19203 Aurora Ave N
Shoreline, WA 98133
(206) 546-1243


5506 Pacific Avenue
Tacoma, WA 98408
(253) 471-9200

Restoring Health & Happiness to Senior Cats Since 1992

Restoring Health & Happiness to Senior Cats Since 1992


What is the best treatment option for Feline Hyperthyroidism?

Radioiodine treament is the safest and most effective therapy for Feline Hyperthyroidism available. The treatment involves a one-time, subcutaneous injection, nothing invasive. General anesthesia is not required for therapy hence eliminating a major risk factor for the geriatric cat.

What Is The Cost of Radioiodine Treatment?

The total cost of the treatment is $1345 to $1745 which includes a consultation/physical examination ($95) by one of our veterinarians, and radioiodine treatment and hospitalization ($1000-$1400). The range in treatment fees is based on the dosage of I-131 that your cat requires. Your cat's dose can only be determined by examining the cat in person.

0.5 to 5.0 mCi.................$1250.00  (80% of cats we treat receive less than 5.0 mCi.)

5.01 to 10 mCi.................$1450.00

10.01 to 15 mCi...............$1650.00  (The rare cat with a markely elevated T4 (>25 ug/dl) )

These fees are due when your cat is left for treatment. We accept all major credit cards, Care Credit, and cash. Checks are not accepted.

How do I schedule an appointment?

We reserve a spot for the treatment on the same day as the consultation with Dr. Vaughan to reduce car trips for your cat. However, if you prefer to schedule the consultation only, we are happy to accomodate that request. Appointments are offered on Mondays and Thursdays in Shoreline and, in Tacoma, three Tuesdays each month. Our physical exam and review of your cats' medical records help determine whether your cat is a good candidate for 131I treatment, and if so, what dose will be best.

If your cat is arriving by air, we will want him/her to arrive no later than the day before treatment. We will give you the phone number of a courier service which you can call and make arrangements to transport your cat to and from the airport. An additional fee will be charged by the courier company.

Why Does My Cat Need To Be Scheduled at a Specific Location (Shoreline vs. Tacoma) ?

The Shoreline office, our original location, has more staff and longer hours, therefore will examine and treat all cats that fall into the following categories:

  • Cats that are considered "medically fragile", i.e. have additional illnesses effecting the heart, the kidneys, etc. which is more likely in senior cats.
  • Feral cats or cats requiring sedation to be examined
  • Cats with a T4(thyroid hormone) level of 15 or higher

Our Tacoma office was established to treat cats that require low doses of radioiodine, i.e. a T4 level of less than 14.

What lab work is needed prior to treatment?

The following labs need to be less than 6 weeks old:

  • CBC
  • Chemistry Screen with Quantified T4
  • Urinalysis
  • Blood pressure (recommended but not required)

(if your cat is currently on Methimazole/Felimazole or y/d, please call before having updated lab work done.)

Is it possible that my cat is not a good candidate for radioiodine treatment?

To be candidates for radioactive iodine therapy, we request that all cats have screening laboratory work (CBC, Chemistry profile and urinalysis) and a blood pressure when possible performed by the referring veterinarian within one month of the treatment date. Cats with questionable kidney function may need testing within 1 week of the procedure. Cats with significant heart disease should be accompanied by the appropriate diagnostics. We will contact your veterinarian to request the medical records.

If your cat has significant kidney failure, advanced heart failure or a malignant cancer, we can resolve the hyperthyroidism, but may be unable to make your cat better by treating the hyperthyroidism alone and you may not want to treat your cat due to the poor prognosis of the other disease processes.

Age is not a determining factor.  We have treated multiple cats that were 21 years old.  They were in good physical shape and did very well.

How long will my cat be in the hospital?

Once admitted for therapy, your cat cannot be discharged until its radiation exposure rate is at or below the level determined by the state. Cats will remain in the hospital as little as one night and as long as 10 nights. The average stay is 2-3 nights, but after the consultation when your cat’s dose has been determined we will give you an estimate based on your cat’s treatment. Cats having high thyroid levels or very large thyroid tumors usually require larger iodine doses and therefore may need to remain hospitalized longer.

My cat does not do well away from home. What do you do to keep cats comfortable?

As a feline-only facility, we are accustomed to catering to feline needs.

  • Since we see only cats, your cat will not be able to smell or see dogs, a common source of feline stress.
  • Your cat is being cared for by doctors and staff that have specifically chosen to work with cats.
  • Our hospital compartments are individually ventilated. All expired air is removed from the building. This decreases odors and stress pheromones as well as decreasing the incidence of infectious respiratory diseases.
  • The nuclear ward is separate from the main hospital making it a "quiet zone".
  • For especially nervous cats, we can provide a privacy curtain and/or a hidingn box.  
  • We can also use Feliway, a feline pheromone, which has a calming affect for most cats.
  • Fresh food and water are available at all times. Please inform us of any likes or dislikes or special dietary needs that your cat may have, so we can make their stay as comfortable as possible.
  • We also offer safe anti-anxiety medications for your cat daily.

May I visit my cat while in the hospital?

No; ,state regulations do not permit owners in the radiation ward. Toys or blankets from home are also not permitted because they would become contaminated and create more radioactive waste to be disposed of.

How will I find out about my cat's condition during hospitalization?

We will call you daily between 9:00 a.m. and 10:00 a.m. during your cats’ hospitalization to let you know how your cat is doing, how they are eating, and whether or not they are able to be released that day. 

When my cat is ready to come home, what do I have to do?

During the initial consultation, Dr. Vaughan will provide you with a timeline specifically tailored to your cat.   Always provide a pet carrier for your cats' safety and in case of bathroom accident. If your cat will be traveling by plane, Dr. Vaughan will inform you at the initial exam when the anticipated discharge day will be.You will need to arrange the courier and the return flight. Charges for airfare and courier service will be taken care of by you.

If Your Cat Is On Thyriod Medication:

Do I need to stop the antithyroid medications (Tapazole/Methimazole/Felimazole) prior to treatment?

Yes. They should be discontinued approximately 1 week before treatment. Exceptions can be made if your cat has serious cardiac disease. If this is a factor, you will be instructed by your veterinarian or by Dr. Vaughan. If your cat can tolerate being without these medications for longer, then discontinue them even sooner. The antithyroid medications may decrease uptake by the abnormal thyroid tissue, and therefore will decrease its effectiveness. So, the longer they can be off these medications without compromising their health the better.

Are there any medications or supplements I should avoid prior to therapy?

As previously mentioned, Tapazole(Methimazole/Felimazole) should be stopped 7 days prior to treatment.

Any supplements containing iodine, kelp (high in iodine), or are high in calcium or magnesium should be discontinued one week prior to therapy.

We have had some treatment failures in cats on holistic/herbal nutritional supplements, therefore we ask that supplements and  additives not be given for 1 week prior to, and after treatment. Continue all prescriptions i.e. antibiotics, heart medication and/or flea products as directed by your veterinarian.


What Precautions Do I Need To Take After Treatment?

For the first two weeks upon returning home, following these guidelines is advised to decrease your lifetime exposure to radiation. There are NO health risks to you, your family, or to your other pets.

  1. Keep your cat indoors or under direct supervision or a leash if outside. The concern is that a roaming cat will come in contact with other people. They will not contaminate the earth with radioactive waste.
  2. We advise close contact (closer than 1 foot) should be limited to one hour per day. The dose you are exposed to is extremely low and will have no medical consequences. We are attempting to minimize your lifetime cumulative exposure.
  3. There is no risk for other pets. Your cat can share the litter box with other cats, can play, and sleep with other pets as usual.
  4. For this two week period the litter must either be scooped daily and stored.

    TO STORE THE LITTER:  Get a large bucket (5 gallon paint bucket) and line it with a trash liner. Scoop urine and feces into the bucket daily. At the end of the two weeks, the entire contents of the litter box should be emptied into the bucket. Put lid on bucket and store in garage, basement, or utility room for 80 days. DO NOT dispose of the litter prior to 80 days; garbage dumps have radiation detectors and will charge you a hefty fine if radiation is detected.

  5. Wash your hands carefully after handling your cat; litterpan and food dishes.
  6. Do not allow children or pregnant women to have contact with your cat.
  7. To minimize your lifetime cumulative exposure, we advise you against sleeping with your cat.

These precautions seem like my cat is hazardous to me.  How dangerous is it?

The amount of radiation remaining in your cat is extremely low. A hyperthyroid person having radioiodine treatment typically receives up to up ten times the dose your cat will receive, goes home the same day treatment was given, and contact restrictions are limited to a day or two.  The amount of radiation you might receive from exposure to your cat after they have been treated would be equivalent to the radiation received when you fly(atmospheric radiation) round trip across the country.

How quickly will this treatment cure my cat's hyperthyroidism?

The short answer: Within 1 to 3 months.

The long answer:  At 1 and 3 months after the treatment, an exam and a blood test for thyroid and kidney function should be done by your veterinarian.  The 1 month level thyroid may be slightly high, low or normal. During this first month your cat generally shows no side effects as it returns to its original prehyperthyroid status, a very rare cat may be mildly sluggish, sleep more and eat less.  Excessive shedding may also occur (rarely).  These signs are all related to correction of the thyroid hormone imbalance.  The 3 month T4 test should no longer be elevated.  Any signs persisting after the T4 is normal are most likely due to other medical problems that need to be identified and treated by your veterinarian.




I wanted to drop you and everyone at FHTC a note to let you know that Byron (the PAWS’ kitty FHTC treated pro bono earlier this year) was adopted last month! Even better, he was adopted with another senior, all-black kitty we had in care.... read more »

Seattle, WA

As a member of an animal rescue organization on Vashon Island (VIPP), as well as being a chronic cat owner, I've had many opportunities to visit the Feline Hyperthyroid Treatment Center. Over the past 30+ years, I've taken scores of cats to Shoreline for definitive... read more »

Vashon Island Pet Protectors
Vashon Island, WA

My cat was diagnosed as hyperthyroid when she was 10.  We had her treated as soon as she was diagnosed and I was glad it was found early. I didn’t really give the thyroid medication much consideration because she was difficult to pill and knowing... read more »

Lynnwood, WA

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