Secondary Problems If you suspect your cat might be experiencing some of these symptoms, the next step is visiting your veterinarian for a blood test to check your cats thyroid hormone levels. Montreal. Because the radioactive iodine used (known as iodine 131) may expose those around you to the effects of radiation (and theoretically negatively affect their thyroid glands), you will be given guidelines on how to prevent such exposure. Most cats with hyperthyroidism have elevated levels of the thyroid hormone T4 in their bloodstream, but a small percentage of cats with hyperthyroidism have T4 levels within the normal range. Thyroid hormone regulates the metabolic rate of an animal. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. Cats with hyperthyroidism exhibit symptoms that are similar to those of humans with the disease: weight loss, increased appetite, excessive . Employees of facilities that utilize radioactive materials may be categorized as "radiation workers" depending on their role. Radioactive iodine therapy is becoming the treatment of choice for felines with hyperthyroidism. Always check with your veterinarian before changing your pets diet, medication, or physical activity routines. This can best be done by monitoring your cats body condition, muscle condition, and weight. The thyroid takes up the radioactive iodine, which destroys cells in the thyroid. The more common symptoms are an increase in thirst, urination, and appetite, as well as weight loss. The majority of cats treated with radioactive iodine have normal hormone levels within one to two weeks of treatment. The outcomes following most hyperthyroid therapies are usually excellent, and most cats have a very good chance of returning to a normal state of health. Hyperthyroidism, or an overactive thyroid, is a common disease of older cats. There are fundamental differences between a continuous dose over a year (background radiation) and a dose that occurs over a few seconds like in CT, but these are helpful comparisons. If these tests are not diagnostic, athyroid scan (thyroid scintigraphy)can be performed at a veterinary referral center, or the TT4 can be measured again in a few weeks. Hence for a transient period following radioiodine therapy, the patient's urine contains excreted radioiodine which will emit beta particles as it continues to decay. However, because your cat will be radioactive for several days after receiving the shot, precautions must be taken during and after the treatment. Set up your myVCA account today. In cases where radioactive iodine therapy is not successful, the treatment can be repeated. Answer posted on 30 March 2019. Cats treated with radioactive iodine for their hyperthyroidism have several risks unrelated to the radioiodine therapy itself. Title 10, Code of Federal Regulations What happens after radioactive iodine treatment for cats? As in the case of heart disease, after the hyperthyroidism has been successfully treated, high blood pressure will often resolve, and permanent treatment for it may not be required. Already have a myVCA account? Interestingly, when higher doses are given, like those received by the patient treated for hyperthyroidism or thyroid cancer, then the injury to the cells is terminal and hence the cells do not survive to go on to become malignant. TheCatSite.com is a community of cat lovers dedicated to quality cat care and cat welfare. People may take RAI . 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.Dec 19, 2016. (At my facility we treat people but many of the concepts are the same, it is just that patient compliance is easier to obtain with people.) Medication and radioactive iodine therapy are just as effective at treating hyperthyroidism in cats as surgery and are less invasive, so surgical treatment is rarely chosen for treating this condition. Both cardiomyopathy and hypertension are potentially reversible with appropriate treatment of the disease. The dose of radioactive iodine is taken orally. The first step is determining the blood level of one of the thyroid hormones calledtotal thyroxine (TT4). This can best be done by monitoring your cat's body condition, muscle condition, and weight. Radioactive iodine therapy offers a cure through a simple injection that returns thyroid function to normal levels. Medication If your cat does not have elevated T4 levels but your veterinarian still suspects your cat has hyperthyroidism, additional tests may be recommended. Many organs are affected by hyperthyroidism, especially the heart. hypothyroidism was only treated if it was associated with clinical signs like excessive weight gain, lethargy, and skin problems. If the nearest facility is far away, there's the stress or travel for both you and Fluffy, as well as possible hotel and other travel expenses. The radioiodine (I-131) used to treat thyroid disease in people and animals emits both gamma rays and beta particles. Now that I know my cat has hyperthyroidism, what do I do? 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%). Mean baseline age was 12.7 3.0 years and mean baseline BMI SDS was 0.003 1.18 kg/m 2. Subpart D-Radiation Dose Limits for Individual Members of the Public This I131 injection accumulates in the abnormal thyroid tissue, and the radioactivity kills the abnormal tissue without harming other vital structures nearby. . To the best of our knowledge, answers are correct at the time they are posted. Luckily these risks will diminish in time following successful radioiodine therapy and a return to a persistently normal thyroid level. This cat is showing weight loss and poor coat - typical signs of hyperthyroidism. For some cats, a veterinary therapeutic diet low in iodine may be all thats required to control symptoms. The veterinarian's recommendations are to isolate my cat for at least two weeks. Because the thyroid needs iodine to produce hormones, the thyroid takes the radioiodine into the thyroid cells and the radiation destroys the overactive thyroid cells over time. Your cat can receive methimazole, a medication that inhibits thyroid hormone production. If both thyroid glands require removal, there is a risk of developing hypocalcemia (low blood calcium levels) after surgery. The three ways that we control exposures to external sources of radiation are time, distance, and shielding. Radioactive iodine therapy offers a cure through a simple injection that returns thyroid function to normal levels. Weigh the pros and cons of various treatments and discuss options with your vet. What about radioactive iodine treatment for children and teenagers? RAI is a form of radioactive nuclear medication that permanently destroys thyroid tissue. Radioactive iodine therapy is curative within three months of therapy in approximately 95 percent of all hyperthyroid cases. Treatment usually requires one or two weeks of hospitalization at a veterinary hospital licensed to administer radiation therapy. Many doctors recommend that women avoid becoming pregnant for 6 months to a year after treatment. Over ten years of clinical nutrition research revealed that by controlling dietary levels of iodine, the hyperthyroid cat's body would resume normal thyroid hormone production. Antithyroid medications are also available in a gel that can be applied to the skin. 2 The goal of RAI treatment is to restore euthyroidism while avoiding the development of hypothyroidism. This treatment is appropriate for cats with more surgical risk due to other health problems or who are exceptionally old. You may gain weight after you undergo radioactive iodine treatment. Radioactive iodine targets the thyroid tissue - as this is the only tissue in the body that uses significant quantities of iodine. The typical cat with hyperthyroidism is middle-aged or older; the average age of affected cats is approximately 12 years. One of the reasons the cat was held for four days was to allow for much of the radioactive 131I to be excreted in urine so that the amount of external radiation exposure is significantly reduced. You'll have to give him this drug twice daily for the rest of his life, which treats but doesn't cure the condition. This problem resolved rapidly after treatment. The good news is that virtually every client will already take steps to avoid this, even when radioactive iodine in their cat's urine is not the motivation. Pediatrics, 1998. When an injection of radioactive iodine is given, it destroys the abnormal thyroid tissue without endangering other organs. Radioactive iodine therapy. The risks of ingesting radioactive iodine and the risks of being around a patient that has been treated with radioactive iodine are very different. Radioactive-iodine therapy is becoming increasingly popular when dealing with hyperthyroidism in cats. Also, you might get some good ideas about what to feed him on Dr. Lisa Pierson's web site. All three have risks and benefits. Since platelets are essential for blood clotting, thrombocytopenia may lead to problems with excessive bleeding. Clients owning hyperthyroid cats undergoing radioiodine therapy are always considered members of the general public. Radioactive iodine (RAI) is a treatment method for hyperthyroidism and thyroid cancer. The prognosis for cats with hyperthyroidism is generally good with appropriate therapy. American Academy of Pediatrics. Purraise. It has to do with how important your thyroid is in regulating your metabolism and your weight. In more serious cases, surgical removal of the thyroid glands may be required. Objective: To investigate the long-term effects of continuous methimazole (MMI) therapy. JavaScript is disabled. This helps us offset the costs of running this site, so thank you for your support! Thyroidectomy (largely replaced by radioactive iodine . 122(6): p. 2444-61. Although the thyroid gland enlarges in hyperthyroidism, it is usually a benign or non-malignant change. However, once the underlying hyperthyroidism has been controlled, the cardiac changes will often improve or may even resolve completely. Their hyperthyroidism won't come back, and they don't need ongoing medication. The beta particles, which are much more potent forms of radiation, travel an average distance of less than 1 mm. The Disadvantages of Radioiodine Therapy Treatment for Cats, American Veterinary Medical Imaging: Feline Hyperthyroidism, Washington State University College of Veterinary Medicine: Radioactive Iodine Treatment of Hyperthyroid Cats, Washington State University College of Veterinary Medicine: Hyperthyroidism in the Cat, Cornell University College of Veterinary Medicine: Hyperthyroidism in Cats. Symptoms include weight loss, muscle wasting, increased appetite, increased thirst and urination, vomiting, unkempt appearance, and sometimes hyperactivity. The radioactive isotope, Iodine-131 ( 131 I), is administered as a one-off injection. With this therapy, you take radioactive iodine (radioiodine) by mouth. For example, some families cant medicate cats every day, so a more permanent solution such as radioactive iodine treatment or surgery may be best. A veterinarian who suspects a cat has a thyroid problem will conduct a physical examination and palpate the cats neck area to check for an enlarged thyroid gland (see Figure 2). The food isnotmedicated. The current Nuclear Regulatory Commission radiation dose limits for individual members of the public are listed below. The advantages of radioactive iodine therapy are that the procedure most often cures hyperthyroidism, has no serious side effects, and does not require anesthesia. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. If radioactive iodine therapy won't work for you and your cat, alternatives are available. If the disease involves both lobes of the thyroid gland, two surgeries may be required, depending on the surgeon's choice of procedures. It will take about a month for thyroid levels to return to normal in most cats. A small number of cats will remain hyperthyroid after treatment, if this is the case your cat will need . Even after treatment it may take a long time to reverse weight loss and muscle loss that occurred before your cat's diagnosis. The inaccurate repair of DNA is rare, but can cause a cell to act wildly or grow into a cancer. For this reason, some cats with hyperthyroidism may require additional treatment to control secondary heart disease. The routine stay in our radioactive iodine unit is currently 12 days. Radioactive iodine is an effective and safe treatment option for children and teenagers with an overactive thyroid gland, but will usually be given as a second-line treatment after a reasonably long course of antithyroid medication. All rights reserved. Risks unrelated to radioiodine therapy: Cats treated with radioactive iodine for their hyperthyroidism have several risks unrelated to the radioiodine therapy itself. Slater M.R., Komkov A., Robinson L.E., et al., Long-Term Follow-up of Hyperthyroid Cats Treated with Iodine-131. Radioactive iodine may also affect a woman's ovaries, and some women may have irregular periods for up to a year after treatment. . Research into this potential treatment option is ongoing. In cats, an underactive thyroid is extremely rare. The cell repairs itself with mistakes (rare). Dry, dull coat. Only certain facilities perform this procedure, which consists of giving your cat a shot of radioactive iodine, which gets rid of abnormal thyroid cells without harming normal ones. Hypertension develops due to the increased pumping pressure and elevated heart rate that occurs with hyperthyroidism. Medication typically. Note that the reference above excluding licensee's from considering "exposure to individuals administered radioactive material" in their compliance with the NRC regulartions does not apply to animals. (For example, for human patients we provide instructions such as "sleep in separate beds" and "stay at least 1 meter away from others as much as possible.") There are two types of radiation exposure that your vet is trying to minimizeexternal exposure from the radioactive material within the cat's body, and the radioactive materials in the cat's urine and other bodily fluids released by the cat that you may come into contact with and may end up being ingested or absorbed by you accidentally. This surgery requires general anesthesia, however, and there might be added risks if older cats have heart, kidney, or other problems that could cause complications. About 25% of cats with hyperthyroidism become hypertensive. J Am Vet Med Assoc, 2006. Milner R.J., Channell C.D., Levy J.K., et al., Survival Times for Cats with Hyperthyroidism Treated with Iodine 131, Methimazole, or Both: 167 Cases (1996-2003). When this occurs, a second test, usually afree T4 by equilibrium dialysis (FT4 by ED)or aT3 suppression test,is performed. Dr. Heinze is an employee of Mark Morris Institute and has provided professional serviceshas done consulting for Lafeber and WellPet, given sponsored talks for Nestl Purina PetCare and the Pet Food Institute, and provided professional services to Balance IT.com and Mark Morris Institute. These licenses establish the basis for the facilities compliance with federal regulations established by the United States Nuclear Regulatory Commission. However, because your cat will be radioactive for several days after receiving the shot, precautions must be taken during and after the treatment. You'll need to consider whether to have radioactive iodine (RAI) vs. other treatments for hyperthyroidism and Graves' disease (an immune system disorder that can cause hyperthyroidism). As to your question about "home-testing equipment" and "something else to monitor and determine (your) exposure," there really are no good options for that. Despite the extensive blood and urine tests, chest x-rays and physical exams that we require before radioiodine therapy, some of these conditions remain undiagnosed at the time of radioiodine therapy. There are several treatment options, and your veterinarian will determine the best choice for your cat. When an injection of radioactive iodine is given, it destroys the abnormal thyroid tissue without endangering other organs. Also, I wonder if there is home-testing equipment to track the household dispersal of the radioactive contaminants that he emits after his treatment and something else to monitor and determine my exposure to the 131I remnants. Risks from other illness. What is not taken up by the thyroid will be present in the cat's bodily fluids and will primarily be voided in the cat's urine (in those first four days at the vet hospital). (8,9) Replacement hormone products currently on the market, both synthetic and glandular, are not comparable to our own hormone, and in some people, never feel "right". Your cat may be hospitalized for one to two nights following surgery and should begin to eat and behave normally after returning home. This test can also help the doctor determine the cause of your hyperthyroidism and get other information about your thyroid tissue. After initial stabilisation with oral medications, a number of curative treatments are also available. Thyrotoxic cardiomyopathy may develop because the heart enlarges and thickens to meet the increased metabolic demands. It is important to remember that old age is not a disease. It is important to drink fluids after your treatment and for the next 2 days. Of 247 patients receiving RAI for GD, 157 (79.6% female) had complete data and were included in the analysis. He also can't sleep with you during that time, and the facility will inform you about special arrangements you'll have to make for disposing of his litter. What they are trying to prevent is the intake (ingestion, etc.) Cats afflicted with hyperthyroidism usually develop a variety of signs that may be subtle at first but that become more severe as the disease progresses. Despite the extensive blood and urine tests, chest x-rays and physical exams that we require before . Hence additional separation between the patient and children are unnecessary. But those instruments are quite expensive and are not readily available in stores. It is given one to three times daily and must be continued for the remainder of the pet's life. Hyperthyroidism & Liver Function in Cats, Intervals of Depo-Medrol Injections for Cats. Finally, thyroid hormone has a role in kidney function and blood flow that may result in either directly damaging the kidney or obscuring underlying kidney disease that your cat may already have. Having said that, the clients who own the cats we treat with radioiodine should make every effort to avoid ingesting any contents from the litter box. Elevated thyroid hormones stimulate an increased heart rate and a stronger contraction of the heart muscle, and can cause thickening of the left ventricle of the heart over time. Dietary restriction of iodine is, however, somewhat controversial because of concerns about the effects of long-term iodine restriction on overall health and the possibility that such a diet may actually backfire and worsen hyperthyroidism. He's radioactive, so it's not safe even for humans wearing protective clothing to spend too much time around him. Unfortunately, 131I has a rather high-energy gamma emission that is difficult to shield. ), family history (genetics) or radiation exposure. Cats are homed in our spacious, purpose-built radioactive iodine unit and cared for by our dedicated team of radioiodine nurses. Most cats with uncomplicated hyperthyroidism will live several years following treatment of hyperthyroidism, unless they develop another disease. Radioactive iodine therapy is the treatment of choice, however, because it destroys abnormal thyroid tissue without damaging the surrounding tissue, providing a more permanent form of treatment. . Several complications of hyperthyroidism can be significant, includinghypertension(high blood pressure) and a heart disease called thyrotoxic cardiomyopathy. Each treatment option has its advantages and disadvantages. 7. As youre on this website right now, we can assume that you love pets and likely have a special dog or cat (or many) in your life. Treating Hyperthyroidism in Cats. It has the advantage of being curative in most cases with no ongoing treatment. Aim: Analysis and follow up of body weight after radioiodine therapy (RITh) of hyperthyroidism, since excessive weight gain is a common complaint among these patients. Natural background radiation exposure accounts for an average of 3.1 mSv/yr with variations depending on where you live. Feeding an iodine-limited diet (Hills Prescription Diet y/d) can resolve clinical signs and lower thyroid hormone concentration. It is acceptable to feed your feline products containing at least 30% protein and less than 15% carbohydrates. And not only do we love the pets, we also love their people, and you are our reason for making this site. Domestic airline pilots are exposed to an additional 2.2 mSv per year, about the same dose as a brain CT. As you can see from the table below, the estimated risk of developing cancer from exposure to 0.1 Gy (= 100mSv), while it varies with the age of the individual, is something less than 1% for adults. All middle-aged and senior cats should receive a complete physical examination by a veterinarian every six months. As for equipment for tracking radioactive contamination, there really is no readily available "home-testing" equipment. However, the risk is minimal if your cat is otherwise healthy, and the initial diagnostic tests and treatment did not reveal any underlying conditions. . After administration of 131 Iodine, your cat is . If methimazole dosing is discontinued, hyperthyroidism will return. Radioiodine treatment avoids surgery, anesthesia, and anti-thyroid drugs. Some cats may experience side effects from medication, however, including vomiting, anorexia, fever, anemia, and lethargy. What is taken up by the thyroid will be released slowly over the next days/weeks to the other bodily fluids which is why they have the precautions that you describe.