Animal Instincts

The Haunted Feline

A colleague sent me a video of a grayish domestic short-hair cat hunkered down on the stainless-steel veterinary examination table, seemingly waiting for something to happen … and then suddenly it did. Alarmed, the cat swung its head over its left shoulder to look at something only it could see. The object, or whatever it was, apparently descended rapidly, following a parabolic course, causing the cat to duck before it disappeared from the top right corner of the room.

The cat’s mysterious behavior was caught on tape several times within a few minutes. One M.D. who saw the video at a talk I was giving asked if I had considered treating the cat with an antipsychotic medication, because she thought the cat was schizophrenic.

In truth, I was not sure what was causing the problem. Later, I saw a different cat displaying identical behavior, as well as other, more telltale symptoms. The diagnostic fog was clearing: both cats suffered from feline hyperesthesia syndrome (FHS).

FHS is a bizarre condition that affects primarily Oriental breeds. In its classical form, it manifests as bouts of agitation in which the pupils dilate widely, the skin ripples, and the cat grooms itself frenetically along the spine or the base of its tail. The syndrome can include tail chasing and tail biting, sometimes to the point of self-mutilation. Or the cat may suddenly appear distressed and flee some unseen enemy, like the UFO-sighting cat in the video.

The cause is equivocal. Some experts claim FHS is set off by a viral inflammation of the muscles on either side of the spine. Others claim it is a type of compulsive behavior or a manifestation of partial seizure activity. I think the explanation lies somewhere between the last two hypotheses. On the one hand, the condition is sometimes helped by anticompulsive drugs like Prozac. On the other, FHS sometimes progresses to convulsions and often responds to anticonvulsant therapy.

Also, there are many parallels between FHS and human epilepsy. People who suffer from either partial seizures or grand mal attacks frequently report feelings of anxiety or fear. Some try to run away from an unseen tormentor, and others experience visual or auditory distortions. Certainly, if a cat is experiencing fear, confusion, and visual disturbances, it would exhibit the kind of behavior we see with feline hyperesthesia. Some human epileptics become uncharacteristically aggressive in the period surrounding a seizure—just as some cats do during bouts of FHS. Partial seizures, too, can make people aggressive, a problem known as episodic dyscontrol (dogs have a similar seizure-related problem we call “rage”).

To resolve the uncertainties about what causes FHS, we are planning to conduct electrophysiological studies on cats that have the syndrome, using equipment that is far more sophisticated than any employed before. If FHS does stem from a localized electrical brainstorm, we should observe changes in those regions of the brain controlling emotions, perceptions, and memory—as occur in people with partial seizure disorders. The more we research animal behavior problems, the more similarities we find between our veterinary patients and humans. That should come as no surprise, really, considering that we mammals are all in this together.

A word of caution to cat lovers. Do not think your moggy has FHS just because its pupils sometimes get large or because it grooms its back or has occasional skin ripples. Diagnosable FHS is an extreme behavioral condition that leaves little doubt that something is seriously wrong with your cat. True, there may be milder, “sub-threshold” expressions of FHS that fly under the diagnostic radar, but as long as they cause no obvious dysfunction they can probably be written off as a character trait.

My grown son has a Siamese that occasionally acts wild and tears around the house. His cat also becomes wild-eyed from time to time and shows some skin rippling. “Does he have FHS?” my son asked. “Maybe a little,” I replied. As with most other behavioral disorders, diagnosis of FHS is always a clear yes, no, or maybe.

NICHOLAS DODMAN directs the Animal Behavior Program at the Cummings School of Veterinary Medicine. He is the editor of Puppy’s First Steps: The Whole Dog Approach to Raising a Happy, Healthy, Well-Behaved Puppy (Houghton-Mifflin, 2007).