A cat with feline hyperesthesia.

Feline Hyperesthesia (FHS)

Ever since the earliest days of human-cat interactions, we’ve puzzled about the unique and confusing behavior of cats. Throughout history, this has often given them a reputation for being divine, mystical, or even possessed.

As devoted cat companions, we often ask ourselves which kitty quirks are normal, and which could signal a problem, like pain, stress, or illness. Nothing exemplifies the need to understand normal cat behavior more than the poorly understood medical condition, Feline Hyperesthesia Syndrome.

Clinical Signs of Feline Hyperesthesia Syndrome (FHS)

Possible Causes

FHS tends to appear for the first time in mature cats. No one really knows what causes FHS, but there are a few possibilities:


Many well-understood medical conditions can cause clinical signs that are similar or even identical to FHS. Because there is no definitive test that confirms FHS, it is important that veterinarians eliminate other possible causes for the cat’s unusual behavior. Conditions like parasites, hyperthyroidism, spinal cord injuries/disease, dermatological disease, and others must be investigated and ruled out. If the clinical picture fits FHS and no other illness has been identified, a positive response to treatment for FHS allows the condition to be diagnosed. To this end, your veterinarian will obtain a careful behavioral history regarding your cat, perform a thorough physical examination, run diagnostic blood and skin tests, and take spinal x-rays.


Optimize the affected cat’s environment to minimize stress (stress could be a factor in every expression of the syndrome). Recommendations include:

Behavior-Modifying Therapy

Drugs that help are potent serotonin-enhancing medications. In the brain, the neuromodulator, serotonin, stabilizes mood and has anti-obsessional and anti-aggressive effects. Drugs that have been found effective include clomipramine (Clomicalm®) and fluoxetine (Prozac®) Your vet may also recommend other potent serotonin-enhancing drugs, including paroxetine (Paxil®), sertraline (Zoloft®), and fluvoxamine (Luvox®). These drugs take a while to become effective. Typically, little to no improvement is seen for the first three weeks. Then, by four weeks, owners might notice a 50% reduction in the incidence and severity of bouts of FHS. Typically, the improvement may reach 75% at eight weeks, 85% at 12 weeks, and 95% by sixteen weeks.

Complete cure is rare and most cats need to remain on medication long term to suppress the FHS behavior. Pet owners can be assured that medical complications of treatment are rare, and the benefits of treating the condition generally outweigh the risks. Nevertheless, it is important for affected cats to be monitored regularly by the veterinarian, and complete appropriate bloodwork at least once per year. If you’re concerned about costs related to treatment of behavioral issues, pet insurance may be able to help. Click here to learn more.

Anti-Convulsant Therapy

When stress reduction and behavior modifying therapy is ineffective or only marginally effective, anti-convulsants can be administered. One common treatment choice is Gabapentin. Gabapentin has a multi-modal benefit of reducing stress in cats, addressing nerve-generated pain, and suppressing seizure activity. This medication is given by mouth, so it can be administered to cats at home. Unfortunately, many cats don’t like the taste of gabapentin, so it’s important to work with your veterinarian to find a flavor and texture option that works well for your pet.


With appropriate environmental and pharmacologic treatment, affected cats can often be rehabilitated and can lead a normal life. When treated, most appear much happier than they were previously while suffering the full brunt of their affliction.