualization Anxiety Disorder (DAD) (Pageat 1995)

Diagnosis based on the following obligatory signs:

• Disorder beginning after a change of social group (in an adult dog).
• Disappearance of the initiative to take social contact.
• Permanent social withdrawal.

Secondary signs:

• Self-defense aggression in case of body contact
• stereotypies based on communication signals (vocalizations, …)
• licking dermatitis
• neurovegetative signs in case of body contact
• ambivalent communication signals

Unipolar (Dysthymia) Disorder (UDD) in adult dogs (Pageat 1995)

Diagnosis based on the following principal signs:

• sudden and prolonged changes in the reactive state, without triggering modification in the environment, characterized by:
• hypervigilance and over-excitability
• hyposomnia
• agitation and/or a loss in the capacity to stop several behavioral sequences

At least 2 facultative signs:

• irritation aggression (and possession aggression)
• stereotypies
• very quick ingestion of the food, followed by regurgitation and re-ingestion
• fixity periods characterized by a fixed gaze toward an object (e.g., wall) for several seconds to minutes.
• Hazardous responses to orders normally well obeyed.

Dissociative Disorder (DD) (Pageat 1998)

Diagnosis based on the following (class 1) signs:

• Disorder beginning between the pre-puberty period and 5 years of age.
• Increasing loss of receptivity to environment.
• Hallucinatory events with constant themes (subjects).
• Production of stereotypies during the hallucinatory phases.
• Hebetude (stunned, dazed) phases with somesthetic activity (grooming, licking, …).
• Premorbid avoiding or impulsive personality disorder.

Accessory (class 2) signs:

• Dilatation of the brain lateral ventricle(s).
• Isolated peaks (points) on the EEG (occipital region).
• Demodex related dermatitis.

(Obsessive) Compulsive Disorder (OCD) related Stereotypy (derived from Overall, 1997, Luescher 1998)

Diagnosis based on the following signs (p. 220, 225, 226):

• Repetitive, (ritualistic), behavior in excess of any required for normal function: e.g., circling, tail-chasing, fence-running, fly-biting, flank-sucking, self-mutilation, hair-biting, air-biting, pica, pacing or spinning, staring and vocalizing, fabric sucking, masturbation, …
• The execution of the stereotyped behaviors interferes with normal daily activities and functioning.

Differential diagnosis from:

• Ritualized (attention seeking) behavior

There are three different groups of dog OCD: conflict, vacuum and stereotypy (p. 223). OCD may resemble and features several symptoms from Pageat's Permanent Anxiety Disorder. Conflict related OCD may be similar in several symptoms to Pageat's Constraint Stereotypy Disorder.

This category is a residual category for disorders that do not meet the criteria for any specific disorder in the classification above.

I think of a Rottweiler presenting a stereotypic jumping on shadows, simulating hunting on small preys, for hours each day.

As a stereotypy is only a symptom (a sequence of acts), there may be several explanations for its occurrence depending on the disorder.

In anxiety disorder related self-injurious licking, Pageat (1995) proposes the following hypothesis:

In unipolar or bipolar disorders (dysthymia), Pageat (1995) found that dopamine antagonists were improving the symptom at day 7, but aggravating it after. He proposed a hypothesis of a general dopaminergic hypoactivity with a hypersensitivity of the whole range of dopamine receptors. These stereotypies were improved by dopaminergic agonists and GABA agonists.

Both hypotheses propose a deregulation with reduction of the dopaminergic activity, particularly in the striato-nigro-pallidum circuitry. This circuitry may be considered as a switch; it is very important to stop a movement. It is composed of 3 neuronal cells in line, a dopamine cell followed by two GABA cells, the last one connected to a motoneuron. Each neuron has spontaneous firing and an inhibitory effect on the following neuron. A lack of dopamine will reduce the efficacy of this switch, inducing prolonged motor activity.

Other stereotypies may be caused by an excess of dopamine activity, like amphetamine induced stereotypies. Dopamine antagonists will reduce these stereotypies, as will serotoninergic drugs inducing an inhibition of dopamine neuronal activity.

An excess of serotonine may induce stereotypies too. It is the case in the serotonine syndrome, particularly in the stimulation of 5HT2 receptors, bringing on a kind of stereotyped "wet dog" movements in rats.

Numerous explanations can be found in other authors publications (Shuster, Dodman, 1998).

The reality of neurotransmitter interactions is really more complex than all hypotheses may propose. Apparently similar symptoms may be improved by different drugs. Why is a tail-chasing or a similar SIB sometimes reduced either by selegiline, either by fluvoxamine? Maybe we will get more answers from a statistical analysis of clinical treatments.

A stereotypy is not physiological, it is a pathology. It depends on a change of the brain neurotransmission chemistry. Medication is the most effective treatment of a stereotypic symptom.

The chosen drug must not relate only to the specific stereotypic movement, but it should be chosen on the basis of:

• the majority of the symptoms of the disorder;
• the hypothetical underlying neuropathological mechanisms of the disorder;
• the clinical experience of the practitioner.
• The urgency of the improvement of the symptom (vs. euthanasia)

Drugs interacting with opioid receptors are of limited value. Clinically, one has basically four choices:

• Dopamine activation and/or regulation.
• Dopamine antagonism.
• Serotonine activation and/or regulation.
• GABA activation

1. Dopamine activation and/or regulation.

• HOD related stereotypies
• PAD related chronic stereotypies (especially on SIB such as found in ALD and ALG).
• DAD related stereotypies.
• UDD related stereotypies.

2- Dopamine antagonism.

3- Serotonine activation and/or regulation.

4- GABA activation.

As per definition a stereotypy does not have any internal regulation and is only modifiable by external forced stimulation; there may not be a lot of behavioral techniques available to modify it.

The use of mechanical devices , such as Elizabethan collars, bandages, etc. has to be restricted to what is absolutely necessary; they are not therapeutic techniques.

One has to modify the etiology when it is known, like in CSD. The stressor, e.g. the hypostimulating environment or the coercion training technique, must be modified. Bring good living welfare conditions ( ecological therapy ):

• increase the level of stimulation in the environment if it is hypostimulating,
• reduce punishment, coercion, constraint & negative emotions in training techniques.

Use ethological therapies as much as possible. In DAD, if the system is suffering from deritualization, one has to create new appeasing rituals.

In HOD, the dog has to learn how to control its biting and movements. Imitate the mother or another educating adult dog who teach the puppy to behave:

• grab the puppy on the head or neck (or bite it), force it down until it stays quiet for an increasing time.
• In place of grabbing the puppy, one may give it a tap on the head or nose when it is overactive. This has to be done without anger. And the tap has to be sufficient to stop the behavior. Then put a new controlled behavior in place and reward it.

Neuropathology hypotheses of stereotypies are very complex. But the clinical management of stereotypies is easier if one makes a good diagnosis on all the accompanying symptoms.

President of the European Society of Veterinary Clinical Ethology (ESVCE).
President of the Belgian Veterinary Behavior Group (GERC).