Information about Feline Hyperesthesia Syndrome, FHS

Feline Hyperesthesia Syndrome/FHS, is a rare condition in which cats have attacks of twitching in the skin on the back, tail and hip area. The cat licks and bites quickly in the area, seems agitated and very bothered by the attacks. The nervous system, the neuromuscular system and the skin is affected by this condition.

Symptoms

- The symptoms of FHS are typically seen in episodes that can last from a few seconds to several minutes. The cat will behave normally between episodes:

- Twitching of the skin

- The tail whips violently and quickly

- The cat repeatedly and quickly bites and licks the back, tail and hip area

- Cats with FSH often have large pupils

- They seem excited

- They show unpredictable and unusual behaviour that is out of context with what is going on around the cat

- Stimulating the muscles in the back can irritate some cats and may trigger an episode

- The hairs may be damaged and the follicles may have fallen out due to the cat's excessive grooming

A physical examination usually shows no neurological problems or major abnormalities.

Are some breeds particularly predisposed?

Symptoms are seen in cats of all ages and can develop in cats of all breeds. Purebred cats, especially Siamese, Abyssinian, Burmese and Himalayan cats are thought to be particularly predisposed to developing the syndrome.

Physical examination is important:

As there is no known physical cause behind the syndrome, it is difficult to diagnose and the diagnosis is primarily based on the cat's behavioral history and the exclusion of other factors/diseases that may cause similar symptoms. There are no specific tests that can provide a definitive diagnosis.

Other diagnoses that can help rule out FHS, and which it is obviously important to rule out, include:

- Ectoparasites

- Allergy

- Other skin problems

- Some suspect an adverse reaction to spot-on antiparasitic agents may be a triggering factor but this has not been proven. 

- Pain in the back or back end. X-ray is recommended

- Assess for the possibility of the metabolic disease hyperthyroidism, which can make the cat hyperactive. Hyperactive cats are thought to be at greater risk of developing FHS

- Intracranial diseases that causes behavioral changes or convulsions/epileptic seizures. Scans, such as MRI, may help identify such neurological problems

Background

FHS is a rare syndrome and the exact cause is not known. It is thought that FHS may develop due to an underlying behavioral problem (eg OCD), seizures or other neurotic problems.

Certain breeds as well as nervous or hyperactive cats are thought to be at greater risk of developing FHS.

Environmental stressors may also trigger the syndrome. It is also suspected that some spot on parasite treatment can trigger transient episodes. 

It is believed that there are many factors that contribute to the symptoms associated with FHS.

Treatment

There is no specific medical treatment available that can cure FHS. However, different types of medicine witch have an effect on neuropathic pain, epilepsy and anxiety may have a beneficial effect and may keep the attacks down.  These types of medication require a prescription and must of course be prescribed by a veterinarian after a thorough investigation. 

Environmental elements or events in the home that seem to trigger episodes should be avoided. If the cat injures itself by licking itself a lot, a barrier collar or tail bandage may be necessary.

Behavioral counseling

Behavioral modification, such as stress reduction, environmental optimisation, activity, pheromone therapy, stress- and anxiety-reducing supplements, etc., can be helpful in at least reducing the problems in some cats. A combination of veterinary treatment of the physical aspects of the syndrome and behavioral counseling can therefore be recommended.

Prevention of FHS

Because the exact cause of the syndrome is not known, a mainly behavioral measures can used to prevent and/ or minimise the symptoms of the condition. Optimising the environment, reducing sources of stress and ensuring good daily activity of the cat can, among other things, is recommended - as well as, of course, following the annual health checks at the vet, so that any physical problems can be detected and treated in time.