I remember the first time I saw a cat with feline hyperesthesia syndrome (FHS).  It was a pretty bizarre clinical picture.  The cat would start twitching its back muscles and ripples would run up and down the spine.  The eyes would be completely dilated and it would act possessed, often trying to attack.  I was certainly perplexed by this bizarre disease.

FHS has been an enigma in the veterinary field and there have been several theories as to what causes it, but about the only thing that has changed over the last 50 years is the name of the disease.  Years ago, we called it “Creepy Crawly Disease.”  Then, it was changed to “Twitchy Cat Disease” and now, it is referred to as Feline Hyperesthesia Syndrome.  The profession still does not have a clue as to its cause.

Originally, there was a belief that it was a skin problem, maybe associated with skin allergies.  The skin did seem to play a factor, since most of the cats showed the twitchy skin symptoms.  Most of the time, vets would give steroids in hopes that if it was allergy related, there would be improvement.

After being frustrated with no explanation or treatment, I decided to do some self-studies myself.  The fact that the cat would be perfectly normal and then acutely go into an episode of twitching, dilated eyes, aggressive biting and then returned to normal in 30-60 seconds seemed an obvious pattern.  The only thing I could correlate to this pattern is an atypical seizure pattern.  Seizures, as a rule, would have a sudden onset, manifest for 30 seconds to 3 minutes and then resolve on its own.  Could this disease by a neurological disease?

It was then that I decided to do my own clinical trials.  I started treating these cats with phenobarbital which was the gold standard for treating cats with seizures due to epilepsy.  It worked.  The cats who had this disease, became clinically normal while on the anti-seizure mediation.  Seemed like I had some proof that it was neurological (brain) and not skin.  I passed on my information to my colleagues and they laughed it off, but that is the typical response if you are a general practitioner and not a researcher.  They said the same thing when I told them I discovered that systemic lupus actually does happen in cats.

In time, my idea of FHS being a brain imbalance has caught on by some researchers.  Research done at Cornell Vet School suggests that it is a brain disorder and that treating it as a seizure problem is the best treatment available.

As a holistic vet, my job is not to stop at pinpointing where the symptoms are originating, but to dig deep enough and hopefully, connect the dots to find out what is actually causing the brain problem.  Words like idiopathic and syndrome don’t cut it for me.

I started thinking about all of the potential factors that could contribute to this brain imbalance and there are some definite possibilities, but one seems to stand out as the most likely cause.  Rabies vaccination.

Rabies vaccination is given on a regular basis to almost all pets as it is required by state laws.  If we take a look at rabies vaccine we see two possibilities that contribute to the brain imbalance that could trigger these particular symptoms.  Most rabies vaccine given to pets has Thimerosal in it as a preservative.  Very few vets use Thimerosal-free vaccine as they have not been told of the potential harmful effects of Thimerosal.

Thimerosal has 46% mercury inside its chemical compound, so every time your pet gets vaccinated for rabies (that includes Thimerosal), it gets a blast of mercury.  Mercury in the body does not get excreted, so it finds a place to stay and if the body gets more, then it has an accumulative effect.  The more rabies vaccination, the more accumulated mercury in the system.  

If we look at the typical symptoms of mercury intoxication, we see some interesting things.  Symptoms include brain dysfunction manifesting in several potential clinical presentations and one of them is described as a twitching sensation along the spine that resembles insects under the skin.  This sounds exactly like the symptoms of our twitching cat.  This is certainly worth consideration.  

Rabies vaccine is also a vaccine that is made of modified viruses and on occasion a pet will have a vaccinosis reaction where the patient starts to exhibit symptoms similar to rabies:  particularly aggression.  Could this be a factor as well?

There are other potential variables that could contribute to FHS and its symptoms.  Leaky gut caused by inappropriate diet causes inefficient utilization of proteins and their utilization of amino acids.  This improper processing often leads to production of chemicals that pass into the blood stream and cross the blood brain barrier affecting brain function.  We know that some neurological symptoms, cognitive dysfunction, training incapabilities, etc have been linked to this abnormal chemical buildup.  Repairing damaged gut will often resolve this problem.  

Other possible factors would have to include chemical pesticides for fleas and ticks, exposure to toxic chemicals on lawns and other toxic factors.

I have had good luck treating these pets using heavy metal chelation, detoxification and Chinese herbs to restore normal balance.  Until conventional medicine decides to find the actual cause of this disease, I would recommend that you find a good holistic vet that will help you.  In the meantime, if you have to give rabies vaccine, make sure that it is a Thimerosal-free vaccine.  You must ask the vet and not assume that they have the one you need.