What is feline hyperthyroidism and I-131 therapy?
General Information about Feline Hyperthyroidism and I-131 Therapy in Cats Cat hyperthyroidism is a commonly diagnosed endocrine pathology in older cats. It is caused by a tumor that produces too much feline thyroid hormone. Feline Hyperthyroidism may be treated with medicine, surgery, or radioactive iodine:
How is iodine used to treat hyperthyroidism in cats?
Treatment of cats for feline hyperthyroidism with Radioactive Iodine (I-131) is the preferred method of therapy (and well as in humans). It is as easy as one injection just under the skin, much like a routine feline vaccine. I-131 is safe and effective.
How deep does radioactive iodine go in a cat?
I-131 is a radioactive form of iodine, which the diseased thyroid takes up. Penetration is only 1-2 mm deep, which spares the underlying healthy thyroid cells. Your veterinarian will refer your cat to a specialist veterinary centre for treatment. Are all cats good candidates for radioactive iodine treatment?
How much iodine do I give my Cat for skin cancer?
One injection under your cat's skin is all that is needed! The cost of radioactive iodine therapy is similar to the other forms of therapy, and is often less expensive when compared to long term medical therapy or the higher probability of a required second surgery.
How many microcuries per gram for Graves disease?
Most clinicians use a dosage of 55 to 80 microcuries per gram for Graves' disease. For very enlarged glands and severely hyperthyroid patients, larger doses of 160 to 200 microcuries per gram are given.
Why should I be hydrated before and after iodide?
Patients should be adequately hydrated before and after administration of sodium iodide-I-131 to assure rapid urinary elimination of the iodide that is not absorbed by the thyroid.
Is sodium iodide used for hyperthyroidism?
Sodium iodide-I-131 is not usually used for treatment of hyperthyroidism in patients under 30 years of age.#N#Care should be taken to minimize radiation exposure to the patient and occupational workers.#N#The uptake of radioiodide will be affected by recent intake of stable iodine in any form, or by use of thyroid, antithyroid, and certain other drugs. The patients should be questioned carefully regarding previous medication and procedures involving radiographic contrast media.#N#Radioiodide therapy in women of childbearing age should only be performed when appropriate contraceptive measures have been taken or when pregnancy testing is negative.#N#Radiopharmaceuticals should be used only by physicians who are qualified by training and experience in the safe handling of radionuclides.#N#Patients should be adequately hydrated before and after administration of sodium iodide-I-131 to assure rapid urinary elimination of the iodide that is not absorbed by the thyroid.
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.
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.
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.
Why do cats become hyperthyroid?
In most cats, hyperthyroidism is caused when a portion of the thyroid gland becomes overly active, loses its normal regulation, and secretes excessive amounts of thyroid hormone. However, in a small percentage of cats, hyperthyroidism is caused by thyroid cancer.
How does Iodine 131 therapy treat hyperthyroidism?
Iodine is an element normally taken up in large amounts by the thyroid gland, even more so in cats that are hyperthyroid. When a radioactive form of iodine is given to hyperthyroid cats, the radiation destroys a portion of the thyroid gland.
Which cats can be treated with radioiodine (Iodine 131)?
Radioiodine is an appropriate treatment for cats with hyperthyroidism that are in a stable medical condition. Because these cats are emitting radiation during this treatment, only basic care (feeding, cage cleaning) is provided during the isolation period to prevent excessive exposure to personnel.
How long will my cat be in isolation?
The length of isolation depends on how quickly the levels of radiation emitted from your cat decline. For most cats treated at the University of Tennessee, this period lasts approximately 6 to 10 days, making the total stay in the hospital approximately 8 to 14 days.
What is involved in a pre-treatment evaluation?
Blood and urine tests and chest x-rays are made to evaluate the overall medical condition of your cat. Many of the tests previously performed by your veterinarian may be repeated in order to have the most up to date information at the time of treatment. A nuclear medicine thyroid scan will be performed to get an image of your cat’s thyroid gland.
Are there major side effects of radioiodine treatment?
All the noticeable effects of radioiodine treatment are good ones, with a few exceptions. Most cats return to normal thyroid function within days of treatment, many being normal by the time of release from the hospital.
Do I need to bring my cat back to UTCVM for follow-up testing?
No, the follow-up blood tests to check thyroid hormone levels can be done by your primary veterinarian.
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.
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.
What is the treatment for iodine in cats?
Radioactive Iodine Treatment (I-131) For Cats. Radioactive iodine (radioiodine or I-131) is used in the treatment of hyperthyroidism which is the most common endocrine (hormonal) disorder to affect cats. It is estimated that 10% of cats over ten of cats over the age of ten will develop the disease. The disease is caused by a benign, ...
What is the I-131 in cats?
I-131 is a radioactive form of iodine, which the diseased thyroid takes up . Penetration is only 1-2 mm deep, which spares the underlying healthy thyroid cells. Your veterinarian will refer your cat to a specialist veterinary centre for treatment.
How long before radioactive iodine treatment can cats stop methimazole?
Stop medications and/or special diets: The cat will stop methimazole (Tapazole) or carbimazole or Hills Y/D (a prescription diet low in iodine) 7-10 days before radioactive iodine treatment.
How does radioactive treatment work for cats?
How does radioactive treatment work? The thyroid gland uses iodine-which is in many types of food to make the thyroid hormones. Cats with hyperthyroidism have abnormal and hyperactive thyroid tissue as well as atrophied healthy thyroid tissue. I-131 is a radioactive form of iodine, which the diseased thyroid takes up.
What is cardiac thyrotoxicosis in cats?
Collectively called cardiac thyrotoxicosis. These are late manifestations of hyperthyroidism which highlight the importance of early diagnosis and bi-annual health checks in cats over the age of 7. High blood pressure (hypertension) is another common side effect of hyperthyroidism in cats.
How to treat hyperthyroidism in cats?
There are several treatment options for cats with hyperthyroidism which include: Prescription diet. Hills y/d is low in iodine, which is required by the thyroid gland to produce its hormones, low iodene=reduced hormone production. It can take a few weeks for this food to take effect. Medications.
How long is a cat in isolation?
The cat will be in isolation for 3-8 days. 95% of the radioactive iodine is excreted via the cat’s urine, with lesser amounts through the feces. Exposure to radioactive urine poses risks to veterinary staff and caregivers; therefore careful removal of urine is necessary at an approved facility.
What is the I-131 in cats?
General Information about Feline Hyperthyroidism and I-131 Therapy in Cats. Cat hyperthyroidism is a commonly diagnosed endocrine pathology in older cats. It is caused by a tumor that produces too much feline thyroid hormone. The disease is usually fatal if left untreated. Feline Hyperthyroidism may be treated with medicine, surgery, ...
Does thyro cat damage other tissue?
Does not damage other tissue or organs, including the parathyroid glands. Does not have harmful side effects. Returns thyroid function to normal usually within one month. Is cost effective. Thyro-Cat is an approved specialty facility with State Department of Health and Nuclear Regulatory Commission for use of I-131.
Can Iodine be used for hyperthyroidism in cats?
Surgery may not be effective in removing all of the affected thyroid tissue causing feline hyperthyroidism. Radioactive Iodine (I-131) therapy for feline hyperthyroidism is very effective, has few side effects, is a one-time treatment in over 95% of cats with hyperthyroidism, and does not require administration of pills or anesthesia.
Can cats take tapazole?
The disease is usually fatal if left untreated. Medical therapy for feline hyperthyroidism (methimazole - Tapazole®) is required daily, is a life-long treatment, and does not cure the cat's hyperthyroid condition. The difficulties associated with giving pills to cats often causes stress to both the animal and owner.
Can Iodine 131 be used on cats?
The I-131 hyperthyroid cat treatment is absorbed quickly into the cat's bloodstream and the diseased thyroid tissue. Once in the thyroid, it destroys the overactive portions of the thyroid gland. Radioactive Iodine I-131 feline hyperthyroidism treatment has the following advantages over medical and surgical treatments for feline hyperthyroidism:
Is I-131 safe for cats?
It is as easy as one injection just under the skin, much like a routine feline vaccine. I-131 is safe and effective.
Is radioactive iodine therapy expensive?
The cost of radioactive iodine therapy is similar to the other forms of therapy, and is often less expensive when compared to long term medical therapy or the higher probability of a required second surgery. Prior to making a final decision relative to initiating the I-131 hyperthyroidism therapy, all cats are screened closely for the presence ...
Radioiodine Procedures Pre-Referral Data
Procedure
- 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. It will also evaluate for the possibility of ectopic thyroid tissue. The scintigraphic study is usually d…
Post-Treatment Procedures
- At the time of release, the radiologist will meet with the owner and explain the post-treatment procedures. For the first two weeks following treatment: 1. Limit close contact (holding close to your own neck, sleeping next to) with your cat to a maximum of 30 minutes per day per person. 2. Keep your cat indoors. Scoop urine and fecal clumps from th...
Follow-Up with Referring Veterinarian
- 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. Follow-up blood work and T4 levels at 1, 3, 6, and 12 months are reco…