Clinical management of stereotypies in dogs
© Dr. Joël Dehasse, behaviourist veterinarian, Brussels, Belgium
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:
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).
Behavior disorders accompanied by stereotypies
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:
HOD may include HD as defined in the Anglo-Saxon model.
Hyperactivity Disorder (HD) (Beaver 1994, Overall 1997)
Diagnosis based on the following signs:
Other signs proposed by B. Beaver (1994)
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:
Constraint (restraint, coercion) Stereotypy Disorder (CSD) (Pageat 1995)
Diagnosis based on the following signs:
Deritualization Anxiety Disorder (DAD) (Pageat 1995)
Diagnosis based on the following obligatory signs:
Unipolar (Dysthymia) Disorder (UDD) in adult dogs (Pageat 1995)
Diagnosis based on the following principal signs:
At least 2 facultative signs:
Dissociative Disorder (DD) (Pageat 1998)
Diagnosis based on the following (class 1) signs:
Accessory (class 2) signs:
(Obsessive) Compulsive Disorder (OCD) related Stereotypy (derived from Overall, 1997, Luescher 1998)
Diagnosis based on the following signs (p. 220, 225, 226):
Differential diagnosis from:
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.
Stereotypic Movement Disorder (SMD), not otherwise specified.
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:
Licking à activation of the serotoninergic descending fibers à reduction of pain sensitivity à increased self-licking à liberation of beta-endorphin à deregulation and decrease of noradrenergic and dopaminergic transmission à increased rigidity of the displacement activity sequence à leading to a stereotyped activity.
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:
Drugs interacting with opioid receptors are of limited value. Clinically, one has basically four choices:
The drug of choice is selegiline, given at 0,5 mg/kg, once a day. It is an MAO-B inhibitor, phenylethylamine activator, and cathecholamine reuptake inhibitor.
Selegiline is most effective on
Selegiline is indicated as a first choice to treat SMD, because of its lack of side effects.
2- Dopamine antagonism.
The drug of choice is risperidone; it blocks receptors for both serotonin and dopamine (specifically, 5HT2 and D2 receptors). It also blocks central adrenergic receptors.
It will be most effective in Dissociative Disorder related stereotypies, particularly in tail-chasing and circling German shepherds or other breeds. I also have a positive effect in a fly-snapping Greyhound. Treatment is for life.
The dosage is between 0,5 to 1 mg per square yard (around 33 kg), once a day.
3- Serotonine activation and/or regulation.
Several serotoninergic drugs have two following effects; they first increase the serotoninergic transmission, aggravating the emotional instability and displacement activity (SIB) symptoms, then after 3 to 6 weeks, they improve the symptoms, due to the putative down-regulation effect on post-synaptic receptors. The aggravating effect is reduced with drugs having a sedative side effect like clomipramine (antihistaminergic) or fluvoxamine (serotoninergic).
There are a lot of serotoninergic drugs like the unspecified serotoninergic (and noradrenergic) activating tricyclics (clomipramine, amitriptyline, etc.) and the more specified serotonine selective reuptake inhibitors (SSRI). They will be most effective in recent OCD and PAD related stereotypies.
The dosage of clomipramine and fluvoxamine is between 0,5 and 2 mg/kg twice a day, fluoxetine between 1 to 4 mg/kg once a day.
Several serotoninergic (5HT1) drugs have an inhibitory effect on dopamine neurons; this may not be the case with small dosages of fluoxetine, that may have an agonistic effect on dopamine transmission via 5HT2 neurotransmission. The antidopaminergic effect of serotoninergic drugs may be enhance by the addition of a dopamine antagonist like pipamperone, at the dose of 10 to 20 mg/square yard, twice a day.
4- GABA activation.
GABA-ergic agents may help restore the ending phase of a behavioral sequence (stop phase). The best drug for this purpose is carbamazepine, used in a long acting pharmaceutical form, twice a day at the dosage of 20 mg/kg. However, this drug is not very effective.
I have combined carbamazepine to selegiline to enhance improvement. It may also be combined with fluvoxamine, but then the dose of carbamazepine has to be reduced at least by two.
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 ):
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:
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.
Beaver B. The Veterinarian's Encyclopedia of Animal Behavior. Iowa State University Press / Ames, 1994.
Luescher UA. Pharmacologic treatment of compulsive disorder. In Dodman N, Shuster L, eds: Psychopharmacology of animal behavior disorder. Blackwell science, 1998: 203-221.
Overall KL. Clinical behavioral medicine for small animals. Mosby, 1997.
Overall KL. Self-injurious behavior and obsessive-compulsive disorder in domestic animals. In Dodman N, Shuster L, eds: Psychopharmacology of animal behavior disorder. Blackwell science, 1998: 222-252.
Pageat P. Etude clinique et expérimentale des troubles du comportement chez les carnivores domestiques. Thèse présentée à l'Université Claude Bernard de Lyon, 1984.
Pageat P. Pathologie du comportement du chien. Editions du Point Vétérinaire. 1995.
Pageat P. Le syndrome dissociatif chez le chien. Proceedings des IV èmes journées du GECAF, Morzine, 7-9 janvier 1998.
Shuster L, Dodman NH. Basic mechanisms of compulsive and self-injurious behavior. In Dodman N, Shuster L, eds: Psychopharmacology of animal behavior disorder. Blackwell science, 1998: 185-202.
Dr Joël Dehasse