Radioactive Iodine Therapy – I-131 for Cats Veterinary Specialty Center provides iodine-131 treatment (I-131) for cats suffering from hyperthyroidism and thyroid carcinomas as an alternative to thyroid gland surgery. Radioiodine therapy is the least invasive, safest and most effective way to treat hyperthyroidism in cats.
What is the I-131 protocol for hyperthyroidism in cats?
Our protocol includes an imaging study of the thyroid prior to the I-131 therapy. Not only will the scintigraphic study confirm the diagnosis of hyperthyroidism in cats that do not have a palpable thyroid nodule, but it will also identify a relapse of hyperthyroidism following a thyroidectomy.
What should I do if my cat has I-131 radiation therapy?
A detailed post-treatment instruction handout is signed by the pet owner prior to patient release from radiation isolation. Feline I-131 patients should be transported home in a cat carrier and handled with latex gloves. A waste receptacle will be provided at the time of discharge along with a detailed post-I-131 patient care instruction sheet.
What happens if a cat gets I-131 twice?
Cats that still have elevated thyroid levels after I-131 treatment can be safely treated a second time if the thyroid levels remain high at least six months after the first injection. A very small percentage of cats may become permanently hypothyroid after I-131 treatment and will need to be on a thyroid supplement lifelong.
Is radioiodine the only treatment for hyperthyroidism in cats?
Leaves many cats still needing I-131 therapy, even after undergoing one or more surgeries. As you can see, Radioiodine therapy is the clear treatment of choice and the only consistent cure for Feline Hyperthyroidism.
How is I-131 administered to cats?
I-131 is administered to hyperthyroid cats by a subcutaneous injection. Cats treated with I-131 need to be hospitalized for 2-7 days following the injection. This is when they are the most radioactive.
Is radioactive iodine treatment painful for cats?
There are virtually no side effects, and there is no pain associated with 131I treatment. The delivery of iodine is targeted to the overactive thyroid gland(s), the cat does not experience any radiation side effects at the normal therapy doses used to treat hyperthyroidism.
How long does it take for I-131 to work in cats?
Most cats respond to treatment within weeks, although some take up to 6 months to gain the full benefit.
What happens after radioactive iodine treatment for cats?
Your cat will not experience nausea, hair loss, lethargy, or decreased appetite due to his procedure. However, following treatment, some cats may experience a short period of readjustment as the thyroid levels return to normal. This may include slight fluctuations in appetite and energy levels.
Can I touch my cat after radioactive iodine treatment?
Your cat may be slightly woozy when you pick them up. For the first two weeks after I-131: Keep your cat indoors or supervised when outside to prevent contact with other people. Limit close contact (closer than 1 foot) to one hour per day.
How long can a cat live after radioactive iodine treatment?
“Studies have shown that cats treated with I-131 live longer than those treated with pills,” added Mosenco, citing a study where I-131-treated cats lived an average of four to five years following treatment, versus an average of only two years for cats on medication.
Can I be around my pets after radioactive iodine treatment?
It is safe to be around your cats after you are treated with radioiodine therapy because even if they are in your lap, the exposure is low. People do sweat out the radioiodine, but if you wash your hands regularly, that is very effective in washing away the small amount of contamination on your hands.
How much does I-131 treatment cost cat?
The cost for radio iodine therapy is generally a total fee of $1500- $1550, depending on the I131 dosage required for your cat's treatment. This includes the radio iodine itself, the cost of hospitalization, food, litter, and monitoring.
How Long Can cats live with an overactive thyroid?
If effectively managed, cats with hyperthyroidism can live for many years with a very good quality of life. If untreated, this disease will cause uncontrolled weight loss, severe heart disease and eventually death.
How long to stay away from pets after radioactive iodine?
Here are some ways to minimize radiation risks to other people (and pets) after you have had RAI treatment: Stay at least six feet away from other people, including members of the public, family members, and co-workers, for three to 11 days.
How long do you have to be in isolation after radioactive iodine?
You are also required to self isolate for 7 days after your radioiodine treatment in order to minimise the risk of contracting COVID-19 whilst there is still a large amount of radioactivity in your body. A small proportion of people with COVID-19 may become very unwell and require admission to hospital.
Why do hyperthyroid cats meow so much?
Signs of anxiety in a cat – including pacing, yowling for no apparent reason, and restlessness – are a common symptom of feline hyperthyroidism. This is due to increased stimulation in the nervous system which is a common occurrence in cats with feline hyperthyroidism.
Does radioactive iodine harm my pets?
It is safe to be around your cats after you are treated with radioiodine therapy because even if they are in your lap, the exposure is low. People do sweat out the radioiodine, but if you wash your hands regularly, that is very effective in washing away the small amount of contamination on your hands.
How long to stay away from pets after radioactive iodine?
Here are some ways to minimize radiation risks to other people (and pets) after you have had RAI treatment: Stay at least six feet away from other people, including members of the public, family members, and co-workers, for three to 11 days.
How expensive is radioactive iodine treatment for cats?
$1500- $1550The cost for radio iodine therapy is generally a total fee of $1500- $1550, depending on the I131 dosage required for your cat's treatment. This includes the radio iodine itself, the cost of hospitalization, food, litter, and monitoring. This is comparable to the cost of surgical removal.
Can cats survive radiation?
The overwhelming majority of cats (>95%) are cured by a single therapy with only a small percentage of cats requiring additional radioiodine therapy (4%) or becoming persistently hypothyroid (1%). Occasionally cats will act like they may have a sore throat for a couple of days after the radioiodine therapy.
Why is radioiodine not concentrated in thyroid tissue?
Therefore, the radioiodine is concentrated by the hyperactive, abnormal thyroid tissue. Because the normal thyroid tissue becomes atrophied (decreased in size and ability to function) in the hyperthyroid patient , the normal thyroid tissue itself should not concentrate the radioiodine.
Where to administer radioactive iodine?
The protocol for administering radioactive iodine at the University of Minnesota Veterinary Medical Center is by the subcutaneous route (under the skin). The radioactive iodine is administered as a single injection under the skin in the region of the inner thigh. Because of the nature of the injection, we generally will administer a small amount ...
Why do cats stay in the hospital longer with kidney disease?
Due to the removal of iodine through the kidneys, cats with preexisting kidney disease may have to stay longer because the radioiodine may not be removed from the body as quickly. The patient will be monitored at regular intervals to determine when they are able to be released.
What is the most common hormonal disease in cats?
Hyperthyroidism may be the single most commonly diagnosed hormonal disease in cats next to diabetes. It is generally a disease of older cats with an average age around 9-10+ years, but can be seen in cats as young as 5 years of age. In most cases, the disease is caused by a growth of abnormal, non-cancerous cells which secrete thyroid hormones in ...
How do you know if your cat has hyperthyroidism?
If left untreated, a hyperthyroid cat can exhibit many, if not all, of the following signs: extreme weight loss, excessive appetite in most cases, but decreased appetite in some, muscle weakness, heart disease (in crease in the size of the heart, increased rate, changes in heart rhythm, cardiac arrest), intolerance to stress, and eventually death.
When can a patient be released from the hospital?
The patient can be released from the hospital once the exposure rate from the radioactivity in the body reaches a level that is deemed to be safe to the general public (i.e.: owners), which has been established by the University and the Minnesota Department of Health.
Can you bring in a blanket for a cat?
It is possible for owners to bring in something familiar from home for their cats (i.e.: blanket, shirt, etc. with their scent on it), with the understanding that it will not be returned after the stay because of radiation safety considerations.
When will cats be discharged from ISU?
This means that most cats will be discharged from the hospital the following Monday or Tuesday after I-131 treatment. Clients may not visit the pet prior to discharge, but will be updated daily on the health status of their pet by ISU Small Animal Internal Medicine.
What is involved in the initial screening process?
What is involved in the initial screening process?#N#The initial screening process performed by ISU Small Animal Internal Medicine includes: thorough physical exam, complete blood count and serum chemistry, total T4 value, and routine urinalysis. A urine protein:creatinine ratio is performed when proteinuria is identified. An SDMA test is performed if renal dysfunction is suspected. A free T4 may be run to confirm the diagnosis of hyperthyroidism if the total T4 is only marginally elevated or is within the high end of the normal range. The remainder of the screening process may include: survey thoracic radiographs, indirect blood pressure (usually via Doppler manometry) and a baseline electrocardiogram. Further cardiac evaluation (echocardiography) is not performed by the ISU Cardiology service, unless there is suspicion or evidence of cardiac disease determined during this initial screening process.
How long do cats have to be off methimazole?
It is required that cats be off methimazole a minimum of 7 days prior to referral (10-14 days preferred). Cats that are on Hills y/d food should be transitioned back to their regular diet prior to making an appointment for I-131 evaluation.
Is an echocardiogram performed by ISU?
Further cardiac evaluation (echocardiography) is not performed by the ISU Cardiology service, unless there is suspicion or evidence of cardiac disease determined during this initial screening process.
Can I-131 be used for hyperthyroidism?
If the total GFR is below this number, medical therapy for hyperthyroidism may be recommended, although I-131 treatment may still be an option in specific patients. Both diagnostic nuclear scans (thyroid scintigraphy and GFR) are currently performed on Wednesdays.
How is hyperthyroidism diagnosed?
Hyperthyroidism is diagnosed based on a combination of history, physical exam findings and an elevated thyroid level. Most cats with hyperthyroidism have a palpable thyroid nodule.
What are treatment options for hyperthyroidism?
Treatment options include methimazole, radioactive iodine (I131) and surgery. Surgery is rarely recommended unless a malignant thyroid tumor is suspected.
How does I131 work?
The thyroid gland is the only tissue in the body that concentrates iodine. The gland cannot differentiate between normal iodine consumed in food and radioactive iodine (I131). Radioactive iodine is given as a single SQ injection. After the injection, the radioiodine is concentrated in the hyperactive abnormal thyroid tissue thus destroying it.
About our program
If you are interested in radioactive iodine therapy for your cat, we ask that you schedule a consult to go over the treatment with any SAGE internal medicine specialist. At this appointment, your cat will be evaluated for any other problems and different treatment options will be discussed.
I131 treatment
We will admit cats on Tuesdays and they will be treated that day. They will typically be released on Friday afternoon. While they are at SAGE, they will be fed twice daily and receive routine care such as litter change, water, cage clean-up. We also play videos and music during the day.
After I131 treatment
You will need to have limited contact with your cat for 2 weeks after treatment (ie limited time sitting on your lap and no sleeping with you). See the owner release instructions form for more details.
Monitoring post I131 treatment
Kidney values and a T4 should be measured 1 month and 3 months after treatment. This helps monitor for any kidney disease which could be “unmasked” once the thyroid is normalized. Some cats will have a period of subclinical hypothyroidism where the T4 is low and normally does not require therapy. This typically resolves within 3 months.
What is iodine 131 for cats?
Veterinary Specialty Center provides iodine-131 treatment (I-131) for cats suffering from hyperthyroidism and thyroid carcinomas as an alternative to thyroid gland surgery. Radioiodine therapy is the least invasive, safest and most effective way to treat hyperthyroidism in cats.
How long after I-131 can I treat my cat?
Cats that still have elevated thyroid levels after I-131 treatment can be safely treated a second time if the thyroid levels remain high at least six months after the first injection.
How long does it take for a cat to get a thyroid shot?
Normal thyroid levels are usually reached between one and three months (sometimes up to five months) post-treatment. More than 95% of cats will be cured by a single injection. The remaining small percentage of cats can be treated a second time safely if the thyroid levels remain high six months after the injection.
How long does an I-131 stay in a hospital?
Due to the radioactive nature of the I-131, the patient is obligated to remain within the state-approved shielded facility at all times during the established days of hospitalization (approximately five days). Safety regulations do not allow any visitors in the treatment/housing area.
Do radiologist monitor patients?
Safety regulations do not allow any visitors in the treatment/housing area. The radiologist will monitor each patient every day. Owners will be updated on a daily basis on the status of their pet by a technician. The referring veterinarian will receive a notification once the patient is discharged from our hospital.
Can cats be treated with I-131?
Cats with renal failure or other chronic illnesses may not be the best candidates for I-131. If I-131 treatment is absolutely necessary, these patients should be stabilized as much as possible prior to treatment. In this way, we hope to avoid complications during hospitalization following the I-131 treatment.
Why is thyroid imaging important?
Thyroid imaging is the best way to assess tumor functionality and determine the size of the thyroid which will help planning the treatment . This is especially important because conventional doses I-131 treatment is not effective for thyroid carcinomas.
What is the most common endocrine disease in cats?
Hyperthyroidism is the most common endocrine disease in the cat and affects about 10% of senior and geriatric cats. The majority of hyperthyroid cats (~95%) have benign thyroid adenomatous hyperplasia (or adenoma) involving one or both thyroid lobes at the time of diagnosis. Thyroid carcinoma (cancer) occurs in about 2-5% of the newly diagnosed cases. However, the incidence of thyroid carcinoma in cats treated with methimazole that are referred for I-131 therapy because of refractoriness to higher doses of methimazole, has dramatically increased.