Feline hyperesthesia syndrome (FHS) is also known by a variety of other names including rolling skin disease, neurodermatitis, neuritis, psychomotor epilepsy, and pruritic dermatitis of Siamese. As evidenced by these names and use of the term syndrome, FHS does not have a single cause. In fact, in order to diagnose FHS, ruling out other conditions that resemble FHS is often required; these conditions are related to dermatology, neurology and behavior. Only by ruling out conditions relating to skin and nervous system involvement can this condition be labeled a behavioral disorder.

Cats Commonly Affected

FHS can occur at any age but is commonly seen in cats from 1 to 5 years of age and occurs equally in either sex. While all breeds can be affected, Siamese, Burmese, Persian and Abyssinian cats are more commonly affected.

Symptoms

Affected cats often show rippling or rolling skin along their back. Pain can sometimes be apparent when pressure is applied to the muscles along the back. Dilated pupils are usually seen during bouts. The cat will commonly stare at his tail, and then subsequently attack the tail and/or his sides. It’s not uncommon for the cat to bite his tail base, forelegs and paws. The cat will often run around wildly while vocalizing. Cats who are normally calm may be aggressive to humans or other cats, while aggressive cats may become more affectionate. The behavior may be triggered by petting or stroking the fur and it most commonly occurs in the morning or later in the evening.

Diagnosis

Diseases of skin, nervous system, and muscles can resemble the behavioral signs of FHS, so these conditions need to be ruled out before a behavioral diagnosis can be made. Diagnostic procedures include a physical exam, neurologic exam, blood and urine lab work, and x-rays of the spine. Depending on these results, further tests can include checking for or treating skin parasites, such as fleas and mange; ringworm (a skin fungus); skin and/or muscle biopsy; CT/MRI scans; skin allergies; and use of anti-seizure medication. The decision on which tests to run and in what order depends on the approach the pet owner and veterinarian decide to take. In some cases these procedures can be done sequentially until beneficial results are achieved. In other cases tests can be done at the same time to achieve a more rapid conclusion. If none of the above approaches result in an improvement, then a presumed diagnosis of behavioral feline hyperesthesia can be made.

FHS is commonly considered to be a compulsive disorder and can result in self-injurious behavior. One proposed trigger of the behavior is a consequence of displacement activity. Displacement behavior occurs as an alternative to two other conflicting behaviors. An example might be a cat who desires to eat from a bowl but is prevented from doing so by an aggressive cat. The competing motivations are hunger and fear, causing the cat to be simultaneously motivated by the desires to eat and escape. As a consequence, the cat might indulge in an unrelated but species-appropriate displacement behavior such as grooming. If this conflicting situation persists over a prolonged period, the cat may engage in the displacement behavior even when the competing motivations are gone, at which point the behavior is defined as compulsive. The current theory about what causes the compulsive behavior is that the cat doesn’t have enough serotonin, a chemical that transmits nervous signals in the brain and which reduces the brain’s ability to inhibit these behaviors. An increased serotonin level reduces the incidence of compulsive disorders and is why selective serotonin reuptake inhibitors (SSRIs, a class of antidepressants) are used to treat compulsive disorders such as FHS.

Treatment

As with many behavior problems in companion animals, treatment combines behavior modification protocols and the use of psychoactive pharmaceuticals. Behaviorally, the goal is to create a stable and consistent environment for the cat. This can be accomplished in the following ways:

• Provide regular feeding in order to provide a more predictable source of food.
• When managing dogs with a compulsive disorder, one frequent recommendation is to maintain consistent interactions by always having the dog respond to the owner’s commands: you ask the dog to sit and the dog sits, after which a treat is given as a reward. The same can be done with cats.
• Provide regular play sessions using target-type toys (feather toys, for example).
• Do not use punishment for this behavior as it will increase the cat’s conflict and stress, likely resulting in an increase in the problem behavior.
• Anticipate triggering situations that result in the behavior and redirect to more appropriate behaviors (such as training or playing).

Pharmaceutical Intervention

It is important to recognize that there are no FDA-approved medications for treating any compulsive disorder in pets, including FHS. As a consequence, be aware of potential risks versus the possible benefits of these medications. It is always wise to perform appropriate lab testing (as described above) to confirm the pet’s health status before to using these medications. It is also helpful to repeat those lab tests approximately 4 weeks after starting medication.

In addition, some of these medications will inhibit the liver’s ability to metabolize other medications that the pet may be taking. As a consequence, care should be shown when using medications that rely on the liver to be metabolized, such as phenobarbital, carbamazepine, benzodiazepines, and tricyclic antidepressants. Finally, these drugs should not be used in combination with each other or with other drugs that increase serotonin levels

(monoamine oxidase inhibitors such as selegiline or amitraz, other SSRIs such as paroxetine or sertraline, as well as TCAs like amitriptyline, imipramine and doxepin).

The following are examples of medications that can be used in treating feline hyperesthesia syndrome. These medications should only be used under the direction of a veterinarian who is comfortable with their use, and there should be close communication between the veterinarian and pet owner to monitor progress and side effects.

Selective Serotonin Reuptake Inhibitors (SSRIs)

Fluoxetine
Paroxetine

Side Effects: sedation, lack of appetite, irritability, vomiting, diarrhea

Tricyclic Antidepressants (TCAs)

Clomipramine

Side Effects: sedation, physical and mental impairment, possibility of heart arrhythmias if predisposed, lowered seizure threshold if seizures are pre-existing

Benzodiazepines (BZDs)

Lorazepam
Oxazepam

Side Effects: sedation, incoordination, and temperament changes.

It is acceptable to combine the use of SSRIs or TCAs with one of these BZDs if response to either the SSRI/TCA or the BZD alone is insufficient.

When using these medications in cats, consider beginning at the lower end of the dose range and then increasing upwards as needed to achieve the desired response. In this way you can minimize the potential for serious side effects.

Treatment can be maintained for 4 to 6 months with the behavior occurring at an acceptable level before gradually reducing the dose (reduce by 25% every 1-2 weeks). Continue the weaning process until the cat is either completely off the drug or until the behavior reoccurs. At this point, return to the previously effective dose and continue for a longer period before trying to wean again. This may mean attempting another reduction 4 to 6 months later or it may result in lifelong use. If using combination therapy (SSRI/TCA with a BZD), wean off one medication at a time in order to determine which drug is responsible if symptoms return as dosage is reduced.