Friday, May 24, 2013

By Michelle Gerhard Jasny V.M.D.
Published: April 9, 2009

You may have met a cat like Norman. A seemingly normal feline, he jumps up on the couch for attention. You pat his head, scratch behind his ears. He leans in, purring vociferously. "What a nice kitty," you think, moving your hand down his neck. But as you reach to touch his back, Norman's skin begins to ripple. His eyes dilate. Without warning he wheels around, fiercely sinks his teeth into your hand, then lets out an unearthly yowl and races off madly around the house.

People experiencing this phenomenon for the first time often think Norman has a back injury or that they hurt him in some way to elicit such a reaction. They may decide Norman has gone psycho or that he is just an evil kitty. Well, could be, but the more likely explanation is that Norman has an odd affliction known as feline hyperesthesia syndrome (FHS).

FHS goes by many other names: psychomotor epilepsy, neurodermatitis, pruritic dermatitis of Siamese, rippling, rolling, or twitchy skin disease. Affected cats exhibit a wide range of behaviors which may include rolling, crouching with hindquarters stuck up in the air, excessive licking, biting, or fur-pulling along the back and tail, rippling skin, muscle spasms, yowling, running, jumping, and possible hallucinations. Seen most commonly in cats between the ages of one and five, it can occur at any age and in any breed, although Siamese, Persians, Burmese, and Abyssinians have a higher incidence than your typical alley cat. There is not one specific cause, but it is thought to be a unique behavioral response to a variety of different factors.

The first possibility is that Norman has some kind of skin condition that makes his back highly sensitive to touch. Fleas, food or inhalant allergies, bacterial, fungal, or parasitic infections are all proposed causes. The second possibility is that Norman has a musculoskeletal problem causing back pain such as inflammatory diseases of the nerves or muscles, or intervertebral disk disease. The third possibility is that Norman has a brain lesion that is creating the bizarre behavior, such as a brain tumor, or an unusual form of epilepsy. All of these options can be pursued diagnostically by your veterinarian with a thorough physical and neurologic examination, followed by tests. Lots of tests. Blood work, fungal cultures, skin scrapings, radiographs, allergy tests, hypoallergenic food trials, MRIs, CAT scans, muscle biopsies. Maybe you'll opt to do all of these, or maybe just the most basic.

"My cat is freaking out," a client once called me, hysterical. "He's leaping around the house like a wild animal." The cat, Alfred, had been acting increasingly agitated over the last few days, she explained. Then, right before she called, kitty had come bounding in from the hall, jumped frantically onto the table, then catapulted himself to the top of the refrigerator, sending papers flying and dishes crashing. "He's acting like he's on fire, like he's afraid to touch the ground with his feet," she cried.

After I calmed the owner and made suggestions for how to safely corral the cat, she managed to get Alfred into the carrier and bring him in for an exam. It was a five-second diagnosis. "Do you have wall-to-wall carpet?" I inquired. The owner nodded, mystified. "Is Alfred the only animal in the house?" I continued. Nodding again, she added "My son's golden retriever used to live with us, but he took her back to college last month."

Alfred's problem was simple. The house was infested with fleas - fleas that prefer to live on pets rather than people. Alfred didn't have feline hyperesthesia syndrome. He wasn't crazy. He was just trying to stay off the carpets where hundreds of new fleas were hatching out and attacking him every time he stepped in the house. A few doses of total body flea control products, plus aggressive flea treatment of the environment, resolved Alfred's strange behavior. But not every case has such a simple explanation. We can run every test in the book and still not come up with a medical explanation for FHS. That leaves us with the group of kitties, like Norman, with what we call behavioral feline hyperesthesia syndrome.

When an animal experiences anxiety or stress, it may respond with a seemingly unrelated behavior, such as grooming. A person might bite his nails or twirl her hair. A cat might lick itself. Given enough stress, this may turn into excessive, exaggerated grooming. People are not immune. Think about expressions like, "I was so upset I wanted to tear my hair out." Over time, the behavior may appear to occur with little or no external provocation. In other words, a learned behavior develops into a habit, then into a compulsion. More extreme reactions in people might manifest as something like trichotillomania, a disorder in which a person compulsively pulls out his or her eyelashes. In cats, where no underlying medical explanation can be found for the bizarre actions of FHS, it is then presumptively classified as a compulsive behavior disorder.

Treatment can be frustrating. We start by treating potential underlying causes with flea control products, hypoallergenic diets, corticosteroids, and/or anti-seizure medications, then move on to behavior modification. Punishing Norman will only exacerbate the situation by increasing his stress. Instead, he needs a very structured environment with predictably scheduled meals and supervised play activities, avoiding situations that trigger the behavior such as touching, rubbing or scratching his back. Finally, if none of this solves the problem, we can try psychotropic drugs. From the Greek meaning "turning the mind," psychotropic is a big word that just refers to any medication that affects the mind, emotions, or behavior, in this situation primarily antidepressants and anti-anxiety medications. As in people, these medications need to be given long-term and combined with behavioral therapy. None is officially approved by the FDA for this purpose in cats, and your veterinarian will want to discuss with you the risks as well as the benefits, but if Norman is going psycho and unpredictably attacking your dinner guests, it makes sense to try medicating him.