In veterinary medicine, the term stereotypy has been used traditionally to define behaviours that are repetitive, constant, and appear to serve no obvious purpose. Stereotypies and obsessive-compulsive disorders are currently used interchangeably in the behavioural literature by some authors, whereas others refer to them as stereotypies, and finally, a few do not allude to either term. Considerable discussion occurs when the question “can animals obsess?” is raised. It appears that animals perceive concern and anxiety, thus it is possible that they can obsess. Separate from the obsession issue is the issue of relative intensity. Is the behaviour simply excessive or is it a manifestation of an obsessive-compulsive disorder? It is also possible that an excessive behaviour and an obsessive-compulsive behaviour are merely two points on a blurry continuum.
Obsessive-compulsive disorder is probably responsible for some unknown proportion of companion animal behavioural conditions. The role of stress (actual or perceived) has largely been ignored in veterinary medicine. Obsessive-compulsive behaviours interfere with the animal’s ability to function in its social environment. A competing stimulus may change or abort the behaviour but time spent in the activity gradually increases. The abnormal behaviour gradually displaces normal behaviour and the actual behaviours change in qualitative features (intensity profile).
Behaviours evinced as a result of feline “stress” or anxiety include changes in appetite (decrease or pica), changes in grooming, changes in elimination (spraying and non-spraying marking), changes in social interactions (rubbing, bunting, vocal communication), and changes in activity (degree and location). Some examples of obsessive-compulsive disorders in cats listed in the literature include over-grooming, barbering, feline hyperesthesia, self-mutilation, tail chasing, pica, wool and fabric chewing, and wool sucking. Not all authors agree that these conditions are truly obsessive-compulsive disorders.
FELINE HYPERESTHESIA, OVER-GROOMING, AND SELF-MUTILATION
Feline hyperesthesia syndrome has been variously called rolling skin disease, neuritis, twitchy cat disease, and atypical neurodermatitis. The behaviours demonstrated can include those mimicking estrus or biting at the tail, flank, anal or lumbar areas (sometimes with resultant barbering and self-mutilation); or skin rippling and muscle spasms/twitching (usually dorsally), often accompanied by vocalisation, running, jumping, hallucinations and self-directed aggression. Not all cats exhibiting these behaviours self-mutilate, but those that do can exhibit a range of mutilation from excessive licking, to plucking (trichotillomania), barbering, biting, and chewing that lead to skin lesions. Regardless of the degree of behavioural change, owners report that it is difficult to distract the cat from the behaviour. The behaviour sequence can vary. Cats might twitch and then focus on a part of the body to lick or chew. Or they might be grooming, start to twitch, and then exhibit more furious behaviours. Painful and dermatological causes MUST be ruled-out before even considering the possibility of a behavioural disorder. Environmental and social stresses have been associated with these disorders and range from readily apparent (skin conditions including food allergy, atopy, or fleas; the addition or loss of another cat; intercat aggression; the addition or loss of a human with attendant changes in attention); to indiscernible exogenous cues. Cats may also perceive truly endogenous cues (anxiety can be the result of altered neurochemistry/neurotransmission and can therefore also be endogenous).
FABRIC EATING, SUCKING, AND CHEWING
Obsessive-compulsive disorder can manifest itself as an eating disorder. Fabric eating, chewing, and sucking may not be associated with any nutritive considerations relevant to eating disorders and may represent obsessive-compulsive disorders associated with stereotypic chewing or mouth movements. There is no unanimity among veterinary behaviourists/non-veterinary behaviourists as to causes and label of these behaviours. Oriental breeds are among the most common breeds in which these conditions are reported. In one study (UK) of 152 fabric-eating cats, 55% were Siamese, 28 % were Burmese, and 11% were crossbreeds. Typical age of onset was two to eight months. Males were as likely as females to present with the problem. Most animals were neutered. Ninety three percent started with wool and moved on to other fabrics (64% also ate cotton and 54% ate synthetic fabrics). Another author claims that this behavioural trait is generally restricted to the Siamese breed and the wool chewing begins at about the time of puberty. This author states that most cats seem to give up wool chewing within one year. Data compilation on this condition has not yet been performed in the United States. Some cats will progress to ingesting plastic, rubber and even wood.
The exact cause of the behaviour is unknown. Some authors have suggested increasing the amount of fibre in the diet, whereas others have given the cat gristly meat attached to large bones. Others have made an unwanted piece of woolen garment available to the cat generally at meal times. In some cats, the onset of pica (ingestion of non-digestible items) is triggered by a stressful event, for example, moving from the breeders to a new home or the addition of another cat to the household. Close attention should be paid to social interactions between household cats. Aggression can be present without overt signs. Cats will posture and can threaten other cats silently.
Wool sucking may be a behaviour that is “left over” from the prolonged 6-month suckling period common in feral cats. Cats that are weaned particularly early seem to be over-represented in that population. Again, different authors do not agree on whether wool sucking and wool chewing are distinct or related problems. Data compilation is lacking.
TREATMENT OF OBSESSIVE-COMPULSIVE DISORDERS
Treatment protocol for obsessive-compulsive disorders should include an increase in activities that compete with the repetitive behaviours. If the cat likes to chase and play, owners are encouraged to interact more with their cats and actively play with them. Cats can also be trained to come, to sit, to jump up, etc. Food rewards are used for the training. Feral cats spend a considerable amount of time searching for food. Owners can hide some dry food and special food treats in the environment so that the cat has to actively find the food. Cats should not be punished. Most owners are unable to catch the cat in the act every single time. They are unable to apply punishment correctly, which results in increased anxiety. If anxiety is truly the underlying cause of these behaviours, the situation will worsen.
Occasionally, some animals perform behaviours that attract attention. Unwanted behaviours should not be “rewarded” with attention. If these cats can be interrupted with an unusual sound, owners can then ask them to do another behaviour (e.g., come, sit) and reward them for doing so (food treat or attention). Environmental situations that are “stressors” and potentially contributing to the problem (intercat aggression, lack of activities for the indoor cat, changes in owner attention to the cat) need to be addressed.
Medication to decrease anxiety is usually prescribed for at least 12 weeks before deciding whether full effects are beneficial. Some patients require a higher dose. Others require more frequent administration. In people treated for obsessive-compulsive disorders, a given drug will be tried for at least six months before changing the medication or adding another drug. Clomipramine (Anafranil®, Clomicalm®), a tricyclic antidepressant (TCA) has been traditionally used for treatment of obsessive disorders in humans. In the United States, clomipramine (Clomicalm®) is labeled for use in dogs to treat separation anxiety, whereas in Canada and Australia, it is also labelled to treat obsessive-compulsive disorders of dogs. In the past 15 + years, selective serotonin re-uptake inhibitors (SSRIs) such as paroxetine (Paxil®), sertraline (Zoloft®), fluoxetine (Prozac®), citalopram (Celexa®), fluvoxamine (Luvox®) have been introduced and evaluated for the treatment of obsessive-compulsive disorders in people. Fluoxetine, sertraline, fluvoxamine and paroxetine have demonstrated efficacy in the treatment of obsessive-compulsive disorders. In contrast, clomipramine, though efficacious, is often associated in people with substantial adverse events, particularly anticholinergic effects. Clomipramine was effective in controlling the signs of anxiety-related and obsessive-compulsive disorders in 10 of 11 cats and was well tolerated. The average maintenance dosage was 0.3 mg/kg once daily. Four cats became lethargic at higher doses.
Although many of these drugs have been used in cats and dogs to treat anxiety-related behavioural problems, these drugs are not labelled for use in animals and there is still very little data available on the efficacy of these medications for the treatment of obsessive-compulsive disorders in cats (or dogs). Routine complete blood cell count (CBC) and biochemistry panels are always performed prior to prescribing any psychotropic drug. Therapy may be necessary for months and perhaps even years. Blood tests are repeated yearly in young patients and twice yearly in older patients. Dosage for fluoxetine (Prozac®) in cats is 0.5 mg/kg orally once daily. Paroxetine (Paxil®) is prescribed at a dose of 2.5 mg per cat once daily. Potential side effects with clomipramine can include vomiting, constipation, decreased appetite or anorexia, dry mouth, tachycardia, arrythmia, and sedation. Side effects associated with selective serotonin reuptake inhibitors can also include sedation, decreased appetite, anorexia, vomiting, and diarrhea. Other drugs have been used to treat obsessive-compulsive disorders in cats and some examples include amitriptyline (Elavil®), diazepam (Valium®), clorazepate (Tranxene®), and alprazolam (Xanax®). In summary, each patient presented with a tentative obsessive-compulsive disorder needs to be fully worked-up medically and behaviourally in order to determine the best drug option for that given case as well as address all other contributing factors.
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